giao trinh software testing bai 2 2536

BI 2. QUY TRNH PHT TRIN PHN MMNi dung:2.1. Quy trnh pht trin phn mm 2.2. Thc trng ca qu trnh pht trin phn mm 2.3. Qu trnh nghin cu c t phn mm

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2.1. QUY TRNH PHT TRIN PHN MMGii thiu: Ni dung:2.1.1. Cc thnh phn ca phn mm 2.1.2. Nhn lc ca mt d n 2.1.3. M hnh pht trin phn mm

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2.1.1. THNH PHN CA PHN MMCc ti liu ca qu trnh

pht trin PM:Yu cu ca khch hng c t sn phm

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2.1.1. THNH PHN CA PHN MMCc ti liu ca qu trnh

pht trin PM:Yu cu ca khch hng c t sn phm K hoch lm vic

Biu Gantt05/26/11 4

2.1.1. THNH PHN CA PHN MMCc ti liu ca qu trnh pht

trin PM:Yu cu ca khch hng c t sn phm K hoch lm vic Ti liu thit k phn mmphn mm nh cng c design Ph thuc vo nhiu yu t Mt s ti liu:05/26/11 5


trin PM:Yu cu ca khch hng c t sn phm K hoch lm vic Ti liu thit k phn mm

Mt s ti liu:Architecture Data flow diagram State transition diagram commented code

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trin PM:Yu cu ca khch hng c t sn phm K hoch lm vic Ti liu thit k phn mm Ti liu kim th

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Test plan Test case list Bug report Test tool

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2.1.1. THNH PHN CA PHN MMCc thnh phn to nn mt

sn phm phn mm:

Help files User's manual Samples and examples Labels and stickers Product support info Icons and art Error messages Ads and marketing material Setup and installation Readme file05/26/11 8

2.1.2. NHN LC CA D NTuy thuc vo cng ty, d n thnh phn ny cn thay i C bn, gm cc thnh phn: Project managers, program managers, hoc producers Architects or system engineers Programmers, developers, or coders Testers hoc Quality Assurance Technical writers, user assistance, user education, manual writers, or

illustrators Configuration management or builder05/26/11 9

2.1.3. M HNH PHT TRIN PHN MMKhng c mt m hnh no l tt nht, ty thuc vo phn mm

la chn m hnh ph hpCc m hnh pht trin phn mm: Big bang Code and fix Waterfall Spiral

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BIG - BANGTun theo hc thuyt to ra v tr t v n Big bang. Tt c

n lc dnh cho vic vit code

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n lc dnh cho vic vit codep dng khi: Spec khng tt Hn hon thnh phn mm n gn Khch hng l nhng ngi d thuyt phc

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n lc dnh cho vic vit codep dng khi: u: rt n gin Nhc: Khch hng khng c bit g v sn phm cho n khi n hon

thnh05/26/11

Sau khi code xong mi din ra qu trnh testing

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CODE AND FIX tng:

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CODE AND FIX tng: p dng: Vi cc d n nh Khi sn phm c tung ra th trng trong mt thi gian ngn

u: - Nhanh, tn t chi ph Nhc: Cha kp test xong version c li update version mi05/26/11

Mt s c trng b b qua => ri ro

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WATERFALL tng: Xc nh r mc tiu ca d n Cc bc tin hnh c lp, khng

c s chng cho Khng c php back up (giai

on trc hon thnh mi c php tin hnh tip giai on sau)

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WATERFALL tng: p dng: M hnh p dng tt vi nhng d n well-understood product Vi mt i project team lm vic rt cht ch v k lut

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WATERFALLu im: y l mt m hnh tng i tng qut Mi th c xc nh cn thn v cht ch Khi bn giao cho cc tester , phn mm kh hon chnh, v s

khng thay i g cho n khi kim th xong => thun li cho cc tester lp k hoch, v thc hin test.

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WATERFALLNhc im: Trong thi i ngy nay, mi th u thay i rt nhanh => Nu

qu cn trng, i khi phn mm s khng theo kp s thay i Khi bn giao cho cc tester , phn mm kh hon chnh =>

nu c mt li xut hin t rt sm, nhng n giai on cui ny mi pht hin => chi ph fix li l rt ln

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WATERFALLCh : Trong thc t: cc dng bin th ca waterfall c p dng

(mt s quy tc c ni lng)

Khng c s chng cho cc giai on C th back up c

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SPIRAL tng: Ra i nm 1986 bi Barry

Boehm Khng xc nh mi th mt

cch chi tit t khi bt u Cc giai on lp i lp li

cho n khi thu c sn phm cui cng05/26/11 21

SPIRALMi ln lp ca Spiral gm 6 bc:1. 2. 3. 4. 5. 6.

