ch03-Phân tích hệ thống

8/14/2019 ch03-Phn tch h thng

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PhnPhn ttchch vv thithitt kk hh ththngng

Chng 3

PHN TCH H THNG

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I. Mt s khi nim c bn

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M hnh lung d liu

Cc m hnh h thng nh l tp cc chc nng tngtc

Cung cp cc chc nng x lS dng cc biu lung d liu (DFDs) biudin mt cch linh hot cc thc th ngoi, cc chcnng, lung d liu v cc kho d liu

Chra d liu nh th no c x l bi h thng

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K hiu lung d liu

Input: D liu vo

Output: D liu ra

Transform: Chc nng bin i d liu vo thnh d liu ra.

Terminators: Cc ngun v ch ca d liu

Data dictionary (data store): D liu trong vng lu tr tnh

Input Output

Transform

Terminator

Data dictionary


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Cc bc to DFD

To mc ng cnh DFD ca h thng chXem h thng nh l mt hp en

Nhn dng ranh gii h thng

Ranh gii gia h thng ch v mi trng bn ngoi

Nhn dng lung d liu vo v ra khi h thng (Chc nngmc nh)

Nhn dng cc ngun bn ngoi v ch ca d liu

Nhng ngi s dng v giao din bn ngoi

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Cc bc to DFD

Phn r chc nng mc nh vo cc chc nng conmc 1.

Cc chc nng tng ng cho bin i

Kt ni cc chc nng mc 1 vi cc u vo v u ra

Xc nh cc kho d liu (T in d liu)

Phn r cc chc nng con mc 1 vo cc chc nngcon mc 2

Phn r cc chc nng con mc 2 vo cc chc nng

con mc 3,

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V d: Biu lung d liu mc ngcnh

H thng c mong i t ng ho hot ng cath vin

Hai ngi dng bn ngoi (terminators)3 mc d liu vo

1 mc d liu ra

Mt chc nng mc nh (transform) -- Issue library item

mc thvin pht

hnh

Bnc

Th thvin

Yu cu

Kt qu

Nhnvin th

vin

a rangy

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V d: Biu lung d liu mc nh

Chc nng mc nh phn r ra thnh 4 chc nng con

u vo v u ra gia cc chc nng con

Hai kho d liu c nh dng

Bn c

Kim trabn c

CSDL Ttin

Kim trathng tin

th thvin

Tnh trngbn c

Yu cu

Issueitem

TnhtrngTtinTtin pht hnh

Cp nhtchi tit bn

c

UserID

ItemID

Cp nht chi titTtin chi tit

Nhn vinth vin

a ra ngy

CSDL bn c

Cp nht chi titChi tit bn c


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M hnh x l

M hnh x lKha cnh biu din ca x lCho php tri thc c dng li v x l c tip tc

Gim ri ro v tng tnh d on

y mnh phin bn chung v trau di

C/nng 1 C/nng 2vo u ra

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K hiu m hnh x l

Hot ng

Xl

Thc hin

Tc nhn ngoiVai tr

ng truyn

iu kin

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Cc thnh phn ca m hnh x l

Hot ngTrng thi lm vic vi i tng c th v vi iu kin tn

ti G k t

Chun b tp d liu kim tra kim tra module

M ho chc nng hoc module

Kim chng ti liu c

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Cc thnh phn ca m hnh x l

ProcessT chc tp cc hot ng chuyn t u vo thnh u ra

Phn tch yu cuThit k cu trc

Tch hp h thng


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II. Phn tch

Phn tch

Tp hp thng tin

M hnh x l

M hnh d liu

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Mt s nh ngha then cht

H thng cl h thng hin ti c th hoc khng th

c a vo my tnhH thng mi l mt h thng mi m da vo cc yucu c cp nht

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Mt s tng then cht

Mc ch ca giai on phn tch:Thc s hiu cc yu cu ca h thng mi

Pht trin h thng c sn hoc quyt nh mt h thng mikhng cn thit.

Ranh gii gia phn tch h thng v thit k h thngl khng r rt.

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QU TRNH PHN TCH


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Phn tch h thng IS l:Nhim v thng miNhim v IT

Cn s ngang bng chuyn mn gia ngi phn tchv ngi dng

Cc lnh vc phn tch

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Quy trnh SDLC

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Ba bc ca giai on phn tch

Hiu h thng c ( As-Is system)

Nhn bit c hi ci tin

Pht trin khi nim h thng mi?

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Ba bc ca giai on phn tch (cont)

Hiu h thng ch thng mi nhn c t h thng c

Khng th tp trung vo ci g ngi dng mun, cn phi hiu hmun ci g

Khng th tp trung vo phn phn tch kh cng, cn phi lngnghe kinh nghim ca ngi dng

Nhn bit c hi ci tinCn cc k nng thng mi v k thut

K nng thng mi

Tn dng trong qu trnh thng mi (chng ta lm g?)

K nng k thut

Tn dng chng ta thc hin nh th no?


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Pht trin khi nim h thng mi?Bt u a ra nh tp m ca nim ci tin c th xy raTinh ch vo trong khi nim h thng c th lm c

Kt thc qu trnh phn tch vi h thng c xut

xut cch biu din chp thun s ng trong biu mu cah thng tip theo

Ba bc ca giai on phn tch (cont)

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Mt s phc tho xut

Bng cc ni dung

Tm tt vic thc hinYu cu h thng

D kin cng vic

Chin lc phn tchTm tt cc nhim v phn tch

Gii thiu h thngTm tt cc khi nim h thng vi vic chng minh tnh ng n

Kh nng thay i khc nhau

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Phn tch tnh kh thi

M hnh hnh vi v cu trc

Ph lc, kt qu tng qut, phng vn, bo co,tim nng, kt qu thit k, ...Mt s iu cn thit cung cp

Mt s phc tho xut (cont)

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Chin lc phn tch c bn

BPAQu trnh t ng ho thng mi (Business process

automation)BPIQu trnh ci tin thng mi (Business ProcessImprovement)


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Qu trnh t ng ho thng mi(BPA)

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Qu trnh t ng ho thng mi

To ra hu ht khng thay i cho cc qu trnh thngmi

To ra chng hiu qu hn

Ci tin hiu qu bng t ng ho cc qu trnhthng mi

t tc ng trn nhng ngi s dngChng thc hin cc cng vic ging nhau, nh hiu qu hn

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1. (BPA) Hiu h thng c?

