Kin trc cho h thng dng nhiu

phn mm

Sch hng dn ngi thc hnh

Anthony J. Lattanze

Ngi dch: Ng Trung Vit

ARCHITECTING SOFTWARE

INTENSIVE SYSTEMS

A Practitioners Guide

Anthony J. Lattanze

ISBN 978-1-4200-4569-7

1. Software Engineering. 2. System Engineering. 3. Software Architecture.

QA76.758.L3285 2009 005.12--dc22 2008039859

Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com

v the Auerbach Web site at http://www.auerbach-publications.com

Xin knh tng

Thng v gia nh ti

i

Mc lc

Li ni u ....................................................................................................................... viii

Li cm t ......................................................................................................................... xii

Hng dn c gi .......................................................................................................... xiv

Phn I .................................................................................................................................. 1

Chng 1 Gii thiu .......................................................................................................... 3 Vng i kin trc ........................................................................................................... 6

Ch , mc ch v t chc ...................................................................................... 14

Chng 2 Kin trc c nh ngha ............................................................................ 16 Lch s ca cc khi nim h thng hin i ............................................................. 18

Kin trc h thng ...................................................................................................... 20

Kin trc s nghip .................................................................................................... 22

Lch s tm tt v phn mm hin i ....................................................................... 25

Hng ti kin trc H thng dng nhiu phn mm................................................ 26

Cp bc thit k .......................................................................................................... 28

Cu trc ...................................................................................................................... 31

Phn t ....................................................................................................................... 31

Thuc tnh thy c bn ngoi ca phn t ............................................................. 31

Quan h gia cc phn t ........................................................................................... 31

Chng 3 Dn li kin trc ............................................................................................. 35 Dn li kin trc c nh ngha .................................................................................. 36

Nhng ngi c lin quan .......................................... Error! Bookmark not defined.

Yu cu chc nng mc cao ...................................................................................... 38

Yu cu c tnh cht lng....................................................................................... 43

Rng buc k thut ..................................................................................................... 48

Rng buc doanh nghip ............................................................................................ 50

Tm tt ....................................................................................................................... 51

Chng 4 Cu trc kin trc .......................................................................................... 52 Cu trc v cnh quan ................................................................................................ 53

Cnh quan tnh ........................................................................................................... 54

Cnh quan ng ......................................................................................................... 55

Cnh quan vt l ......................................................................................................... 55

Cu trc v thuc tnh h thng ................................................................................. 60

Tch ri ...................................................................................................................... 61

Gn kt ....................................................................................................................... 62

C kt ......................................................................................................................... 62

Hp nht ti nguyn ................................................................................................... 62

Ri ti nguyn ............................................................................................................ 63

ii

D tha ...................................................................................................................... 64

Cu trc, kiu cch, v hnh mu ............................................................................... 64

Dng cu trc ............................................................................................................. 67

Khun kh thuyt phc cu trc ................................................................................ 68

Cnh quan .................................................................................................................. 68

Phn t v quan h ..................................................................................................... 70

Loi hnh .................................................................................................................... 70

Ng ngha ................................................................................................................... 71

Hiu qu c tnh cht lng ..................................................................................... 71

Hon cnh s dng ..................................................................................................... 71

Bin thin cu trc ..................................................................................................... 71

V d ng dng khun kh ........................................................................................ 72

Chin thut ................................................................................................................. 76

Tm tt ....................................................................................................................... 79

Chng 5 Cng vic ca Kin trc s ............................................................................ 81 Kin trc s lm g? ....................................................................................................... 81

K ngh yu cu ......................................................................................................... 82

Tham gia vo t qun l ............................................................................................. 82

Khi no chng ta lm kin trc s?............................................................................ 87

Hng dn cho thit k kin trc ............................................................................... 90

V d: SmartMarquee ................................................................................................. 94

Tm tt ..................................................................................................................... 119

Chng 6 Lm ti liu Thit k kin trc ................................................................... 121 Nhng ngi c lin quan ti ti liu kin trc ....................................................... 122

Khi no lm ti liu kin trc ................................................................................... 128

Ci g cn vit ra ...................................................................................................... 131

Cng c lm ti liu v UML .................................................................................. 135

Hng dn chung v vit k thut ............................................................................ 143

Cu trc ti liu ........................................................................................................ 149

Tm tt ..................................................................................................................... 152

Phn II ............................................................................................................................. 153

Chng 7 Phng php thit k ly kin trc lm trng tm ................................... 154 Tng quan v ACDM ............................................................................................... 156

Cc vai tr trong ACDM .......................................................................................... 160

Chng 8 ACDM Giai on 1: Khm ph dn li kin trc ..................................... 167 Mc ch .................................................................................................................. 167

Tin iu kin .......................................................................................................... 167

Hot ng chung ...................................................................................................... 167

K thut, khun mu, v hng dn ......................................................................... 167

Vt phm chnh yu nht ......................................................................................... 167

Hu iu kin ........................................................................................................... 168

M t giai on 1 ..................................................................................................... 170

Bn thit k chnh: Lp k hoch chin lc thit k .............................................. 171

Lp k hoch hi tho khu gi dn li kin trc .................................................... 177

Tin hnh hi tho khu gi dn li kin trc .............................................................. 183

Gii thiu v tng quan hi tho .............................................................................. 183

Tng quan sn phm hay h thng .......................................................................... 185

Nhn din m t chc nng...................................................................................... 185

iii

Nhn din yu cu c tnh cht lng .................................................................... 191

Nhn din rng buc doanh nghip ......................................................................... 194

Nhn din rng buc k thut ................................................................................... 195

Tm tt v cc bc tip .......................................................................................... 196

Hp nht d liu th ................................................................................................ 196

To ra v cp nht bn k hoch thit k ch .......................................................... 198

To ra lch biu ........................................................................................................ 202

Tc ng ca chi ph v lch biu c nh ln lp k hoch ACDM ....................... 208

Tc ng ca c t c sn trc ln qui trnh khu gi yu cu ACDM ............... 209

Tm tt ......................................................................................................................... 210

Chng 9 ACDM Giai on 2: thit lp phm vi d n ............................................ 211 Ch nh ....................................................................................................................... 211

Tin iu kin .............................................................................................................. 211

Hot ng chung K thut, khun mu v hng dn ................................................. 211

Vt phm chnh ............................................................................................................ 211

Hu iu kin ............................................................................................................... 213

M t giai on 2 ......................................................................................................... 213

Lp k hoch giai on 2 ......................................................................................... 214

Phn tch ................................................................................................................... 216

Hng dn cho pht trin trng hp s dng t m t vn hnh .......................... 216

V d v trng hp s dng ................................................................................... 222

Lm ti liu .............................................................................................................. 242

Tm tt ......................................................................................................................... 246

Chng 10 ACDM Giai on 3: To ra/Ci tin Kin trc ....................................... 248 Ch nh ....................................................................................................................... 248

Tin iu kin .............................................................................................................. 248

Cc hot ng chung K thut, khun mu v hng dn ........................................... 248

Vt phm chnh ............................................................................................................ 251

Hu iu kin ............................................................................................................... 251

M t giai on 3 ......................................................................................................... 251

Lp k hoch giai on 3 ............................................................................................. 252

Thit k kin trc phng chng ................................................................................... 255

Thit lp hon cnh .................................................................................................. 255

Phn r lp ................................................................................................................ 257

Ci tin kin trc phng chng ................................................................................ 259

Giao din phn t ..................................................................................................... 260

Tnh truy nguyn c ............................................................................................. 261

Khi no chng ta xong vi thit k? ............................................................................ 265

Cp nht bn k hoch ch .......................................................................................... 266

Tm tt ......................................................................................................................... 266

Chng 11 ACDM Giai on 4: nh gi thit k kin trc .................................... 268 Ch nh ....................................................................................................................... 268

Tin iu kin .............................................................................................................. 268

Cc hot ng chung K thut, khun mu v hng dn ........................................... 268

Vt phm chnh ............................................................................................................ 268

Hu iu kin ............................................................................................................... 269

M t giai on 4 ......................................................................................................... 270

So snh cc phng php nh gi .............................................................................. 271

Lp k hoch giai on 4 ............................................................................................. 273

Tm l v nh gi thit k ........................................................................................... 276

iv

Con ti khng xu! ................................................................................................... 276

Th ........................................................................................................................ 277

Ti mi gii hn anh ................................................................................................ 277

Ta c b qua n i.................................................................................................... 278

Hang em High ......................................................................................................... 278

Ta sa n by gi i ................................................................................................. 278

Chuyn thi gian ...................................................................................................... 279

Tin hnh hi tho nh gi thit k kin trc ............................................................. 279

Ngi ch tr ............................................................................................................ 281

Ngi trnh by kin trc ......................................................................................... 281

Ngi ghi ................................................................................................................. 281

Ngi gi qui trnh nh gi .................................................................................... 281

Ngi gi thi gian .................................................................................................. 282

Ngi hi ................................................................................................................. 282

Bc 1: Gii thiu ................................................................................................... 283

Bc 2: Kim im hon cnh doanh nghip v rng buc doanh nghip.............. 286

Bc 3: Kim im yu cu v rng buc k thut .................................................. 288

Bc 4: Trnh by tng quan kin trc .................................................................... 289

Bc 5: Phn tch chc nng ................................................................................... 290

Bc 6: Phn tch cu trc: Phn tch cu trc h thng dng Kch bn c tnh cht

lng ........................................................................................................................ 296

Bc 7: Tm tt: Kim im vn c ghi li ................................................... 301

Li khuyn cho ngi hi ........................................................................................ 301

Xem xt k tnh nht qun ........................................................................................ 302

Qu nhiu hay qu t chi tit .................................................................................... 303

Hng dn v t cu hi trong phn tch chc nng .............................................. 304

Hng dn v t cu hi trong phn tch cu trc ................................................. 305

Li khuyn cho ngi ch tr ....................................................................................... 308

V t ........................................................................................................................ 309

Lng nghe ................................................................................................................. 309

Bo v ngi mong manh ........................................................................................ 311

Ch ti m hiu v li .......................................................................................... 311

Qun l cc hnh vi khng hu ch .......................................................................... 312

Bit bn thn mnh ................................................................................................... 313

Cp nht bn k hoch ch ...................................................................................... 314

Tm tt ......................................................................................................................... 314

Chng 12 ACDM Giai on 5: Quyt nh lm/khng lm .................................... 316 Ch nh ....................................................................................................................... 316

Tin iu kin .............................................................................................................. 316

Cc hot ng chung K thut, khun mu v hng dn ........................................... 316

Vt phm chnh ............................................................................................................ 316

