IT4460-Slide-Chapter 2.1

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PHN TCH YU CU PHN MM

Nm hc 2014-2015

Gio vin: PGS.TS. Hunh Quyt Thng

BM Cng ngh phn mm

Vin CNTT-TT, HBK HN

www.soict.hust.edu.vn/~thanghq

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Chng 2. Pht hin, tng hp v phn tch YCPM

1. Ngun gc yu cu phn mm

2. Quy trnh pht hin yu cu phn mm v phn nhm NSD

3. Cc k thut pht hin yu cu phn mm

4. Tng hp v phn tch cc yu cu phn mm

5. Thng lng v tha thun cc yu cu phn mm

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1. Ngun gc yu cu phn mm

Ngun gc yu cu phn mm t ngi s dng Ngi s dng (Khch hng): theo m hnh phn

lp ca yu cu phn mm Khch hng c chia lm hai loi: Khch hng cung cp cc business requirement:

cung cp cc thng tin v cng ty, v cc c im mc cao, v m hnh v phm vi ca h thng

Khch hng cung cp cc user requirement: cung cp cc cng tin v tng nhim v c th m h s lm vic vi phn mm

Cn phi phi hp, kt hp cht ch vi hai phn loi khch hng trn

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1. Ngun gc yu cu phn mm

Cc kh khn c th xy ra trong xy dng yu cu phn mm

(1) S tham gia qu mc ca NSD: Thng thng ngi s dng khng hiu r v qu

trnh xy dng cc yu cu phn mm v cc c im ca phn mm.

H s a nhng i hi qu cao hoc chng lin quan n qu trnh pht trin phn mm nh vit code, ...

H a ra nhng yu cu v ngh rt kh chp nhn v gy kh khn cho cc PTV

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1. Ngun gc yu cu phn mm

Cc kh khn c th xy ra trong xy dng yu cu phn mm (tip)

(2) C qu nhiu yu cu trong yu cu phn mm: Thng thng cc yu cu phn mm c pht hin

trong qu trnh kho st v rt c th cc yu cu v phn mm s ln hn kh nng ca i ng ph trin phn mm v: nhn lc, thi gian, ti chnh.

Cn hn ch khng cc yu cu phn mm ph sinh i qu phm vi v gii hn ca phn mm.

Cn qun l cc thay i v yu cu phn mm mt cch hp l v xem xt nh hng ca ni ti kin trc h thng, ... trong qu trnh pht trin

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1. Ngun gc yu cu phn mm

(3) Cc yu cu phn mm m h nhp nhng: y l mt vn rt hay xy ra trog qu trnh pht trin

cc yu cu phn mm Cc yu cu phn mm cn phi r rng, khng c

php hiu theo nhiu cch Phng php sa cc yu cu m h nhp nhng l

lm li, c t li cc yu cu ny. Theo nh gi ca cc nh phn tch: lm li yu cu

phn mm thng chim khang 40% qu trnh xy dng n v 70, 80% cc c tnh xy dng li c th dn n cc li

Lu ti tng yu cu phn mm v khng st nhng yu cu m h, khng r rng

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1. Ngun gc yu cu phn mm

(4) Cc c tnh tha: Thng thng ngi pht trin theo cc thi

quen ngh nghip thm vo cc yu cu phn mm cc chc nng khng cn thit cho phn mm

Tng t nh th ngi s dng c th a ra mt s yu cu ph cho phn mm. Cc yu cu ny c th i hi cc tn km v mt xy dng m trn thc t hon ton khng cn thit.

Cn nh gi cc c tnh v tnh cn thit ca n i vi cc phn mm. Nhng c tnh ph c th xem xt k hn xem kh nng p ng n v mt k thut c ng gi hay khng

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1. Ngun gc yu cu phn mm

(5) c t qu t: NSD l chuyn vin trong mt lnh vc no c

thi quen ngh rng tt c cc PTV u l cc chuyn vin trong lnh vc .

NSD a ra nhng yu cu qu ngn gn m khng miu t k lng hn chng l g

Cn hi r NSD v tranh th cc kin thc ca h (6) Khng lu ti nhng ngi s s dng phn

mm: Thng thng phn mm lm ra cho mt tp hp

cc i tng no s dng Cn quan tm ti c im ca cc i tng ny

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1. Ngun gc yu cu phn mm

(7) K hoch sai Cc PTV nh gi sai v mc phc tp ca

vn v dn ti lp k hoch sai v thi gian hon thnh

Cn lu nh gi tht chc chn cc c tnh ca phn mm khi lp k hoch xy dng phn mm

Nn tr li cho khch hng cc cu tr li dng gn chnh xc: trong trng hp xu nht ...., nu ....... th.

