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7/25/2019 Selva.puli

1/19

Tuesday, Nov MIS 90-728 Lecture 1


2/19


3/19



4/19


Systems Development Lifecycle StepsTe S!L" #s $e%era&&y

'rese%ted as a% #terat#ve

se(ue%ce o) )#ve ste's*+ Systems &a%%#%$

+ Systems %a&ys#s

+ Systems !es#$%

+ Systems Im'&eme%tat#o%

+ Systems .'erat#o% a%d Su''ort,

eac cu&m#%at#%$ #% a

deverab&e, e#ter a /r#tte%

docume%t or a '#ece o)

so)t/are or bot

#$ure 11, Se&&y,

"asma% a%d5ose%b&att

S!L" a&&o/s or$a%#at#o%s to #%cor'orate %e/ re(u#reme%ts,

tec%o&o$y a%d uma% resources to IT deve&o'me%t


5/19

Tuesday, Nov MIS 90-728 Lecture

How Is the SDLC Used In This Class?"&ear&y, te S!L" re(u#res s#$%#)#ca%t t#me, uma% resources a%d

tec%#ca& resources to 'er)orm /e&&or te c&ass 'roect, your team must #m'&eme%t te S!L" ste's as

)o&&o/s*

+ Systems Planning'roect re(u#reme%ts summary, 'roect team descr#'t#o%,

'rem#%ary /or scedu&e, serv#ce area demo$ra'#c a%a&ys#s

+ Systems Analysis-5 d#a$ram, !ata &o/ !#a$rams, #$-&eve& )u%ct#o%a&

descr#'t#o%

+ Systems Design5!:M, !ata !#ct#o%ary, #de%t#)#cat#o%;descr#'t#o% o)

database obects,


6/19


,95T "art )or

-bbrev#ated Systems -%a&ys#s a%d !es#$% L#)e "yc&e

Systems Analysis Phase

Start

,rocess0!2!

Mode&

95

Mode&

5!:

Mode&

Test!ata

!ata

!#ct#o%ary

Start

Modu&e 1 =%#t 1

Test#%$

Modu&e N =%#t NTest#%$

:ase

Tab&es

=serI%ter)ace

I%te$rat#o% System

Test#%$

2#%#s

2#%#s

Development Phase

. . . . . .


7/19


Bsiness Analysis with Data !low Diag"ams


8/19


P"actical Significance of D!Ds

? Ma%y o&der #%)ormat#o% systems legacy systems*

+ re ma#%)rame-based #%access#b&e to most %o%-IT users>

+ =se %o%-re&at#o%a& #erarc#ca& databases, a%d

+ 5e(u#re seco%d-$e%erat#o% 'ro$ramm#%$ &a%$ua$es e$ ".:.L

to 'er)orm data #%'ut, (uer#es, re'ort#%$

Tus, ma%y IT 'ro)ess#o%a&s )ocus o% data flowsa%dphysical implementation, %ot data re&at#o%s#'s or 5!:M

des#$% 'r#%c#'&es

? Ma%y bus#%ess 'rocesses are so com'&e@ tat -5 des#$%

a&o%e /#&& %ot $#ve a%a&ysts #%s#$t #%to te#r bus#%esses

!!s a&&o/ te a%a&yst to determ#%e* $hatdoes te

or$a%#at#o% doAHowdoes te or$a%#at#o% do #tA


9/19


C"eating D!Ds

!e)#%e%ntities

? @ter%a& e%t#t#es re'rese%t'erso%s, 'rocesses or mac#%es

/#c 'roduce data to be used

by te system or rece#ve data

tat #s out'ut by te system

? @am'&es* Stude%t, "ustomer,"e%t

!e)#%eP"ocesses? rocesses are d#screte act#o%s

tat tra%s)orm #%'ut data toout'ut data? @am'&es* "reate Stude%t

5ecord, "a&cu&ate urcase

"ost, 5e$#ster "e%t

Stude%t

21

"reate

Stude%t5ecord


10/19


C"eating D!Ds &cont'd(!e)#%eData Sto"es

?!ata stores are tem'orary or'erma%e%t re'os#tor#es o) #%)ormat#o%

tat are #%'uts to or out'uts o)

'rocesses

? @am'&es* Stude%t Master, "e%t L#st

!e)#%eData !lows

? !ata )&o/s re'rese%t te tra%s)er o)