Hu iu kin ............................................................................................................... 316

M t giai on 5 ......................................................................................................... 318

Lp k hoch giai on 5 ............................................................................................. 319

Cuc hp phn tch vn ........................................................................................... 320

quyt nh lm/khng lm ........................................................................................... 323

Chng ta cha? .................................................................................................... 324

Cp nht bn k hoch thit k ch ............................................................................. 326

Tm tt ......................................................................................................................... 327

Chng 13 ACDM Giai on 6: Thc nghim ........................................................... 329

v

Ch nh ....................................................................................................................... 329

Tin iu kin .............................................................................................................. 329

Cc hot ng chung K thut, khun mu v hng dn ........................................... 329

Vt phm chnh ............................................................................................................ 329

Hu iu kin ............................................................................................................... 329

M t v giai on 6 ..................................................................................................... 329

Lp k hoch giai on 6 ............................................................................................. 332

Lp k hoch v thc thi thc nghim ......................................................................... 334

Khun mu lm thc nghim ....................................................................................... 336

Qui trnh lm thc nghim ........................................................................................... 338

Chp thun thc nghim .............................................................................................. 339

Tin hnh thc nghim ................................................................................................ 339

Hu thc nghim .......................................................................................................... 342

Cp nht bn k hoch ch .......................................................................................... 345

Tm tt ......................................................................................................................... 345

Chng 14 ACDM Giai on 7: Lp k hoch sn xut ............................................ 346 Ch nh ....................................................................................................................... 346

Tin iu kin .............................................................................................................. 346

Cc hot ng chung K thut, khun mu v hng dn ........................................... 346

Vt phm chnh ............................................................................................................ 346

Hu iu kin ............................................................................................................... 346

M t giai on 7 ......................................................................................................... 348

Lp k hoch giai on 7 ............................................................................................. 350

Hi tho lm quen kin trc ..................................................................................... 350

Hng dn v xem xt lp k hoch chung ................................................................. 351

Lch biu sn xut ........................................................................................................ 354

c lng Delphi bng rng cp phn t .................................................................... 357

Lp k hoch kim th ................................................................................................. 360

Cc phn t khc ca bn k hoch sn xut ............................................................... 362

Cp nht bn k hoch thit k ch ............................................................................. 362

Tm tt ......................................................................................................................... 362

Chng 15 ACDM Giai on 8: Sn xut ................................................................... 364 Ch nh ....................................................................................................................... 364

Tin iu kin .............................................................................................................. 364

Hot ng chung K thut, khun mu v hng dn ................................................. 364

Vt phm chnh ............................................................................................................ 364

Hu iu kin ............................................................................................................... 364

M t giai on 8 ......................................................................................................... 366

Lp k hoch giai on 8 ............................................................................................. 367

Nht qun thit k ........................................................................................................ 367

Tch hp phn t .......................................................................................................... 368

Theo di n lc sn xut .............................................................................................. 369

Tm tt ......................................................................................................................... 371

Phn III ........................................................................................................................... 372

Chng 16 Dch chuyn thc hnh, qui trnh v phng php thit k .................. 373 Chin lc dch chuyn chung ..................................................................................... 374

Tc nhn thay i ..................................................................................................... 374

Chin lc cho thay i ............................................................................................... 376

Bo tr ...................................................................................................................... 376

Tuyn c s .............................................................................................................. 377

vi

Bn k hoch ............................................................................................................ 378

Thc thi .................................................................................................................... 381

Suy ngm ................................................................................................................. 382

tng thc hnh cho dch chuyn v chp nhn ...................................................... 383

p dng hiu bit thng mt cch t do ................................................................ 384

Gii thiu cc khun mu ........................................................................................ 385

To ra con ng ngh nghip k thut ................................................................... 385

Thit lp T thit k kin trc .................................................................................. 386

Th ch ho nh gi kin trc ................................................................................ 386

Ro chn cho chp nhn: Phn thc hnh thng thng ............................................. 388

Khng tng xng hon cnh doanh nghip ........................................................... 388

B ............................................................................................................................. 389

Li ni i bi .......................................................................................................... 390

Phn mm l d ........................................................................................................ 390

U quyn theo d xung ........................................................................................... 392

Bt n ca ti Grrr! ............................................................................................. 393

Thiu ti nng c hi t ....................................................................................... 394

Tip th v gin on k ngh ................................................................................... 394

o to v lp k hoch dch chuyn ....................................................................... 395

Tm tt ......................................................................................................................... 397

Chng 17 Xem xt thit k khc: tha t, thit k theo la chn, v bo tr ........ 398 Thit k vi phn tha t ............................................................................................. 398

Php l phn tha t ................................................................................................. 401

Phn tch tun th ..................................................................................................... 404

Cc xem xt thit k khc ........................................................................................ 405

Thit k theo la chn .............................................................................................. 407

Sai lm thng gp ...................................................................................................... 413

T cch phn t thng mi vi ACDM ..................................................................... 415

Bc1: Nhn din phn t v sn phm ng c vin .............................................. 416

Bc 2: Thit lp tiu ch so snh ............................................................................ 416

Bc 3: To ra ma trn so snh ............................................................................... 418

Bc 4: Trc nghim tnh nng v thuc tnh ng c vin ..................................... 424

Chin lc cp ti s khng tng hp kin trc ................................................... 426

Phn mm Wrappers ................................................................................................ 427

Trung gian ................................................................................................................ 427

Tng qui m ACMD .................................................................................................... 429

ACDM trong bo tr ..................................................................................................... 433

Tm tt ......................................................................................................................... 435

Chng 18 Dng ACDM vi cc khun kh pht trin phn mm ......................... 436 Thut ng ..................................................................................................................... 437

Qui trnh nng so vi nh ......................................................................................... 439

ACDM v khun kh qui trnh pht trin phn mm .............................................. 444

ACDM v thc .................................................................................................... 445

ACDM v lp trnh cc oan (XP) .......................................................................... 446

ACDM v Scrum ..................................................................................................... 450

ACDM v Qui trnh phn mm t (TSP) ................................................................. 454

ACDM v RUP ........................................................................................................ 457

ACDM v CMMI ..................................................................................................... 462

Tm tt ......................................................................................................................... 464

Ti liu tham kho ......................................................................................................... 467

vii

Ch mc (ting Anh) ............................................................. Error! Bookmark not defined.

viii

Li ni u

Ngy nay nn vn minh ca chng ta ph thuc cao vo cc h thng dng nhiu

phn mm. H thng dng nhiu phn mm l nhng h thng ph thuc cao vo kt cu

nn tnh ton v phn mm cho chc nng c bn m chng cung cp v cc thuc tnh

chng s hu. Thit k kin trc ca cc h thng dng nhiu phn mm l b mn tch

ri v phn bit bn trong k ngh phn mm mi qung 15 tui, tu theo bn hi ai v h

nh ngha thit k kin trc th no. Thit k h thng ra i qung nm 1945 v ni

ln chnh thc t cc phng th nghim RAND xy dng v kh v h thng d liu ln

cho chnh ph. Phn nhiu trong nhng cng trnh sm ny trong thit k h thng v k

ngh c ti tr bi B quc phng M. Thit k cho cc h thng phc tp ln vo

nhng nm u c xu hng hi t vo phn hoch h thng thnh cc yu t c in

t, v tch hp cc yu t ny vo trong h thng. Vo lc vic mua v bo tr phn

cng t ng ho d liu l rt ln v t. Cc ng dng phn mm cn tng i nh v

vn khng ln v phc tp v chi ph so vi phn cng. Cch tip cn k ngh h thng

v k thut thi u ni ln t min ny v b nh hng su sc bi cc t chc

chnh ph, qun s, v doanh nghip ln. Cng ng k ngh h thng vn cn gi li

nhiu tinh thn ca min ny ti ngy nay. Khi yu cu h thng tr nn ngy cng i

hi hn, v phn cng my tnh tr nn r hn v nh hn, nhu cu v phn mm trong

cc h thng phc tp ny tng trng theo hm m. ng dng phn mm tng

trng v phc tp, v chi ph cho phn mm tng ln nhanh chng theo hm m.

Theo nhiu cch, cch tip cn v phng php k ngh h thng truyn thng, mc du

vn cn tranh ci, khng cp ti thit k phn mm mt cch h thng. V vai tr

v tm quan trng ca phn mm trong cc h thng hin i v tc ng ln lao nu

c thit k km, h thng phi c thit k mt cch nguyn khi. Cch tip cn k

ngh h thng truyn thng ni ln t thit k cc h thng c in t, v thit k phn

mm h thng b cng ng ny b li ng sau trong nhiu nm. iu m kinh

nghim ch ra l ch phn cng my tnh, ngoi vi, phn mm, v cc b phn c

in t khc ca h thng khng th c thit k v xy dng ch c lp m u tin

khng thit k kin trc tng th ca h thng. iu ny l ng cho h thng dng nhiu

phn mm nhng hay hng theo CNTT.

Th trng ngy nay l khc rt nhiu so vi n vy nhng nm u ca thit k

h thng. Ngi tiu th phn mm ln nht khng cn l cc t chc chnh ph, m thay

vo l th trng ngi tiu th rng hn. T ng ho d liu khng cn trong tay

vi ngi u t. Gn nh mi t chc doanh nghip v chnh ph u yu cu phn mm

v phn cng bt k ti kch c ca min. Bi v cng nghip phn mm khng cn b chi

phi bi cc ng dng chnh ph v qun s, nhng min ny khng cn dn li th

trng hay lnh o pht kin vi cc chun pht trin, ngn ng, h iu hnh, phn

cng my tnh, vn vn. Nh li ngn ng Ada v h iu hnh POSIX tr v nhng nm

1980 m xem? Cc t chc chnh ph kh m thc hin nhng loi u quyn su rng ny

ix

ngy nay. Ngy nay, pht kin c dn li bi th trng rt rng v khng cn xy ra

ch trong cc phng th nghim ca chnh ph v i hc. Cc sn phm mi v pht kin

thng c a vo bi cc cng ti nh v ln, cng nh cc nh doanh nghip c nhn

- theo ngha en l bt k ai c tng v c my tnh u c kh nng lm thay i v

nh hng ti th gii bng phn mm. S khc bit hon ton gia cc h thng dng

nhiu phn mm thi u v hin nay l ch cc h thng hin nay thng dng hng

triu, hay chc triu dng m. Trong hu ht cc sn phm v t chc, phn mm khng

l tu chn - n nm ti trung tm ca chc nng sn phm. t ngy nay s khng khi

ng v my bay s khng bay nu khng c phn mm. H thng tin hin i khng ch

l h thng c s d liu ln, b kt trong nhng to nh chnh ph ln, ngn hng, hay

trung tm x l bo him - nhng h thng ny trong nh chng ta, t, my bay, my

tnh bn, theo ngha en l mi ni! Cc tiu dng ngy nay, t, h thng tin, v

cc sn phm khc l c nhiu kh nng hn, thng minh hn, an ton hn, v hiu qu

hn trc y. T ng ho d liu khp ni nh hng v lm thay i x hi - theo

nhiu cch n nh ngha li s tn ti con ngi. C th cho con ngi trao i, tin

hnh kinh doanh, v chi theo nhng cch m ch mi 20 nm trc khng bao gi c th

m ti c.