Determine objectives, alternatives, and constraints. dentify and resolve risks. Evaluate alternatives. Develop and test the current level. Plan the next level. Decide on the approach for the next level.22

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SPIRALu im: M hnh d hiu v d thc hin C rt nhiu d n thnh cng vi m hnh ny

Nhc im: Spiral khng c phn tch k lng ngay t u nn i khi

h thng c xy dng cha trit i khi kh kim sot k hoch lm vic

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TNG KTBy gi bn phi hiu sn phm phn mm to ra nh th

no, ci g bn trong chng v quy trnh c s dng lin kt chng vi nhau.Ngoi 4 m hnh m t y, cn nhiu m hnh khc na v

bin th ca chng. Mi cng ty, mi d n v mi i s chn m hnh ph hp vi h.Cng vic ca tester l kim tra phn mm n lm vic

tt nht trong m hnh pht trin ca n.05/26/11 24

2.2. THC TRNG CA QU TRNH SOFTWARE TESTINGNi dung:2.2.1. Phng chm ca vic kim th phn mm 2.2.2. nh ngha v thut ng ca qu trnh kim th phn

mm2.2.3. M hnh ch V

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2.2.1. PHNG CHM CA VIC KIM THChn l ca qu trnh kim th phn mm (ST): (rules of the

road hay facts of life)1.

Tester m bo 1 chng trnh l hon ho l iu khng th thc hin c. V:

S lng cc d liu c th l input l rt ln S lng cc d liu c th l output cng v cng ln S lng cc li i (path) trong phn mm l rt ln c t phn mm c tnh cht ch quan. Bn c th ni rng li l nhng khuyt im di con mt ca c gi.

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V d: mt phn mm n gin Microsoft Windows Calculator

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2.2.1. PHNG CHM CA VIC KIM THChn l ca qu trnh kim th phn mm:2.

Testing l 1 bi kim tra ph thuc vo s ri ro Nu khng kim tra ht cc trng hp => s n lc khch hng pht hin ra nhng li b b qun => chi ph khc phc l rt ln

Do vn v thi gian, kinh ph v tnh kh thi => khng th test c ht cc trng hp => ri ro

La chn nhng trng hp test t ri ro nht => u l vn quan trng?

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Testing l 1 bi kim tra ph thuc vo s ri ro Nu c kim tra mi th => chi ph qu ln Nu ct gim cng vic kim th => b qun nhiu li

Vy, phi la chn c cc trng hp kim th ti u => m bo khng phi kim th qu nhiu hay qu t => optimal amount of testing

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Testing khng th tm thy nhng li khng tn ti? Cc hnh thc ca li: ang tn ti (live bug) c sa (dead bug) hoc cn ang tim n (nest) Nu bn c gng kim tra nhng khng tm thy li => khng c ngha l phn mm khng c li => kt lun: li cha c pht hin

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Mt s li c pht hin, t tester suy lun ra mt s li khc: Lp trnh vin cng c lc lm vic tt, cng c lc khng c minh mn

Lp trnh vin cng mc li theo thi quen Tester pht hin ra 1 s li, tng rng chng khng c quan h vi nhau => nhng chng li u xut pht t cng 1 li rt nguy him

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The Pesticide Paradox: Thut ng ny dng m t vic tm li phn mm ging nh vic dng thuc tr su (Pesticide) dit cn trng

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Khng phi tt c cc li m bn pht hin s c sa khng c ngha rng: bn lm sai, hay bn s giao cho khch hng 1 sn phm km cht lng => la chn sa nhng li cha nhiu ri ro nht

Mt s l do khin li khng c fix:

Khng thi gian Khng hn l li C qu nhiu ri ro khi sa li Khng ng phi sa32

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Khng phi tt c cc li m bn pht hin s c sa Nhng ngi a ra quyt nh li no c fix:

Tester project manager Coder V d: Li ca Intel Pentium nm 1994

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Mt vn tn ti nhng khng ai pht hin, hoc khng c ch ti:

C c gi l li khng? Duyt theo 5 quy tc pht hin li Latent bug

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Xy dng spec l cng vic khng bao gi kt thc Mi th lun thay i mau l => Spec cng phi bin i linh hot V d: Cc feature thay i lin tc, khng trong k hoch => bn test xong, v sn sng bo co li, nhng feature li thay i hon ton