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Cc quyn (bill of right) ca khch hng

(1) Yu cu cc PTV s dng cc ngn t thng dng (khng c nhiu cc thut ng tin hc)

(2) Yu cu cc PTV hc cc vn v cng vic ca khch hng

(3) Yu cu PTV vit cc c t yu cu phn mm

(4) C quyn i gii thch v tt c cc vn trong c t yu cu phn mm

(5) Yu cu s i x lch s t cc PTV (6) Lng nghe cc tng mi v cc cch thc

hin khc ca cc yu cu phn mm, khng nn ngay lp tc ph nh khi thy n khc vi cch thng dng m mnh ang s dng

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Cc quyn (bill of right) ca khch hng

(7) Gii thch cc c im ca cng vic v phn mm n c lm tt hn, d s dng hn

(8) Cn suy ngh v phn mm iu chnh cc yu cu sao cho tng kh nngti s dng cc chc nng ca n

(9) Cn nh gi ng gi thnh ca cc yu cu hay cc s thay i trong phn mm

(10) Cn i hi h thng p ng y cc yu cu v chc nng v cht lng nh mong mun

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Cc trch nhim ca khch hng

(1) Khch hng c trch nhim o to cc PTV v cng vic ca h (khch hng)

(2) Khch hng c trch nhim dnh thi gian chun b chu o v r rng cc yu cu

(3) Khch hng cn c cc yu cu tht c th (specific) v tht chnh xc (precise)

(4) Khch hng cn c trch nhim quyt nh kp thi chnh xc v nhng im tranh lun vi cc LTV

(5) C trch nhim tn trng nhng nh gi ca cac PTV v gi thanh fv tinh skh thi ca phn mm

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Cc trch nhim ca khch hng

(7) Khch hng c trch nhim gn cc quyn (trng s) u tin cho cc yu cu t ra.

(8) Khch hng c trch nhim duyt li cc c t yu cu v nguyn mu (prototype) yu cu

(9) Khch hng c trch nhim thc hin kp thi, khng c php chm tr nhng thay i yu cu nu iu l cn thit.

(10) Khch hng c trch nhim tn trng cc quy trnh thc hin trong cng ngh hc xc nh yu cu phn mm v cng ngh phn mm

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Chng 2. Pht hin, tng hp v phn tch YCPM

1. Ngun gc yu cu phn mm

2. Quy trnh pht hin yu cu phn mm v phn nhm NSD

3. Cc k thut pht hin yu cu phn mm

4. Tng hp v phn tch cc yu cu phn mm

5. Thng lng v tha thun cc yu cu phn mm

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Chng 2. Pht hin, tng hp v phn tch YCPM

1. Ngun gc yu cu phn mm

2. Quy trnh pht hin yu cu phn mm v phn nhm NSD

3. Cc k thut pht hin yu cu phn mm

4. Tng hp v phn tch cc yu cu phn mm

5. Thng lng v tha thun cc yu cu phn mm

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2. Quy trnh v k thut pht hin cc yu cu phn mm

(Software Elicitation)

1. Xc nh qu trnh pht trin cc yu cu phn mm

2. Xy dng kh nng (vision) v phm vi (scope) ca phn mm

3. Xc nh cc nhm ngi s dng v c tnh ca h v i din tiu biu cho mi nhm

4. Phn tch v xc nh cc yu cu phn mm da trn cc i din ca cc nhm NSD

5. Xy dng cc c tnh xc nh cht lng yu cu v cc yu cu khc (non-functional requirement)

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2.1. Xc nh qu trnh pht trin cc yu cu phn mm

Xc nh cc bc v ti liu m t quy trnh chng ta s thc hin qu trnh pht trin cc yu cu phn mm

M t phng php xc nh cc NSD trong phm vi bi ton ca phn mm v cc k thut s s dng pht hin cc yu cu phn mm

M t ccc t hoc cc m hnh phn tch ca phn mm

Cc thng tin cho mi yu cu, trng s ca yu cu Cc bc tin hnh pht hin cc yu cu, phn tch

yu cu

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

Kh nng v phm vi ca phn mm tp hp cc yu cu phn mm mc cao (business requirement)

M t kh nng, mc tiu ca phn mm, cc phm vi ng dng ca phn mm, cc hn ch ca phn mm, mt s c im ca ng dng: ai s dng, trong m trng no

Thng thng tt c cc thg tin ny c m t ngn gon trong 3-8 trang theo cu trc nh sau:

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

Cu trc ca ti liu: 1. Yu cu phn mm (mc cao business) 1.1. C s (background) 1.2. C hi 1.3. i tng 1.4. Yu cu khch hng hay yu cu th trng 1.5. Cc gi tr cung cp cho khch hng 1.6. Cc ri ro 2. Kh nng ca phn mm (vision of solution) 2.1. Cc kh nng 2.2. Cc c im 2.3. Cc ph thuc v chp nhn

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

Cu trc ca ti liu: 3. Phm vi v gii hn (scope and limitation) 3.1. Phm vi ca phin bn u 3.2. Phm vi ca cc phin bn tip theo 3.3. Hn ch v ngoi l 4. Ng cnh cng vic (business context) 4.1. Tiu s khch hng 4.2. Cc trong s d n 5. Cc yu t thnh cng ca d n