Mi nng lc ny ti vi ci gi v phc tp. Mc cho mch tch hp thm ch

phc tp hn v cc b x l trn mt chip, phn cng thng khng phi l ngun ca

phc tp h thng v chi ph. Chi ph ca phn mm vt qu chi ph ca phn cng t

lu trc y. Thng chnh phn mm mi l ngun gc ca vn thit k v pht trin

- thng tn km l thit k, cu trc, v bo tr theo cch ng thi gian v hiu qu-

chi ph. Cch tip cn k ngh v k thut h thng c ngun gc ca chng trong phng

php thit k phn cng truyn thng v c xu hng tru tng khi thit k phn mm

h thng. Bi v phn mm ct ngang qua nhiu phn t ca h thng, phn mm xng

ang c s ch nhiu nh bt k phn t c in t no khc ca h thng cp

ti nhng phc tp h thng rng hn. Mc du k thut thit k phn mm ni ln,

chng c xu hng tru tng khi mi quan tm thit k h thng v hi t vo chc

nng, th tc, hay mc phng php ca thit k. iu ny l qu chi tit v hn hp

cp ti thit k phn mm h thng.

Chc chn phn cng l phc tp, nhng thit k phn cng tng i c hiu

r. Cc phn t ca h thng phn cng l nhng hng ho m ni ng ngha l c

bn nh u, go v ng th trng m. Vi phn mm li l cu chuyn khc. Phn

mm l linh hn ca nhng my phc tp ny - v ging nh linh hn con ngi, chng ta

khng th bt c phn mm, n khng c trng lng, n khng th c quan st, vy

m s hin din ca n l khng th ph nhn c v xc nh ra tnh cch v hnh vi

ca my. Phn mm l a chiu. iu chng ta thy trong cc thut ng v cu trc tnh

nh m l khc vi iu chng ta thy khi m c bin dch v thc hin. Bn cht te

ny ca phn mm l l do ti sao kh thit k v xy dng h thng dng nhiu phn

mm. ng ti minh ho vn ny v vic hiu phn mm mt cch hon ho. ng ti

l mt ngi thc hnh cc oan v cc phng tin gin d nht, vy m c tri thc thc

hnh phong ph v c cm nhn thng thng ti t nhiu nm lm vic nh nng dn

thc th v qu ng. ng y c th hiu v nh gi cao my bay ang bay trong khng

trung v vai tr m cnh gi trong vt l ca vic bay, nhng ng y khng th no hiu

c h thng kim sot phn mm. Tnh khng thy c v bn cht a chiu ca phn

mm vi phm hiu bit ca ng y v th gii. Bi v thiu bng chng vt l cho phn

mm, ng y bao gi cng ngn ngi theo cch no v chn la ngh nghip ca ti

lm k s phn mm v thy gii thch ca ti v phn mm l khng th no hiu c

mi ti ngy ng cht. Trong tm tr thc hnh ca mnh, ng khng th hiu c ti sao

x

mi ngi li tr lng hu hnh cho chu ng y thit k v xy dng ci g m

khng th nhn thy c, khng cn ong c, hay cm trong tay ng y. Mc du ng

sung sng l ti lm ra kh tin, ng khng th ng m ngh rng ti c mnh li

qung co ang lm! V mc du ng khng bao gi ni nhiu, ti c thuyt phc l

ng s mc no a chu ng tr thnh k bp bm.

Ti mc no , y l vn chng ta i din nh l kin trc s cho h thng

dng nhiu phn mm. Cc k s v kin trc s thng xuyn c gng tm ra cc k

thut, phng php, v tru tng ho thit k v phn tch cc h thng phc tp dng

nhiu phn mm - iu ny bao gm c phn mm h thng m to kh nng cho h thng

lm iu n c xc nh lm. Thit k phn mm ni ln song song vi k ngh

h thng, nhng hi t vo cc mi quan tm thit k m chi tit. N bt u vi cc

kiu d liu tru tng vo cui nhng nm 1960 v tip tc ti ngy nay vi cch xy

dng da trn cu phn. Theo nhiu cch cng ng k ngh h thng v thit k phn

mm hp nht li ti mc no . Cc cch tip cn k ngh h thng c nhiu

ngi coi nh khng thch hp cho thit k cc h thng cng ngh thng tin (CNTT)

hin i. Hiu theo ngha hp, cng ng kin trc s nghip ni ln qua 10 nm qua

hay i loi nh vy cp mt cch xc nh ti thit k cc h thng CNTT. Kin

trc s nghip ni ln t cc khi nim k ngh h thng truyn thng vi cc khi nim

thit k v k ngh phn mm. Tuy nhin, kin trc s nghip c xu hng hi t vo k

ngh qui trnh doanh nghip. N c 13 nm t khi cun sch u tin v thit k

kin trc ca h thng dng nhiu phn mm bt u ni ln. Theo nhiu cch, ngh thut

v khoa hc v thit k h thng dng nhiu phn mm thc hin mt s bc i ln

trc. Tuy nhin, nhiu tht vng ln vn cn vi kin trc s thc hnh, v vn c con

ng di cn i.

Chnh thut ng kin trc vn cn c nh ngha km, v vai tr ca kin trc s trong hon cnh t chc vn cn m cho tranh ci. Chng ta c t dt

khot, hnh thc ho v tho thun rng ri v cc nguyn l u tin v thc

hnh tt nht m kin trc s c th gi l quyt nh thit k ca h.

Mc du kh tin, nhiu t chc trn khp th gii khng coi k ngh phn mm l mi quan tm hay b mn k ngh hng nht. Cng nhng t chc ny phn

ln b qua cc thc hnh k ngh phn mm c k lut c bn v thit k kin

trc, v sn phm cng h thng ca h thng b mc phi cc vn phn

mm.

C rt t cng c lm ti liu cho thit k ca h thng dng nhiu phn mm. Kin trc s thng dng mt t hp cc cng c, phng php, v qui trnh m

c gn li vi nhau theo cch khng th thc. iu ny lm cho kh nm

c chn la thit k v trao i chng vi nhng ngi thc hin.

Ti phi rt r rng rng cun sch ny khng dnh ring cho k ngh phn mm

nhng, k ngh h thng hay k ngh phn mm, m l v xy dng h thng dng nhiu

phn mm, iu c bao gm h thng CNTT, b m phng hay h thng nhng. Mc ch

chnh ca cun sch ny l trnh by cc nguyn l thit k kin trc p dng c cho bt

k t chc no hay min xy dng h thng dng nhiu phn mm. Nhiu chng trnh

khoa hc my tnh i hc ngy nay thin v min CNTT, cho nn nhiu gi thit c

nu ra bi cc nh khoa hc my tnh c o to c th khng hp thc trong cc min

khc, nh h thng nhng. Cc gi thit ngn ng, ti nguyn sn c, iu kin mi

trng, hiu nng, an ninh, tnh sn c, v cc loi yu cu khc l rt khc trong CNTT

v min nhng. Mc ch then cht ca cun sch ny l cung cp cc nguyn l m s

phc v cho kin trc s xy dng ra h thng dng nhiu phn mm cho cc cc oan

xi

ny v bt k nhng ci gia. Vi hiu bit c nguyn l v thit k, kin trc s c th

lm du bn nng phi l tr phn ng v c chun b tt hn cp ti min rng

hn cc vn thit k bt k ti hon cnh doanh nghip hay kinh nghim min ca h.

Tho mn cc mi quan tm h thng rng nh hiu nng, an ninh, tnh sn c, vn vn l

khng th c nu khng c thit k kin trc ton th, iu t ra khun kh cho thit

k chi tit v sau v thc hin!

xii

Li cm t

Cng trnh ny i din cho by nm nghin cu, thc hnh cng nghip, v vit m

l thuc vo nhiu ngi v t chc, nhng ngi h tr cho cng trnh ny qua n

lc ca h, s kin nhn, phn hi, tng, v nhiu ng gp khc. Ni ring ti cm n

Bob Gazda thuc Inter-digital LLC, ngi l tin phong v Phng php thit k ly

kin trc lm trng tm c m t trong Phn III. Bob l ngi duyt ban u v Phng

php thit k ly kin trc lm trng tm, v ph bnh ca ng y cung p thng tin gi

tr ci tin n. Ti cm n cng ti Sony Corporation v nhiu c hi h cung cp cho

ti tng tc vi cc k s ng cp th gii v v s cn mn dng nhiu phng php

c m t trong cun sch ny. Ni ring, ti xin cm n Minori (Micha) Endo, ngi

c th ho thnh ngi tin phong, lm vic khng mt mi ci tin cch cc k s

Sony thit k v xy dng h thng dng nhiu phn mm. Cng ti Sony, ti cm n

Toshiya (Toshi) Hasegawa; anh y l mt kin trc s c ti l c duyt bn tho ny.

Ti mun cm n cc k s ti LG Osan, Hn Quc, nhng ngi cng ng gp

bng vic dng cc phng php c m t bn trong cun sch ny v cung cp phn

hi c gi tr. Matthew Bass ca Siemens Corporate Research cng ng vai tr th

nghim trong pht trin cun sch ny bng vic cung cp nhiu c hi tng tc vi cc

k s Siemens trn khp th gii v ngi cng gii thiu ti vi nh xut bn, John

Wyzalek ti Taylor & Francis. John l mt ngi tuyt vi v kin nhn lm vic

trong tin trnh cng thng khi vit ra cun sch ny - ti gii thiu v John cng nh

Taylor & Francis v mi vic gy hng khi cho cc tc gi.

Cun sch ny chc khng th c c nu khng c nhiu sinh vin hc chng

trnh thc s v K ngh phn mm (MSE) ti Carnegie Mellon University (CMU) trong

mi nm qua v cc i hc i tc ca chng ti ti Hn Quc, B o Nha v n .