Cn c k thut kim th linh hot

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Tester khng phi l thnh vin c coder ch i trong mt d n Nhim v ca 1 tester l g? Tester ph bnh cng vic ca ng nghip, cng khai nhng vn tm thy, c gng chin thng trong cc cuc tranh lun

Tester cn gi thi ha bnh vi ng nghip:Pht hin li tht sm Gi thi hng hi nhit tnh ng ch bo co nhng thng tin xu36

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2.2.1. PHNG CHM CA VIC KIM THChn l ca qu trnh kim th phn mm:10. ST l mt cng vic i hi tnh k lut cao

Tester tr thnh lc lng lng ct, nhng thnh vin sng cn trong nhim v xy dng cc phn mm c cht lng cao

Tester tr thnh mt ngh nghip c nhiu ngi la chn v cn phi c o to

Tester lm vic c k lut v thc y s tin b.

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2.2.2. CC NH NGHA V THUT NG CA STPhn bit cc thut ng:1. 2. 3. 4.

Precision (tp chung) v accuracy (chnh xc) Verification (s kim tra) v Validation (s xc nhn) Quality (cht lng) v reliability (s tin cy) Testing (Kim th) v quality assurance (m bo cht lng) (QA)

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2.2.2. CC NH NGHA V THUT NG CA ST1.

Precision (tp chung) v accuracy (chnh xc):

Hnh trn m t s khc nhau gia 2 thut ng V d: Kim tra yu cu v tnh precision v accuracy trn phn mm Calculator05/26/11 39


Verification (s kim tra) v Validation (s xc nhn):

Vo 4/1990, Knh thin vn khng gian Hubble c a vo qu o quanh tri t

Verification: kim tra bn c t chnh xc cha Validation: Cn thc hin vic xc nhn li sn phm cui cng so vi bn c t

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Quality (cht lng) v reliability (s tin cy):

Dng nh 2 khi nim ny l tng t nhau: 1 sn phm Reliability l 1 sn phm Quality

Nhng, Reliability ch l 1 kha cnh ca Quality Sn phm Quality:S thoi mi ca cc feature Dch v hu mi C th chy trn cc PC cu hnh thp Gi c ca sn phm

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Sn phm Quality v Reliability th phi thc hin verification v validation trong sut qu trnh pht trin sn phm41


Testing (Kim th) v quality assurance (m bo cht lng) (QA):

Mc ch ca testing l tm ra li, tm thy chng sm nht c th, v m bo rng chng c sa.

Trch nhim chnh ca ngi QA l to v bt phn mm phi tun theo cc chun ci tin quy trnh pht trin phn mm v ngn chn cc li xut hin bt c lc no

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2 khi nim ny c s chng cho Chng c mi quan h mt thit vi nhau42

2.2.3. M HNH CH VURS UAT planning User Acceptance Testing

SRS

System test planning

System Testing

VerificationHLD

ValidationIntegration Testing

Integration test planning

Delivery production deployment

LLD

Unit test planning

Unit testing

Maintenance and enhancement

Coding

2.3. QU TRNH NGHIN CU C T PHN MM 2.3.1. Kim tra c t mc cao 2.3.2. Kim tra c t mc thp

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2.3.1. KIM TRA BN C T MC CAO Bc u l xem xt spec mc cao => nghin cu chi tit tng vn => hiu r hn v phn mm v chc nng ca n => yu cu sa nhng im cha hp l => phc v cho qu trnh kim th

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2.3.1. KIM TRA BN C T MC CAOa) Nu bn l mt khch hng:

Tester xc nh i tng s dng sn phm l ai? Tester khng nht thit phi l chuyn gia trong lnh vc ca phn m m

Nhng nu tester c hiu bit v lnh vc => thun li cho qu trnh test

Bn buc phi hiu r c bn c t Lu ti kh nng bo mt ca phn mm (d khch hng c th tuyt i tin tng)46

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2.3.1. KIM TRA BN C T MC CAOb) Nghin cu v nhng Standard v Guideline

Thi k u ca Microsoft Windows v Apple Macintosh:

=> xy dng ln cc standard v guideline

Standard l chun c thng qua => bt buc phi tun theo Guideline l nhng hng dn, khng bt buc, nhng cng nn tun theo

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Khi xy dng mt phn mm, mt s Standard v Guideline s c la chn:

Cc thut ng v cc quy c ca cc t chc (Corporate Terminology and Conventions)