Mt s kt quh thng mi tip tc ng h h thng c

S tip tc thc hin cc cng vic ging nhau c bn

Xy dng cc m hnh hnh vi v cu trc chi tit dn chng ti liu h thng c

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2. (BPA) Xc nh cc c hi ci tin

Mt s ci tin n t mt s vn trong h thng hin ti

Hai k thut xc nh cc s ci tin:

Phn tch bi tonPhn tch ngun gc nguyn nhn


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3. Pht trin khi nim h thng mi

h thng mi kh tng t vi h thng cThay i khng thc t l qu trnh giao dch

Cc m hnh h thng mi khng khc so vi h thng c

Cc m hnh thng xuyn l c sao chp v cc thay inh c to ra

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Ci tin qu trnh thng mi (BPI)

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Ci tin qu trnh thng mi

Mc ch l ci tin qu trnh giao dch

Thay i ngi s dng lm g, khng phi hiu qu hthc hin chng nh th no

Thay i qu trnh giao dch phi c quyt nh utin

Quyt nh thay i qu trnh thng mi khng thc to ra bi ngi phn tch

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1. (BPI) Hiu h thng mi?

Vn cn nhng c gng n lc c ngha hiu hthng c

H thng mi cung cp phn ln h thng cH thng mi s c nhiu im ging nhau

Nhng mt s qu trnh l khc


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2. (BPI) Xc nh cc c hi ci tin

Tiu im xem xt s c gng:Nhn vo s ci tin ca qu trnh thng mi

Ngi s dng v ngi qun l cc hot ng tm kim tng thng mi mi v cc c hi mi

4 k thut xc nh cc c hi thc hin1. Trong thi gian phn tch

2. Da vo chi ph hot ng

3. im chun khng chnh thc

4. im chun chnh thc

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Thi gian phn tch

Thi gian tnh ton cho mi bc x lThi gian tnh ton cho ton b qu trnh

So snh: Nu (thi gian cho mi bc ring r) nh hn(thi gian ton b qu trnh) th s c mt bi ton

S cn thit pht trinQu trnh tnh hp hocTnh ton song song

Khi c nhiu ngi khc nhau lm vic trn mt phnnh ca ton b qu trnhQu trnh tch hp

Qu trnh thay i c bn cho t ngi lm vic trn u voThc hin song song

Thay i qu trnh m trong nhiu ngi c th thc hin cngcng vic ti cng mt thi im

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Phm vi hot ng da vo chi ph

Tnh ton gi chi ph cho mi bc x l

Xem xt c chi ph trc tip v chi ph gin tip

Xc nh cc bc tn km nht v tp trung n lctrn chng

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Chun mc

Nghin cu cc t chc khc thc hin x l thngmi ging nhau nh th no

Chun mc khng chnh thcKim tra vi cc khch hng

V tr nh cc khch hng

Chun mc chnh thc

Thit lp chnh thc quan h

vi cc t chc khc


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3. (BPI) Pht trin khi nim h thng mi

Mt s lng nh tp thng tin l cn thit

h thng mi tng t nh h thng cNhng mt s chc nng c thc hin li trn vn

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Pht trin d n phn tch

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Pht trin d n phn tch

K hoch phn tch:t k hoch cho cc hot ngtrong giai on phn tch

La chn chin lc phn tch u tinXc nh bi ngi u d n

N l mt quyt nh thng mi

Tim lc gi tr thng mi

Chi ph d n

M rng phn tch

Mo him

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Chin lc phn tch

Tim lc gi tr thng miBPA Li nhun l chin lc v khng quan trngBPI Tim nng li nhun l va phiBPR Tim nng li nhun ln nht

Chi ph li nhunBPA Mc tiu kh khn, khng tBPI Ph thuc vo mc tiu, c th khng t lmBPR Phn ln lun lun t

M rng phn tchBPA Mc tiu rt nh trong h thng hin tiBPI t hn, nhng thng thng trong phm vi hpBPR Trin vng rng, mc tiu trn nhiu qu trnh thng

mi


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Mo him ca vic sai st da vo:Khng c kh nng hon thnh h thng

H thng hon ton khng c kh nng thc hin li nhunthng mi

BPA Mo him thp

BPI Thp va phi

BPR Cao (h thng mi hon ton)

Chin lc phn tch (cont)

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Cc tnh cht ca chin lc phn tch

Business Business BusinessProcess Process ProcessAutomation Improvement Reeingineering

Potential Business Low-Moderate Moderate HighValue

Project Cost Low Low-Moderate High

Breadth ofAnalysis Narrow Narrow-Moderate Very Broad

Risk Low Low-Moderate Very High

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Trnh cc li phn tch c in

Gim thi gian phn tchGii php?

S dng RAD v hp thi gianYu cu

Nhng c trng khng cn thit c a vo

Xc nh nhng c trng ca ngi dng

Gii php?

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Tm tt

Qu trnh phn tch tp trung vo vic to ra gi tr chot chc

Mt s chin lc phn tch chnh BPA, BPICc chin lc ny thay i trong tim nng gi trthng mi, nhng cng trong tim nng chi ph vmo him

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