Nhiu sinh vin MSE t khp th gii ng gp ht sc nhiu trong thi gian bng

vic th cc phng php v k thut a dng c m t trong cun sch ny v cung

cp phn hi gi tr trc vic th cng nghip bt u. Ti xin cm n Eunjeong Choi,

Jihyun Lee, Hye Eun You, Taeho Kim, v Woo-Seok Choi t i hc thng tin truyn

thng (ICU), i hc i tc ca chng ti Hn Quc. Nhng ng gp c nhn ny

gip hnh thnh nn Chng 18.

Ti xin cm n cc ng nghip ca ti CMU v h tr v khuyn khch ca h

v s dung th trong khi ti giu mt v vit nhiu phn ca cun sch ny vo ma h

2007: David Garlan, Mel Rosso-Llopart, Gil Taran, Dave Root, Jane Miller, Ellen Saxon,

v Linda Smith. Mt c quyn v vinh d l c lm vic vi David Garlan v dy kin

trc phn mm vi ng y trong chng trnh MSE ti CMU - mt ni tuyt vi lm sao

cho kin trc s ! Nhiu ng nghip ca ti ti Vin K ngh phn mm (SEI) cng

gip hnh thnh nn cch ngh ca ti nh mt kin trc s v nh hng ti

phng php v k thut c m t trong cun sch ny. Ni ring, ti xin cm n Mark

xiii

Klein, Scott Hissam, Felix Bachmann, v Len Bass thuc SEI, ngi nh ngi thy km

d n cung cp phn hi c gi tr v Phng php thit k ly kin trc lm trng tm.

Cng ti CMU, ti xin cm n John Kang, Jiyeong Yoon, John Grasso, v cn b iu

hnh gio dc: Ann Papuga, Beverly Flaherty, v Cathy Baek. Nhng ngi bn ny

cung cp cho ti nhng c hi qu gi lm vic vi cc t chc v k s trn khp th

gii. Nhng c hi ny chng t l gio dc cc k c gi tr v m mt cho ti v

cch h thng c thit k v xy dng bn ngoi lnh th M. iu ny c nh

hng su sc v su lng ln ti nh mt k s, kin trc s, v thy gio, v theo cc

phng php v k thut c m t trong cun sch ny.

Cui cng, nhng quan trng nht, ti phi cm n gia nh ti, Karen, Anthony, v

Nathaniel Lattanze, v s dung th cho nhng gi di ti xa khi h, i pht trin v kim

th cc khi nim ny, v nhiu gi kh khn dnh vit chng ra trong cun sch ny.

xiv

Hng dn c gi

Ch nh ca cun sch ny l hi t vo thit k kin trc, c lp vi min, m

thc ngn ng, cng c, hay cc loi thin kin tng t khc. Hi vng l thit lp ra cc

nguyn l s to kh nng cho ngi k s thit k h thng dng nhiu phn mm tip cn

ti thit k theo cch c lp v khng thin lch; hiu nhng mi quan tm no nn nh

hng ti quyt nh thit k; bit tu chn thit k no l sn c vo bt k im no;

nhng b tr mang nng nh lng v vic phn on tt hn gia cc tu chn thit k;

v to ra thit k h thng ti u hn. Trong khi cun sch ny chc chn c th c

dng trong mn hc tt nghip v thit k kin trc, ni dung nguyn bn ca n l a

cc nguyn l thit k kin trc thc hnh vo tay nhng ngi hnh ngh. Cun sch ny

c chia thnh ba phn chnh:

Phn I (Chng 16): Hi t ca Phn I l vo nh ngha kin trc v trnh by cc

khi nim c bn ca thit k kin trc cho h thng dng nhiu phn mm. iu ny bao

gm cc ch v dn li kin trc, cu trc kin trc v hng dn nn tng cho thit k

kin trc.

Phn II (Chng 715): Trong phn ny, Phng php thit k ly kin trc lm

trng tm c trnh by. y l mt khun kh c kim th cng nghip cho thit

k kin trc ca h thng dng nhiu phn mm. Tng giai on ca phng php ny

c m t cng vi mi khun mu, danh sch kim v hng dn h tr.

Phn III (Chng 1618): Phn ny c dnh cho vn thc hnh v chp nhn

thc hnh thit k kin trc c k lut v dng Phng php thit k ly kin trc lm

trng tm vi s tn ti ca cc qui trnh pht trin t chc hin c.

c gi c khuyn nn c tng phn theo th t trnh by. Phn I thit lp

cc khi nim then cht v t vng c dng trong sut cc phn II v III. Bi v

Phng php thit k ly kin trc lm trng tm c cc giai on c xc nh r, tng

giai on nn c c theo trnh t c trnh by trong phn II. Mt khi cc nguyn l

thit k kin trc then cht v Phng php thit k ly kin trc lm trng tm c

hiu, nhiu cch dch chuyn v dng cc phng php ny c thm d trong Phn III.

1

PHN I

2

3

Chng 1 Gii thiu

T lc ban u c gi rng chng ta l quc gia ca nhng ngi nghip d.

Archibald Philip Primrose, Earl of Rosebery (18471929)

Chnh t kin trc gi ln nhiu hnh nh trong tm tr ca k s phn mm ngy

nay. Khng may, him khi c hiu bit chung v ch xc ci g c ng bi thut ng

kin trc, v ngha ch xc ny thng tu thuc vo hon cnh n c dng. n

chng ny, t kin trc tr thnh con tu rng trong ngha c rt vo bi nhng

ngi gii nht trong cc k s, ngi qun l, ngi tip th, hay nhng ngi c lin

quan khc - thng do thi thc ca tnh th. Thut ng kin trc c dng bi cc k s

phn cng m t thit k chip IC, cu trc c hc, mch, v cc b phn c in t v

cc mnh ca h thng. Di dng vt phm thit k phn mm, kin trc in hnh c

dng ch thit k th m t cho cch phn hoch th ca h thng thnh tuyn tp cc

yu t no m c th c hng theo khi vit m, khi chy hay cu trc vt l. Cc

m t h thng phn mm thng bao gm nhng hnh v hp v ng khng hnh thc

v li dn thng c coi nh kin trc ca h thng. Mc du c nhiu hp dn trc

gic, nhng m t ny thng thiu hnh thc, chnh xc, hay nht qun c bn, li

vic din gii v thit k cho cht ny ra ca c gi. Khng may, cc c gi khc

nhau din gii nhng vt phm ny mt cch khc nhau, ph hoi ngm thit k nh

phng tin hiu qu cho trao i v iu s c xy dng v lm ny sinh niu vn

xy dng. nh ngha cc thut ng l chc nng c bn ca ngn ng cho php con

ngi trao i cc khi nim phc tp bng vic dng t c s tho thun v ngha. Bi v

thut ng kin trc b cc k lm dng v qu ti, thng c nhiu ln ln khi cc k s

khc nhau nh m t thit k kin trc ca h thng m h ang xy dng - cho d n l

cng h thng. Cc cng ng k ngh a dng, cc min, v ngay c cc t chc cng qui

cho cc ngha khc nhau vi thut ng kin trc. Chnh tiu cun sch ny, Kin trc

cho H thng dng nhiu phn mm, c th c din gii theo nhiu cch. Vic u tin

ca chng ta s l phn loi ra cc khi nim v thut ng c bn v c gng a ra mt

s ranh gii v loi kin trc no chng ta s cp ti trong cun sch ny; nhng trc

ht, chng ta hy nhn vo tiu ny k hn mt cht. nh ca thut ng lm kin

trc l mt ng t ngha l thit k kin trc ca h thng. Nh tiu ny ch ra, hi t

ca cun sch ny s l kin trc ca h thng dng nhiu phn mm, nhng iu ny

ngha l g?

4

H thng dng nhiu phn mm l bt k h thng no tu thuc cht ch vo phn

mm, phn cng tnh ton lin kt, h iu hnh, d liu, v i loi nh vy em dch

v ti nhng ngi lin quan. Mc du nhiu tc gi trong cng ng k ngh phn mm

cp ti mi quan tm thit k v Web-, Internet-, v cc h thng v ng dng ly cng

ngh thng tin (CNTT) l trung tm, cch ni ny s hi t nhiu v i th ln thit k

kin trc ca nhng h thng dng nhiu phn mm ny khc m c tch hp vo trong

cc sn phm nh my bay, t, t lnh, h thng kim sot mi trng, v bt k h

thng tng t no tu thuc vo phn mm em ti dch v cho ngi dng. Phn

mm l linh hn ca cc h thng ny v chu trch nhim trong nhiu trng hp cho

cc dch v c bn nht m nhng h thng ny cung cp. Hin nhin, chng ta s khng

tho lun v thit k kin trc c bit ca mi h thng ny, nhng cc h thng t cc

min a dng s c dng nh cc v d minh ho cho cc khi nim thit k kin

trc tng qut p dng c trong bt k min k ngh phn mm no. Cc nguyn l thit

k h thng dng nhiu phn mm khng phi l chuyn cho min no. Cc nguyn l

thit k p dng cho h thng qun l quan h khch hng ba bn cng p dng cho cc b

iu khin ng c t. Vi l do ny, cc nguyn l thit k v cc qui trnh thit k s l

hi t chnh ca cun sch ny. Khng c nguyn l hng dn trc gic ca ngi

thit k, tt c cc thit k v gii php ca ngi s c v nh nhau bt k ti lc thit

k p t ln chng. Trc gic thun khit c th phc v tt cho chng ta khi cc lc

thit k l hng s; tuy nhin, tin b cng ngh, dch chuyn m hnh doanh nghip, cu

trc t chc, nhu cu th trng, v vn vn thng xuyn lm thay i lc thit k ti

cng vic thit k. iu c th l trc gic tt cho sn phm cui, th trng, t chc, vn

vn c th khng cn tt cho sn phm tip. Do c nhu cu v hng dn cc nguyn l

thit k v qui trnh c k lut. Hi t ca cun sch ny khng ch lm thit k phn mm

ch c lp. Gn nh khng th no lm thit k kin trc cho h thng dng nhiu phn

mm thit k phn mm m khng xem xt ti kt cu nn h thng rng hn (phn

cng, ngoi vi, v.v.), h iu hnh, cc yu t tha t (phn cng v phn mm), v nhiu

yu t khc. Trong thc t, thit k h thng dng nhiu phn mm him khi l mt chiu,

m thng phn cp, ni ngi thit k ny rng buc ngi thit k khc pha h lu,

ngi ny li rng buc ngi thit k hay ngi thc hin khc, v c th. i khi phn

cng v h iu hnh c chuyn bit ho nh cc rng buc, thng bi cc nh thit

k khc, trc khi kin trc s phn mm thm ch ngh ti thit k. Phn mm khng th

thc hin trong khng trung, v do vy, kin trc s xy dng h thng phn mm thng

vo v tr phi la chn cc yu t vt l ca h thng, nh my tnh, cm bin, kt cu

nn mng, v thit b ngoi vi. Trong cc trng hp ny, d mt rng buc hay chn la

thit k, phn cng l mt phn quan trng ca h thng dng nhiu phn mm. Chn la

hay rng buc phn cng v h iu hnh tc ng su sc ln thit k kin trc phn

mm v phi l mt phn ca thit k kin trc ca h thng hay cc h thng. Mc du

quan trng, hi t ca cun sch ny khng l v thit k chi tit ca phn t phn cng,

nhng thay v th l tc ng ca nhng phn t ny p t ln kin trc s khi thit k h

thng dng nhiu phn mm.