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Nhu cu ca ngnh cng nghip (Industry Requirements) Chun v chnh quyn (Government Standards) Giao din ha ngi dng (Graphical User Interface GUI) Tiu chun v s bo mt (Security Standards)48


La chn cc standard v guideline l cng vic ca cc ngi qun l hoc ngi vit bn c t

Tester phi hiu v cc standard v guideline ny, v xc minh li xem n c p dng trn phn mm nh th no (coi chng nh 1 phn ca bn c t)

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2.3.1. KIM TRA BN C T MC CAOc) Kim tra nhng phn mm tng t

Cch thc tt nht tm hiu ci m phn mm ca bn cn t n l nghin cu nhng phn mm tng t

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Mt s im cn xem xt trn cc phn mm cnh tranh: T l (scale): feature, code S phc tp (complexity) Kh nng kim th (testability): thi gian, chuyn mn, ti nguyn Cht lng / tnh tin cy (quality / reliability) Bo mt (security)50

2.3.1. KIM TRA BN C T MC CAOc) Kim tra nhng phn mm tng t

Nhng kinh nghim trn cc phn mm tng t => rt c ch cho qu trnh kim tra bn c t

nh gi bo mt ca cc phn mm tng t => so snh => a ra mc bo mt ph hp

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2.3.2. KIM TRA BN C T MC THPa) Danh mc nhng thuc tnh ca bn c t b) Nhng thut ng ca bn c t

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2.3.2. KIM TRA BN C T MC THPa) Danh mc nhng thuc tnh ca bn c t:

Hon thin (complete): Chnh xc (accurate): R rng, chnh xc, khng mp m v trong sng (Precise, Unambiguous, and Clear):

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Nht qun (consistent): Mi quan h (relevant): Kh thi (Feasible): M ngun m (code - free): Kh nng kim th (testable):53

2.3.2. KIM TRA BN C T MC THPb) Nhng thut ng ca bn c t

Lun lun, mi th, tt c, khng mt ai, khng bao gi (Always, every, all, none, never)

Tt nhin, bi vy, chc hn ri, hin nhin, r rng (Certainly, Therefore, Clearly, Obviously, Evidently)

Vn vn, v c tip tc pha trc, v c tip tc nh vy, v d (Etc., And So Forth, And So On, Such As)

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2.3.2. KIM TRA BN C T MC THPb) Nhng thut ng ca bn c t

Tt, nhanh, r, hiu qu, nh gn, n nh (Good, Fast, Cheap, Efficient, Small, Stable)

Danh hiu, quy trnh, loi b, b qua, loi tr (Handled, Processed, Rejected, Skipped, Eliminated)

Nu th nhng khng c trng hp cn li (IfThenbut missing Else)

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TNG KTy l cun sch gii thiu nhng ngi mun nhanh chng c

th kim th c mt bn c t. Nhng ni dung c m t phn ny s l cnh tay c lc tr gip tm ra nhng khuyt im trong nhng bn c t m bn phi kim th.Dng ca bn c t c th rt rng. Bn nn p dng nhng k

thut trong chng ny, kim tra mt s mc cao, phn tch nhng c php cu. Bn s tm thy li.Bn mun tm hiu nhiu k thut m rng: www.mfagan.com.05/26/11 56

BI 2. CU HI1.

Tn mt s nhim v s c thc thi trc khi lp trnh vin vit cc dng code u tin vi tng m hnh?

2.

Bn s gp phi nhng kh khn no nu bn mun xy dng mt bn c t chnh thc v cht li bn c t (formal, locked-down specification)?

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BI 2. CU HI3. 4.

u l feature tt nht ca m hnh big bang? Khi s dng m hnh code and fix, phn mm nh th no l giao ti tay khch hng?

5. 6.

Ti sao m hnh waterfall kh s dng? Ti sao cc tester thch m hnh spiral hn cc m hnh khc?

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BI 2. CU HI7. Bt u vi Windows Calculator. Hy g vo 5,000 5 = (du

phy l rt quan trng). V nhn kt qu. y c phi l li khng? Ti sao c v ti sao khng?8. C th tn ti mt sn phm c quality nhng li khng c

reliability? Hy ly v d?9. Hy gii thch mt tester nn lo ngi iu g vi dng c t

nh sau: Phn mm s cho php trn 100 triu kt ni ng thi, mc d bnh thng s khng c nhiu hn 1 triu kt05/26/11

ni.

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giao trinh software testing bai 2 2536

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