data over t#me )rom o%e B'&aceC

e%t#ty, 'rocess, data store to a%oter

? @am'&es* Ne/ Stude%t I%)ormat#o%

)rom Stude%t, to Stude%t Master

Ne/ Stude%t

I%)ormat#o%

Tem'&ates are 'osted #% l:\academic\90728\DFDSymbols.ppt

Stude%t

Master!3


11/19


C"eating D!Ds &cont'd(

!e)#%e te System

? system #s te co&&ect#o% o) a&&bus#%ess 'rocesses /#c 'er)orm

tass or 'roduce out'uts /e care

about It #s B/at a''e%sC

? Te system #s a s#%$&e 'rocess,

co%%ected to e@ter%a& e%t#t#es? 5e'rese%ted #% a B"o%te@t

!#a$ramC

!e)#%e S)systems

? subsystem $#ves a more deta#&edv#e/ #%d#v#dua& 'rocesses

co%ta#%ed #% te co%te@t d#a$ram

? I%c&udes data stores, more

e&eme%tary 'rocesses

#$ure 413,

Se&&y,"asma% a%d

5ose%b&att


12/19


D!Ds C"eated )y Top*Down Analysis? "reate a na""ative* descr#'t#o% o) system

? "reate a Conte+t Diag"amtat co%ta#%s

a s#%$&e 'rocess Bte systemC a%d a&&

e%t#t#es /#c sare data /#t te system

? %+plodete B'are%tC co%te@t d#a$ram to

'roduce a !#a$ram 0 Bc#&dC !!

? "reate !#a$ram 1, 2, D, n!!s tatre'rese%t Be@'&os#o%sC o) !#a$ram 0, 1,

D, n-1 !!s u%t#& a d#a$ram as o%&y

B'r#m#t#veC 'rocesses

? "reatep"ocess desc"iptionsto be

#m'&eme%ted by a''cat#o% 'ro$rams*(uer#es, macros, re'orts, 'ro$ramm#%$

&a%$ua$es

"o%te@t !#a$ram

!#a$ram 0 !!

!#a$ram 1 !!s

!#a$ram n!!s

Narrat#ve

-5 !#a$ram rocess !escr#'t#o%s


13/19


$he"e to Begin C"eating D!Ds

? Start /#t te data )&o/f"oma% e@ter%a& e%t#ty a%d /or)or/ards

? Start /#t te data )&o/ toa% e@ter%a& e%t#ty a%d /or

bac/ards

? @am#%e te data )&o/s #%to or out o) a data sto"e

? @am#%e data )&o/s, e%t#ty co%%ect#o%s a%d data stores

assoc#ated /#t a 'art#cu&arp"ocess

? Notef,,y- ill*definedareas o) te system )or )urterc&ar#)#cat#o%


14/19


$hat to Avoid in D!Ds

Ma#%$ te data )&o/ d#a$ram too

c&uttered e$ 9 'rocesses

4

er)orm5e'a#r

rocesses /#t %o out'uts or

%o #%'uts

1 2 3Ma%y 'rocesses /#t a s#%$&e

#%'ut a%d out'ut linea" flow

rocesses /ose #%'uts are

obv#ous&y #%ade(uate to y#e&d

out'uts

Eav#%$ data )&o/s term#%ate at

data stores

"o%%ect#%$ data stores d#rect&y

to eac oter

"ourses Stude%ts"&ass L#st

"o%%ect#%$ e%t#t#es to a%yt#%$

oter ta% 'rocessesayro&&

!e'artme%t

m'&oyees

rocess

rocess

:

rocess

"


15/19


D!D %+ample. Bs /a"age 0epai"s:uses come to a $ara$e )or re'a#rs

meca%#c a%d e&'er 'er)orm te re'a#r, record te reaso% )or te re'a#r a%d

record te tota& cost o) a&& 'arts used o% a So' 5e'a#r .rder

I%)ormat#o% o% &abor, 'arts a%d re'a#r outcome #s used )or b#&%$ by te

ccou%t#%$ !e'artme%t, 'arts mo%#tor#%$ by te #%ve%tory ma%a$eme%t

com'uter system a%d a 'er)orma%ce rev#e/ by te su'erv#sor

? 1ey p"ocessBte systemC* 'er)orm#%$ re'a#rs a%d stor#%$ #%)ormat#o%

re&ated to re'a#rs

? %+te"nal %ntities* :us, Meca%#c, Ee&'er, Su'erv#sor, I%ve%tory

Ma%a$eme%t System, ccou%t#%$ !e'artme%t, etc

? P"ocesses*

+ 5ecord :us I! a%d reaso% )or re'a#r+ !eterm#%e 'arts %eeded

+ er)orm re'a#r

+ "a&cu&ate 'arts e@te%ded a%d tota& cost

+ 5ecord &abor ours, cost


16/19


D!D %+ample. Bs /a"age 0epai"s

&cont'd(? Data sto"es*

+ erso%%e& )#&e

+ 5e'a#rs )#&e

+ :us master st

+ arts st

? Data flows*

+ 5e'a#r order

+ :us record

+ arts record

+ m'&oyee t#mecard+ I%vo#ces


17/19


:us

Meca%#c

Ee&'er0

:us5e'a#r

rocess

Su'erv#sor

ccou%t#%$

Bs /a"age Conte+t Diag"am

Meca%#ca&

'rob&em

to be re'a#red

Labor

Labor

#@ed

meca%#ca&

'rob&ems

I%ve%tory

Ma%a$eme%t

System

5e'a#r

summary

L#st o)

'arts used

Labor,

'arts cost

deta#&s


18/19


Bs /a"age Diag"am 2 D!D


19/19


Bs /a"age Diag"am 2 D!D &cont'd(

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