Cu hi t nhin trong tm tr ca hu ht cc k s ti im ny l, Thit k chi tit

khc vi thit k kin trc th no? Cu tr li nhanh chng l ch khng phi mi mi

quan tm thit k u v kin trc v bn cht. Thit k kin trc l ch m ngi k s

chuyn t khng gian yu cu sang khng gian thit k. Thit k kin trc phn mm nn

phc v nh bn nhy cho thit k chi tit hay hot ng thc hin v nn nh ngha r

rng bin gii cho nhng ngi thit k v thc hin pha h lu. H thng dng nhiu

phn mm c xy dng m khng c kin trc phn mm c thit k c ch s c

nhng thuc tnh ni ln m s khng c hiu r bi v chng khng c thit k

trong h thng. Cc thuc tnh nh hiu nng, tnh sn c, tnh sa i c, tnh an ninh,

5

vn vn phi c thit k trong h thng p ng nhu cu ca nhng ngi c lin

quan, ngi s dng, ngi mua, v ngi bo tr h thng. Nu khng c thit k

trong h thng, vic hiu v sa nhng thiu st h thng trong cc thuc tnh ny thng

thnh vn , v trong mt s trng hp l khng th c cch sa cha. Trong h thng

c bt k hu qu no, cc thuc tnh nh nhng thuc tnh ny khng th c t ti qua

thit k mc chi tit v chng yu cu vic iu phi rng qua phn ln hay tt c cc

phn t h thng. Trong trng hp cc cu trc m chi tit (nh i tng, lp, hm,

v.v.) c thit k u tin, cu trc h thng kt qu l ln v phng, vi nhiu ph

thuc gia cc b phn ca h thng m khng c hiu r. Thuc tnh h thng tng

th ni ln nh kt qu ca nhiu k s phn mm thit k cho cc mnh nh ca h thng

m khng c khun kh cu trc c cung cp bi thit k kin trc s khng c hiu

r mi cho ti khi h thng c thc hin. Kin trc cung cp phng tin phn

hoch h thng thnh cc phn t m v sau c th c thit k chi tit. Kin trc c th

c xem xt k lng v kho cu phi by ra nhng nhc im trc khi thit k

phn t chi tit v thc hin. Cui cng, kin trc c th c dng hng dn tng

th vic xy dng bng vic phc v nh iu bt buc v cch cc phn t c th c

lp rp, lm ny sinh ra trong h thng vi nhng thuc tnh v hnh vi d on c.

Thit k kin trc khc vi thit k phn mm chi tit di dng mi quan tm c

cp, nh:

Thit k kin trc cp ti vic phn hoch h thng thnh cc b phn hay phn t v tng tc gia cc phn t ny, trong khi thit k chi tit cp ti chi tit

thc hin ca cc b phn ny. Kin trc s hi t vo cc thuc tnh bn ngoi

ca cc phn t, tng th cc phn t, v cu trc h thng, trong khi thit k chi

tit hi t vo phn ni b ca cc phn t, cu trc d liu, v thut ton c

dng bn trong mt phn t. Thc ra, tng tc bn ngoi c th b che giu vi

ngi thit k. Kin trc khng thay th cho thit k chi tit nhng thay v th b

sung cho n bng vic to khung cho cng vic ca ngi thit k pha h lu v

ngi thc hin v hng dn tch hp cc phn t thnh h thng.

Thit k kin trc cp ti thuc tnh tng th ca h thng nh hiu nng, tnh sa i c, tnh an ninh, v cc thuc tnh khc bn cnh chc nng chung.

Thit k chi tit lin quan ti thuc tnh tnh ton chuyn mn v chc nng c

cung cp bi tng phn t ring.

Thit k kin trc mang tnh khai bo. Kin trc s phn hoch, thit k v lm ti liu cc phn t h thng da trn ch yu l trc gic v kinh nghim bi v mt

ngn ng c t kin trc chnh thc, chun ho, bao hm tt c vn l iu gy

hng khi hn l thc ti. Qu vy, mc ch chnh ca cun sch ny l lm

du v hng dn trc gic kh kim ca kin trc s bng cc nguyn l thit k.

Vi trng thi hin thi ca thc hnh, khng c "trnh bin dch kin trc"

kim vn phm v ng ngha ca thit k kin trc. Thit k chi tit l mang bn

tnh vn hnh trong chng c ng c dch trc tip thnh m, trong khi

thit k kin trc c ng to khun kh cho cng vic ca nhng ngi thit

k chi tit.

Thit k kin trc c yu cu cp ti vn v qui m v do l khc bit

nn tng vi cc biu lp phn mm v s cu trc. Kh v mt tr tu xy dng

cc h thng ln mt cch trc tip bng vic hi t vo cu trc chi tit m khng c

thit k kin trc cung cp bn l trnh cho nhng ngi thit k chi tit v ngi thc

hin. Trong khi c th rt d dng xy dng cc ng dng nh ng ring r vi vi ngi

6

lin quan v doanh nghip khng quan tm ti kin trc v rt t quan tm ti thit k chi

tit, cch tip cn ny khng i qui m c tht tt.

Xy dng h thng ln phc tp dng nhiu phn mm vi nhiu ngi c lin

quan cnh tranh nhau v mi quan tm ca doanh nghip l mt ngh rt khc, yu cu

cc tng tru tng thit k c iu phi hng dn thc hin. Rt kh lun gii v

vic tho mn cc thuc tnh h thng rng trong h thng c nhiu ngi pht trin,

nhiu khch hng, nhiu ngi dng, v nhng ngi c lin quan khc m khng c thit

k kin trc bc cu gia cc yu cu h thng v thit k phn mm chi tit. Kin trc

phn mm c th gip cc k s nhn din, xc nh, v phn tch mt cch h thng cho

cc yu cu v h thng ln trc khi thit k chi tit v xy dng cc phn t h thng

bt u.

Vng i kin trc

Thut ng qui trnh phn mm c dng m t qui cch pht trin phn mm

trong t chc. Qui trnh phn mm ca t chc m t tin iu kin, hu iu kin, hot

ng, vt phm, vai tr v vn vn c mi ngi trong t chc dng pht trin phn

mm. iu chng ta thy trong thc hnh l ch qui trnh phn mm ca t chc bao

gm nhiu qui trnh nh hn cp ti cc chc nng t chc then cht nh qun l cu

hnh, yu cu, kim th, m bo cht lng, c lng, truy nguyn d n, vn vn.

Khng may trong thc t, thit k l thnh vin khng c phc v ng mc nht ca

tp cc qui trnh ny. Cng ng ci tin qui trnh cp ti cc mi quan tm t k thut

v cch phn mm c thit k di dng thu thp yu cu, phn tch, qun l cu hnh,

kim th, v m bo cht lng. Trong khi cc nh ngha qui trnh t chc bao gm cc

vt phm t qui trnh thit k, qui trnh thit k thng khng c cho cng mc ch

nh cc qui trnh t chc khc. Thit k kin trc thng c i x nh ct mc c

o bi s hin din ca vt phm. Thit k l qui trnh k thut duy nht yu cu nhiu ch

nh bt k hot ng no trong cc hot ng ny, nhng him khi nhn c s ch

. Ch trung tm ca cun sch ny l ch thit k l qui trnh, khng ch l vt

phm hay ct mc (Hnh 1.1). Thit k l qui trnh k thut cn c thit lp v nh

ngha, cng nh bt k qui trnh no khc trong t chc.

Hnh 1.1 Cc hot ng then cht ca qui trnh thit k.

Thm d

phng n:

To ra thit k

khi u

Ci tin: Dng

kt qu ca

nh gi

ci tin thit k

Hu sn xut:

Sa, Nng cao,

i,

Phn r

Chng ct

yu cu thnh

dn li kin

trc

Drivers

nh gi thit

k: m bo

thit k p

ng nhu cu

Needs

Sn xut:

m bo tun

th theo

thit k

7

Hnh 1.2 m t vng i t nhin ca thit k kin trc quanh t chc nn ngh

v vic thit lp cc qui trnh thit k ca h (chng ti s a vo mt qui trnh thit k

kin trc chuyn mn v sau). Vng i kin trc v nn tng bt u vi hon cnh

doanh nghip v nhng ngi c lin quan h thng. Th trng, cu trc t chc, ngn

sch, lch biu, cng ngh sn c, v vn vn t hon cnh doanh nghip m trong h

thng c xy dng. Thut ng ngi c lin quan - stakeholders - c dng y (v

trong ton b cun sch ny) ni ti cng ng rng hn l ngi dng. Nh Hnh 1.2

minh ho, nhng ngi c lin quan cung cp tp cc iu mun v cn phi cu trc bn

trong hon cnh m phi c t chc trong cc dn li kin trc. Bi v dn li kin trc

l yu cu mu cht hnh thnh nn thit k ca kin trc, s tham gia ca nhng ngi

c lin quan rng l cn thit trong vic nhn din v nh lng ca h. iu mu cht l

kin trc l mt phn ca qui trnh nhn din v cu trc cc dn li kin trc. Nh chng

ta s thy, dn li kin trc l nhng yu cu chc nng th, nhng rng buc v yu cu

thuc tnh cht lng. Dn li kin trc khng phi l tt c yu cu cho h thng, nhng

nhng dn li kin trc s nh hng ti cu trc m kin trc s la chn v ngi

thit k ra kin trc. Mt khi c thit lp, dn li kin trc s p t lc thit k ln cc

kin trc s, iu nh hng ti la chn ca h v cu trc. p ng vi cc lc thit k,

kin trc s la chn v thit k tp cc cu trc tho mn chng.

Hnh 1.2 Vng i kin trc.

Trong khi ch ca cun sch ny l v kin trc v thit k, ng bt k ai la

bn: n cui cng, thc hin mi l vn ! Khch hng mua sn phm, khng mua kin

trc, qui trnh, ch to vn vn. Khch hng nh gi v la chn sn phm da trn cc

tnh nng chng c hay khng c. Khch hng t gi tr vo sn phm da trn chi ph,

8

cht lng, chc nng v gi tr c cm nhn ca sn phm. Tuy nhin, m l khng

. D c thit k c ch hay khng, mi h thng dng nhiu phn mm u c kin

trc, v cc sn phm u ri rc cc kin trc, d chng ta c nh v chng hay khng,

vi mi im mnh v im yu ca chng. Mc du khng thy c trc tip vi khch

hng, cht lng ca kin trc ca sn phm tc ng su sc ti tnh nng ca vt chuyn

giao, thuc tnh, cht lng c cm nhn, v gi tr ca sn phm hm nay v ngy

mai. Nu sn phm khng p ng mong i ca ngi lin quan v li thit k, ngi

c th khng dng sn phm hay dch v ca bn xem nh kt qu. Cho nn trong khi i

a s nhng ngi c lin quan khng chm nom trc tip v kin trc, thit k kin trc

vn l quan trng mu cht trong vic p ng nhu cu ca h hm nay v ngy mai.

iu ny ngha l bn phi chm nom v thit k kin trc, d cho khch hng, ngi

dng, hay nhng ngi c lin quan tng t khc khng chm nom v n.

Kin trc s ng vai tr sng cn trong ton th vng i sn phm, khng ch

trong thit k kin trc khi u. Mt khi kin trc c thit k bi kin trc s, h

thng c th c thc hin. Ti im ny, kin trc s phi hng dn nhng ngi thit

k v pht trin pha h lu trong xy dng m bo rng vic thc hin snh ng

theo thit k kin trc. y l mt trong nhng vai tr mu cht nht m kin trc s gi

trong pht trin h thng. Nu cu trc thc hin khng snh ng theo cu trc thit k,

th bt k ha hn no c lm tng ng theo thit k kin trc c th khng c hon

thnh bi vic thc hin. Mt khi c thc hin v trin khai, vng i kin trc ni

chung tun theo con ng ca hn n, ph bin, ph bin, chp thun, thu hoch, v x

tn. Kin trc s ng vai tr mu cht trong vng i ny.

Hn n

Trong thi k hn n, cc nh cung cp a dng cnh tranh cng mt khng gian

th trng. Nhng ngi c trang b tt nht khai thc kin trc c u th t nhin

hn so vi cc i th cnh tranh. Th nht khng phi bao gi cng l tt nht, v lch

s c y ry cc v d, nh Minitab, Wordstar, DB, Novel, Mac GUI OS, v nhng th

khc. Mt sn phm mi a vo vi kin trc km c th y t chc vo th yu ni n

phi ci t ng k cho ln a ra sau. y thng thng l vn tn tht tr phi bn

c ti tr tt - xt Microsoft v Windows 95. Vic chuyn i l au n v tn km,

nhng cho h vo v th tt hn duy tr th ca h trn th trng h iu hnh.

Kin trc tt hn thng thng trong ng trng. T hn n nhng ngi lnh o

ni ln v mt mt s i th cnh tranh cht hay t gt mnh khi vic cnh tranh.

Ph bin

Mt khi mt ngi lnh o ni ln, nhng ngi khc theo sau bi v h thy li

nhun trong kin trc ca ngi lnh o. Nhng ngi chp nhn sm s i theo sn

phm ny v kin trc nn. Kin trc m m th trng c dn li thng c c vic

ph bin rng nht thay v nhng kin trc c hnh thnh qua tho hip v bt buc ca

cc c quan tiu chun. Mt s sn phm dng nh l lnh o, b vt qua v ngi ta

khng bao gi nhn ra vic ph bin rng v cht ti im ny.

9

Chp nhn

Ti im ny c ngi lnh o r rng trong th trng. N chc chn thit lp

kim sot th trng qua s ng ct yu nhng ngi c lin quan trong vic to ra h

sinh thi kin trc. Chp nhn l c thit lp vng chc khi cc bn khc trong min

nhn vo ngi lnh o v nhng thay i kin trc.

Thu hoch

Trong thu hoch, ngi lnh o tr thnh "ngi ch" ca kin trc v c tha

nhn nh chuyn gia v ngi lnh o. iu h ni v lm lin quan ti m thc kin

trc l nhng li v hnh ng dt khot. Ti im ny ngi lnh o tn hng tnh

sinh li cao t nhiu lung thu nhp. Sn phm v kin trc nn c duy tr v m rng

p ng nhu cu tng khng ngng t mt cng ng nhng ngi c lin quan ang

tng trng.

X tn

Trong thi k x tn, cc cu trc kin trc b xi mn ti im thit k li vic thay

th cn c hiu qu-chi ph hn. Ni chung, kin trc tt hn sng lu hn, nhng khong

sng ca sn phm v kin trc nn tng b nh hng ln bi tnh thay i ca th trng

v cng ngh hn bt k ci g khc. Nu bn xy dng sn phm dng cng ngh tin ho

nhanh chng cho th trng tin ho nhanh chng hn, nn mong i vng i tng i

ngn hn cho sn phm v kin trc nn ca chng. Trong nhng th trng ny, kin trc

c thit k tt hn c th ko di lu hn, nhng cng s mt nhiu thi gian hn, c

th tc ng ln kh nng ca bn chm ti ca s th trng c d on. y l b

tr ti chnh, th trng, v k ngh iu s yu cu nhng ngi tham gia t tng trong

nhng cng ng ny ti u thi gian m c th v nn c dnh cho thit k kin

trc.

Trong thi k x tn, nhng ngi lnh o ang trn s vic tip v nhng ngi

chp nhn sm i theo lnh o ca h. Nu nhng ngi lnh o khng i tip, h c

nguy c mt th lnh o ca h. IBM gn nh chu ng s mnh ny vo nhng nm

1980 khi n khng nhn ra thay i trong cc lc th trng t my tnh ln chuyn sang

my tnh bn. May mn d tr tin mt ca n cho php n pht minh li m hinh kinh

doanh ca n v sng tip. Cc cng ti khc, nh Digital Equipment Corporation (DEC),

Control Data Corporation (CDC), v Sperry UNIVAC, khng may mn c nh vy.

Trong thi k x tn, nhng ngi n theo ni ln trong th trng duy tr ca tha t

v c th tr thnh kinh doanh sinh li vi vic gi cn bng ng ca cung (nhng ngi

n theo h tr cho tha t) v nhu cu (ngi dng tha t).

C kin trc s hay t kin trc trong hi ho vi vng i kin trc v nhu cu

kinh doanh v mc ch t chc l mu cht cho tnh cnh tranh ca t chc. iu ny l

ng ch yu bi v tin b qua vng i kin trc bao gi cng c ngha l thit k kin

trc nguyn thu phi tin ho, v kin trc s ng vai tr nng ct trong thit k h

thng m c th tin ho v trong qun l tin ho ca sn phm qua kin trc.

Nh Hnh 1.2 minh ho, mt khi c thc hin v trin khai, h thng s bt u

nh hng ti chnh nhng ngi c lin quan m c nh hng ti thit k nguyn thu

ca h thng ngay ch u tin. Rng hn, kin trc b nh hng bi a dng cc lc bn

ngoi. iu thng thng l nghe li ku than ca kin trc s v k s lin quan ti thay

10

i yu cu; tuy nhin, chng ta c th d ng hn l phn ng vi yu cu thay i. Cc

yu t m c th dn ti thay i trong Thit k kin trc v vng i kin trc c th

cung cp ci nhn sng sut vo trong cc yu t ny, iu c th a ti nhng thay i

trong yu cu. Hnh 1.3 minh ho cc yu t then cht nh hng vo hon cnh doanh

nghip v do ti dn li kin trc. Mt khi c trin khai, thit k kin trc b tc

ng bi nhng thay i trong nhng ngi lin quan, m hnh doanh nghip, th trng,

cng ngh, v cu trc t chc.

Nhng ngi c lin quan

Trong vng i kin trc nhng ngi c lin quan c th ti ri i. Thng chng

ta tr thnh nn nhn ca thnh cng ca h thng ca chng ta. Nhng ngi c lin

quan mi s c nhu cu hi khc i so vi nhng ngi c lin quan gc, c th thch ng

sn phm ca chng ta. Khi nhng ngi c lin quan ra i, mt s dn li kin trc c

th khng cn hp thc v nhng ngi ti tr mi em ti nhng mong i mi vo

trong khng gian thit k. Kin trc s cn ch ti vic rt xung v lung chy ca

nhng ngi c lin trong hon cnh h thng v nh gi tc ng ca s hin din hay

vng mt ca h ln dn li kin trc.

Hnh 1.3 nh hng bn ngoi ca vng i kin trc.

Nhng ngi c lin quan

M hnh doanh nghip

Th trng

Cng ngh

Cu trc t chc

11

M hnh doanh nghip

M hnh doanh nghip l nhng vn hnh ti chnh v doanh nghip trong h

thng c thit k v xy dng. V d v m hnh doanh nghip c th bao gm:

M hnh ti chnh cho tip th, bn, v phn phi ca h thng

Qui trnh v vn hnh doanh nghip c h thng thc hin

Nhng thu xp doanh nghip v ti chnh c thc hin vi nh cung cp

M hnh doanh nghip c th l ni b hay bn ngoi vi mt t chc. Sau khi h

thng c trin khai, m hnh doanh nghip tin ho, v nhng m hnh doanh nghip

to ng c cho cc quyt nh thit k nguyn thu c th khng cn hp thc na. Khi

m hnh doanh nghip bn trong hay bn ngoi tin ho, bn c th th trc thay i cho

dn li kin trc.

Th trng

Th trng l ni sn phm cung cp gi tr v bt u cung cp tin thu hi theo

u t. Th trng thay i v tin ho khng ngng, v iu bn cht l chng ta khng

ch tng tc vi nhng thay i trong th trng m cn nhn din d ng nhng thay

i v c hi tim nng cho sn phm ca chng ta. Mt s th trng l linh ng hn

cc th trng khc, v tnh linh ng ny s c phn nh vo thit k ca chng ta.

Trong mt v d cc oan, th trng in thoi di ng l linh ng cao , v t chc l

s mt trong th trng ny vi nhng tnh nng mi nht s thng mt ngy no . Sau

khi chuyn giao sn phm khi u, gi cho in thoi di ng st ln qua ca s ngn

18-thng. iu ny to ra kt qu trong vng i kin trc l ngn v no nhit. Ly v d

khc, xt ng dng Internet n-bn nh h thng im bn hng, qun l quan h khch

hng, vn vn. Th trng cho nhng h thng ny l tng i n nh v m hnh vn

hnh tng qut c thit lp tt trong nhiu nm ti gi. Trong hu ht cc trng

hp, mt khi c trin khai, cu trc li ca nhng h thng ny vn cn tng i

khng thay i cho d cc tnh nng v chc nng c th c thm vo v thay i qua

vng i kin trc. Thng nhng h thng ny phi i qui m theo cc cch a dng

p ng cho nhu cu th trng tng trng. Khi th trng tin ho v thay i, phi

mong i nhng thay i cho dn li kin trc.

Mi trng cng ngh

V nn tng, h thng dng nhiu phn mm tu thuc vo cng ngh, cho nn iu

ng ngc nhin l kin trc s li khng d ng nhiu v nhn ln pha trc vo cnh

quan cng ngh tin ho nhn din cng ngh mi ni ln, ci gy ra thay i yu cu.

Trong mt s hon cnh h thng, iu c ngha l bao qut c cng ngh mi nhn nhiu

ri ro hn c tnh cnh tranh hn. Trong nhng trng hp khc, iu ny c th l

thm ho - ci mi hn khng phi bao gi cng tt hn. Chng hn, trong th trng in

t tiu th nhu cu v tnh nng mi thng dn li ngi pht trin sn phm ti gi nh

v pht trin hay thch nghi cng ngh mi nht v gn nht sn c. Tuy nhin, trong

min h thng kim sot hng khng, cng ngh mi c tnh ri ro khng phi l tng

tt cho khu vc hng khng thng mi. Nhng h thng ny phi cc k tin cy, cho nn

12

cc cng ngh v phng php lun c chng minh mi l n hng ca hm nay.

Tin ho cng ngh trong min hng khng (hay cc min tng t) l chm hn mt

cch cn thit v c ch nh hn th trng in t tiu th. Tuy nhin, trong c hai

trng hp thay i cng ngh u l khng trnh khi. Bn ngoi nhp ca chp nhn,

cng ngh mi nm trung tm vic lm cho n tt hn, nhanh hn v r hn. Kin trc

s cn ch ti cng ngh ang ni ln nh gi tc ng ca n ln h thng, thit k

ca h v cui cng ln dn li kin trc.

Cu trc t chc

H thng c xy dng trong cc t chc con ngi. Mt khi h thng c thit

k, cc t chc ni ln quanh cu trc ca h thng. Theo ngha rt thc, thit k k thut

lm cho t chc tt hn hay ti hn. Bi v s kin ny, thay i trong cu trc t chc

thng c th gy ra thay i cho dn li kin trc. Kh b hay b sung cc t chc c h

tr h thng hay cc phn t ca h thng c th c tc dng rt thc ln cu trc ca h

thng c xy dng hay trong qu trnh ang c xy dng. Tng t, nu chng ta

nh thay i cu trc kin trc theo cch trit , iu ny c th tc ng ln cu trc t

chc hin c. Cu trc t chc c th l ni b hay bn ngoi cho t chc sn xut. Thay

i trong cu trc t chc ca nh cung cp c th tc ng ln cu trc ca h thng su

sc nh thay i trong cu trc t chc ni b. Xt v d trong Hnh 1.4.

Hnh 1.4 Thit k h thng khi u v quan h ca n vi cu trc t chc.

V d ny ti t kinh nghim thc t ni h thng c xy dng vo thi im A.

H thng bao gm ba phn t then cht: b x l vo, qui trnh hin th, v b x l lch

13

s. Tng phn t ny u l my tnh mini c tp cc ng dng. Nhng h thng ny

c ni bi ng bus b nh dng chung tc cao. Mt lc lng lao ng xut hin

quanh thit k ny h tr cho tng phn t ny. Lc lng lao ng ln nht c cn

h tr cho b x l hin th phc tp v dy cc trc quan d liu ca n v ng dng

phn tch. Tuy nhin, sau nm nm s dng thnh cng, h thng c d nh thit k li

v c thay th bng mt h thng th h mi c nhiu nng lc hn. Bi v tin b

cng ngh, c th xy dng h thng mi ch vi b x l ci vo v b x l lch s. C

nhng my tnh mnh hn, r hn, nh hn rt ng k. Trong thit k h thng mi, b

x l hin th c thay th bng trm lm vic v b nh dng chung c thay th bng

mng tc cao. Hnh 1.5 minh ho h thng th h mi ny.

Hnh 1.5 Thit k h thng sinh th hai v tc ng ca n ln cu trc t chc.

H thng ny l ci tin ln lao so vi h thng c theo nhiu cch. N nhanh hn,

r hn trong xy dng, tin cy hn, v c kh nng x l nhiu d liu. C v l tng

hay, ngoi tr rng vi thit k h thng th h th hai lc lng lao ng tha t

khng ging thng vi kin trc c ngh. Ch mt phn ca nhm hin th nguyn

gc c cn h tr cho h thng mi. T h tr cho truy nhp b nh dng chung v

ng dng khng cn c cn ti cht no, v cn t nhn s hn duy tr b x l lch

s v thu nhn. iu ny a ra nhiu kinh hong trong lc lng lao ng tha t v

thit k mi, trong khi v mt cng ngh l tt hn, l thch thc cho t chc thch

ng v dch chuyn sang. Tng t, nu thay i t chc xut hin, chng c th tc ng

ti kh nng h tr, duy tr, hay lm tin ho h thng qua thi gian. Kin trc s phi

ch cht ch ti cu trc t chc v mi quan h ca chng thit k thay i cu trc

m trong c th tc ng su sc ln dn li doanh nghip.

Vng i kin trc c th v nn c phn tch nh mt phn ca chin lc qun

l cng ngh. Thay i vi h thng phi c nh gi bi kin trc s xc nh tc

ng ln thuc tnh h thng hin thi v xc nh cch thc hin v tch hp tt nht th

no cho thay i vi h thng. Vng i kin trc tip tc cho ti khi kin trc xi mn

ti im khng cn kh nng iu chnh theo thay i hay khng duy tr c hiu qu-

14

chi ph. Thnh thong vng i kin trc l tng i ngn (mt ti ba nm) v thnh

thong tng i di (hng thp k). Trong c hai trng hp, cc t chc phi hiu hon

cnh doanh nghip h phi vn hnh, pht minh ra chin lc kin trc thch hp, v qun

l d ng cho vng i kin trc.

Ch , mc ch v t chc

Ch then cht nn tng cho cun sch ny l ch u tin v trn ht, thit k

kin trc l n lc k thut yu cu trc gic v nguyn l. Th hai, cc hot ng thit k

phi c t chc v c xc nh bi t chc gim chi ph thit k v thi gian mt

cho thit k, v tng tnh d on c v gi tr ca qui trnh thit k. Mc ch ca cun

sch ny l cung cp cho cc k s thc hnh chu trch nhim cho thit k h thng

dng nhiu phn mm vi:

Bi cnh trong nguyn l thit k kin trc

Hng dn v cch thit k kin trc cho thit k h thng dng nhiu phn mm

Phng php thit k ly kin trc lm trng tm c th gip cho cc t chc tch hp d dng hn cc qui trnh thit k kin trc lp li c v c k lut vo trong qui

trnh pht trin phn mm ca t chc

Hng dn thc hnh cho chuyn i sang thc hnh thit k kin trc c nhiu k lut hn

Ti nhng im cui ny, cun sch c t chc thnh ba phn chung, nh sau.

Phn 1: Nguyn l kin trc

Phn ny gii thiu cc khi nim v nguyn l kin trc c s m l bn cht cho

cc ch cn li c trnh by trong cun sch. Phn ny bao gm cc ch sau:

Thut ng kin trc c nh ngha r rng hn, v ni ring, thit k kin trc phn mm c nh ngha r. H thng, doanh nghip, v mi quan tm thit k kin trc

phn mm c phn bit, v thut ng c dng trong ton b cun sch c nh

ngha.

Nhng yu cu a ti thit k kin trc c thm d, v cc phng php nm bt v phn tch chng c trnh by.

Cu trc ca h thng dng nhiu phn mm v hiu qu ca chng ln thuc tnh h thng c tho lun chi tit.

Dng cc nguyn l thit k c nu i cng ti gi, hng dn cho hot ng thit k v cng c qua cc v d.

Cc chin lc lm ti liu kin trc phn mm c tho lun.

15

Phn 2: Qui trnh thit k kin trc

Trong phn ny, cc nguyn l ca Phn 1 c a vo thc hnh bn trong khun

kh thit k phng php lun m c th c dng khi u qui trnh thit k trong t

chc. Ch ca Phn 2 l ch thit k kin trc ca h thng dng nhiu phn mm l

qui trnh k thut, khng phi l bin c hay ct mc c o ch bi s hin din hay

vng mt ca vt phm. Phng php thit k ly kin trc lm trng tm (ACDM) c

gii thiu, chnh l chin lc cho thu thp yu cu kin trc, t chc v phn tch chng,

thit k kin trc, nh gi kin trc, v ci tin n theo cch lp li. Cc bc c bit

ca phng php ny c m t trong ton b phn ny. Ci vo v ci ra tng giai

on c m t, v cc khun mu a dng cng cc v d c cung cp. Phn ny

cng tho lun nhng cch thc m kin trc c th c dng ging thng lc lng

lao ng, cung cp ci nhn su cho c lng d n, gip trong theo di v gim st, v

cp ti cc mi quan tm vn khc.

Phn 3: i qui m v tch hp ACDM vi khun kh qui trnh hin c

Phn cui cng m t cch ACDM c th c i qui m theo cc d n ln hn

v c dng vi cc khun kh qui trnh pht trin a dng. Cc khun kh sau y

c cp ti:

Qui trnh thc chung

Qui trnh Phn mm T - Team Software Process (Thng hiu ng k ca Vin k ngh phn mm, Pittsburgh, Pennsylvania)

Rational Unified Process (Thng hiu ng k ca International Business Machine, Inc.)

Scrum (Schwaber v Beedle, 2004)

Lp trnh cc oan (Beck, 2000)

M hnh trng thnh nng lc tch hp - Capability Maturity Model Integrated (Thng hiu ng k ca Vin k ngh phn mm, Pittsburgh,

Pennsylvania)

Vi tng trong nhng khun kh qui trnh ny, khun kh c bn s c m t v

cch n cp ti thit k kin trc. Khuyn co s c cung cp m t cho cch an dt

ACDM v thc hnh thit k kin trc chung thnh khun kh cp ti mi quan tm

kin trc hiu qu hn. Bn cnh nhng khun kh qui trnh ny, phn ny cng s tho

lun khu vc qui trnh no ca M hnh trng thnh nng lc tch hp c th c

cp ti bng vic dng ACDM.

16

Chng 2 Kin trc c nh ngha

Kin trc l m nhc b ng cng.

John Bartlett (18201905)

tng rng h thng khng c to nn bi cc my mc ring l m l tp hp

phn b cc phn t c mi quan h phc tp, lm nn tng cho l thuyt v thc hnh k

ngh hin i nht ngy nay. Trong 50 nm qua vai tr ca phn mm trong cc h thng

hin i tng ln v tm quan trng. Nh mt phn t h thng, phn mm to kh

nng cho ngi thit k xy dng nhng h thng thng minh, c nng lc, linh hot hn.

Ngy nay phn mm trn ngp trong cc h thng hin i v c th c tm thy trong

my nh v ng h, my bay v con tu v tr, t, h thng y t, v mt v tr cc h

thng CNTT bn cht cho vn hnh ca kinh doanh o, doanh nghip ton cu, v cc

chnh ph. Tuy nhin, trong khi phn mm c kh nng to ra cc h thng linh hot v

c nng lc, n lm phc tp hn vic xy dng, trin khai, bo tr, v vn hnh ca h

thng hin i dng nhiu phn mm. a dng thit k, ti liu, v phng php k php

c pht trin qua nhiu nm m t cho thit k h thng dng nhiu phn mm v

gip cho cc k s phn tch cc tnh cht ca nhng h thng ny. Thut ng kin trc h

thng, kin trc s nghip, v kin trc phn mm thng c dng ngy nay m t

cho thit k th v cc cu trc nn ca tp hp phc tp cc phn t bao gm h thng,

s nghip v ng dng phn mm phc tp ln. Tuy nhin, trong nhng nm gn u

thut ng kin trc tr thnh b qu ti nng. Khng may, khng c chun, khng c

cc nh ngha c chp nhn rng ri v kin trc h thng, s nghip, v phn mm,

mc du nhiu khi nim nm di nhng thut ng ny l c lin quan cht ch.

Kin trc nh mt khi nim thit k c qung t nht t thi Ai Cp c i, vi

thit k v xy dng cc kim t thp. Vic dng thut ng kin trc m t cc thit k

ch c ng ca con ngi t nht cng sm t ngay th k th nht trc cng nguyn, khi

kin trc s li lc ngi La M Vitruvius dng thut ng ny m t cc nguyn l c

bn ca thit k kin trc. Chuyn lun ca cng trnh ca ng y c cn c vo ba

phm cht then cht hnh thnh nn c s ca nguyn l thit k. Vitruvius (1914, Tp

I, Chng 2, trang 13) vit Kin trc ph thuc vo trt t, thu xp, cn i, i xng,

thuc tnh v kinh t. ng y bin lun rng kin trc v cu trc kt qu phi tho mn

tnh dng c c d nh ca chng, phi hon chnh v mt vt l, v phi truyn t

ngha thm m. ng y cng ch ra rng thit k kin trc tt nht s ny sinh trong vic

cc to nh tn ti lu hn vic dng nguyn gc ca chng - mt mc ch rt quan trng

17

trong thit k ca h thng dng nhiu phn mm. Chuyn lun ca ng y nh du ln

u tin rng cc nguyn l thit k kin trc c lm ti liu trong n lc h thng

ho cc nguyn l cho kin trc s. T thut ng ny ln u tin xut hin trong sch

v La M, khi nim thit k kin trc c p dng rng ri cho nhiu min. Thut

ng kin trc cnh tr c dng trong cun sch c Gilbert Laing Meason xut bn

nm 1828 v c th l vic dng u tin ca kin trc ni ti thit k ci g khc

hn to nh. Ngy nay t in ting Anh Oxford c mt nh ngha rt rng v kin trc

bao gm nhiu iu hn thit k truyn thng v cu trc to nh, chng hn:

Hnh ng: hnh ng hay qui trnh xy dng

Vt phm: Thit k, cu trc, to nh

Quan nim: Cu trc quan nim v t chc logic tng th ca my tnh hay h thng da trn my tnh theo quan im ca vic dng n hay thit k

Ngy nay thut ng kin trc thng c dng ch thit k cc thit b k thut.

Trong hon cnh ny, kin trc v nn tng l v thit k cc cu trc th hay cc b phn

m bao gm sn phm, thit b, h thng vn vn. Kin trc s phn r h thng, s

nghip, hay phn mm thnh cc phn t theo cch khai bo, c hng dn ch yu bi

trc gic v kinh nghim. Thit k kin trc mang tnh khai bo theo ngha kin trc s

tuyn b cc b phn hay phn t ca h thng l g, thuc tnh v giao din ca chng,

v cch cc phn t ny quan h vi nhau. Khi c thit k, pht trin, v tch hp,

nhng b phn to ra mt tp hp lm vic cng nhau cung cp dch v no ln

hn bt k tng b phn no ring n. Bi v thit k kin trc mang tnh khai bo, d

dng thc hin mt cch lm ln. Tuy nhin, kh lm cho n ng, kh lm tt, v ht sc

d dng phm sai lm. Nhng chn la sm m kin trc s thc hin c tc ng su,

ko di ln sn phm v t chc. Nu chn la sai c lm sm, th c th khng th no

hon tc chng v sau. Trong khi kin trc c thit k, khng phi mi thit k u c

tnh kin trc v bn cht. Thit k kin trc b qua thit k ni b chi tit bn trong ca

cc phn t ca phn r. Thit k chi tit cho nhng phn t ny c tr cho nhng

ngi thit k pha h lu, ngi hi t vo cc chi tit v cch cc phn t ny cung cp

dch v m kin trc s khai bo rng chng s cung cp.

Mt cm nhn sai thng thng l ch kin trc ch l cc hnh nh - hnh nh

khng phi l kin trc. Cc biu din kin trc l nhng bc nh n thun v cu trc

ang tn ti hay nhng cu trc s c xy dng. Tuy nhin, h thng dng nhiu phn

mm c nhng cu trc thc c hnh thnh t cc phn t v mi quan h gia chng -

v y l kin trc thc. T lu trc khi vic xy dng v cc cu trc thc c xy

dng, biu din thit k phc v nh c s h tr cho phn tch tp ln hn cc phn

t. Mc ch ti thng ca phn tch thit k kin trc l m bo rng h thng c

thc hin chuyn giao dch v v c cc thuc tnh c yu cu. H thng dng nhiu

phn mm l a chiu trong tnh thy c ca cu trc h thng v mt tnh khng

phi l cng cu trc thy c vo lc chy, v vn c nhiu cu trc vt l hn l thy

c na. Bi v h thng dng nhiu phn mm l a chiu, kin trc s phi ngh theo

ba chiu, v biu din thit k kin trc phi l a chiu biu din nhiu cu trc v cc

th c xy dng. Chng hn, biu din thch hp mt ngi nh hin i chng ta s

cn mt biu din m t cho cu trc to nh, mt biu din khc cho h thng in, v

mt biu din khc na cho ng nc. Tng cu trc ny l hon ton thc, v c

gn li vi nhau chng hp thnh mt tng th cc phn t m l ngi nh. Chng ta

c th dng nhng cch nhn a dng ny thuyt phc v cc thuc tnh m ch c ng

s c khi c xy dng: N c ln khng? N c sng khng? N c nng

lng khng?

18

Ngi ta c th d dng i t phng n sang phng kia theo hnh mu lung c

mong i khng? Ti c th thay i hay thm ch c khng? Ti c th sa cha n

c khng? Cng iu ny l ng cho h thng dng nhiu phn mm. Biu din thit

k kin trc l nhng hnh nh ca cc cu trc m s c, hay ang c, hin din trong

thc hin. Ging nh v d v ngi nh ni trn, h thng dng nhiu phn mm yu cu

nhiu biu din t cc cnh quan a dng m t h thng. c gn vi nhau, nhng

biu din ny cho php nhng ngi c lin quan trao i v h thng, thuyt phc v cc

thuc tnh n c v khng c, v hng dn thit k chi tit v xy dng.

Thit k kin trc c th cung cp ci nhn su bn cht cho cc k s khi thit k h

thng dng nhiu phn mm. Cng nh trong v d kin trc to nh trc, cc thit k

kin trc ny nhn din cc b phn ca h thng, s nghip, hay phn mm, v cch

chng s tng tc to ra dch v. Biu din thit k c th c dng phn tch

hnh vi tng th v cc thuc tnh phi hnh vi ca h thng, s nghip, hay phn mm.

Thuc tnh hnh vi bao gm cc yu cu chc nng bn cht, trong khi cc thuc tnh phi

hnh vi bao gm hiu nng, tnh sa i c, tnh lin tc, v tnh an ninh, trong cc th

khc. Trong cun sch ny, cc thuc tnh phi hnh vi s c ni ti nh cc c tnh

cht lng (Bass et al., 2002). Nhng ngi thit k h thng, s nghip, v phn mm

phi lin tc lm nhng b tr gia cc yu cu hnh vi v c tnh cht lng t ti

cn bng chp nhn c cho cng ng nhng ngi c lin quan. Chng hn, mt s

quyt nh thit k kin trc c th thc y thng lng d liu (hiu nng) nhng ph

hoi ngm kh nng thay i h thng (tnh sa i c). Kin trc cho php nhng

ngi thit k nhn din v thuyt phc v nhng b tr ny sm trong vic pht trin

cho nhng thuc tnh ny c th c thit k trong h thng, thay v sa, iu chnh hay

ci t sau pht trin.

Mc du thut ng kin trc h thng, s nghip, v phn mm l mt phn ca t

vng ca cc k s ngy nay, nhng cng ng ny him khi ng v cc nh ngha

chnh xc cho nhng khi nim ny. Hn na, trch nhim v ai to ra chng, chng c

dng lm g, v chng c vit ra th no him khi c xc nh r trong t chc ngy

nay. Thng xuyn cc khc bit gia kin trc h thng, doanh nghip, v phn mm l

ch cho nhng tranh ci nng bng gia cc k s. Cc t chc v k s trong cc cng

ng ny c cam kt tr tu v u t tin bc vo kin trc h thng, doanh nghip v

phn mm ca h, ni c ba nhm ny u c tho thun v lm vic cng nhau mt cch

cng sinh trong nguyn l v trong thc hnh. Xem nh kt qu, nhiu quan nim sai, nh

kin, v mong i khng hin thc pht trin trong nhng cng ng ny. lm sng

t cc thut ng ny, chng ta s trnh by v tho lun v cc nh ngha c dng

chung v kin trc t cc cng ng k ngh h thng, s nghip v phn mm, iu c

ch l hiu c lch s, trng thi