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

1. Yu cu phn mm (mc cao business requirement) M t cc c im chnh m phn mm mi s cung

cp cho khch hng. Thng thng phn ny rt khc nhau cho nhng phn mm khc nhau

1.1 C s (background) M t l do hp l cn pht trin phn mm mi: tai

sao, c s no. C th gii thch tng th lch s hoc tnh hung quyt nh cn phi xy dng phn mm

1.2. C hi (business opportunity) M t c hi trn th trng ang tn ti vn m

phn mm s gii quyt. C th m t ngn gn mt s phn mm tng t v cc c tnh ca chng v gii thch ti sao can lm phn mm ny

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

1.3. i tng/mc tiu M t mc tiu m phn mm gii quyt 1.4. Yu cu khch hng hay yu cu th trng M t cc i tng khch hng m phn mm s phc

v. 1.5. Cc gi tr cung cp cho khch hng M t chi tit cc kh nng ca phn mm s cung cp

cho khch hng:

- Kh nng gii quyt cng vic - Kh nng tit kim - Kh nng t ngha cc cng vic trc y ....

1.6. Cc ri ro M t cc ri ro ca cng vic khi pht trin phn mm.

nh gi cc ri ro v cc phng php trnh

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

2. Kh nng ca phn mm (vision of solution) M t cckh nng ca phn mm. ay s khng m t

cc chc nng phn mm 2.1. Cc kh nng M t chnh xc ngn gn cc mc ch di hn ca phn

mm 2.2. Cc c im Danh sch cc c im chnh ca phn mm. Cc c

im ny s khch nhng phn mm tng t nh th no

2.3. Cc ph thuc v chp nhn Ghi nhn li cc ph thuc v cc chp nhn thc

hin trong phn mm

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

3. Phm vi v gii hn (scope and limitation) M t cc gii hn v kh nng ca phn mm. Phn

mm ch gii quyt bi ton mc nh vy 3.1. Phm vi ca phin bn u Cc phm vi ca phin bn u (1.0) 3.2. Phm vi ca cc phin bn tip theo Cc phm vi ca cc phin bn tip theo 3.3. Hn ch v ngoi l M t cc hn ch v ngoi l ca phn mm 4. Ng cnh cng vic (business context) 4.1. Tiu s khch hng 4.2. Cc trong s d n 5. Cc yu t thnh cng ca d n

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2.2. Xy dng kh nng (vision) v phm vi (scope) ca

phn mm

4. Ng cnh cng vic (business context) 4.1. Tiu s khch hng Cc c im ca khch hng: Phn loi khch hng 4.2. Cc trong s d n Chia lm 03 loi: Cc mc tiu chnh ca phn mm (objectives) Cc rng buc v hn ch (constraint) Mc t do ca phn mm (kh nng cn i gia mc

tiu v cc rng buc) 5. Cc yu t thnh cng ca d n Cc yu t lm d n kh thi Cc yu t chng t kh ng cnh tranh ca phn mm

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2.3. Xc nh cc nhm ngi s dng v c tnh ca h

v i din tiu biu cho mi nhm

(1) Phn lp ngi s dng phn mm (user classes) Phn loi theo c im Phn loi theo v tr a l Phn loi theo vai tr cng vic Phn loi theo chc nng Lit k cc phn loi (cc lp) v m t chi tit cc c

im ca NSD tng lp (2) Tm cc NSD tiu biu (presentative user) (3) Khi nim Product Champion: Nhng i din tiu biu

ca tng nhm ngi s dng. Trn thc t cc yu cu phn mm s c pht hin t nhng khch hng ny

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2.3. Xc nh cc nhm ngi s dng v c tnh ca h v

i din tiu biu cho mi nhm

Manager

Analyst 1

Analyst 2

Analyst n

Product

Champion 1

Product

Champion 2

Requirement

Product

Champion n

Requirement

Requirement

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2.4 Phn tch v xc nh cc yu cu phn mm da trn

cc i din ca cc nhm NSD

Nguyn tc ca pht hin yu cu phn mm: (1) nh ngha phm vi v gii hn phn mm (2) Xc nh cc phn nhm ngi s dng (3) Xc nh cc i din ca tng nhm (4) Xc nh Product Champion ca tng nhm (5) La chn k thut pht hin yu cu phn mm (6) p dng k thut cho tng i din - Product Champion (7) Xy dng cc tiu thc cht lng (8) Chi tit ha (chuyn ha) cc trng hp s dng thnh

chc nng phn mm (9) Xem xt cc trng hp s dng v chc nng (10) Pht trin m hnh phn tch, gii thch v lm r vi cc

khch hng

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2.4 Phn tch v xc nh cc yu cu phn mm da trn

cc i din ca cc nhm NSD

Nguyn tc ca pht hin yu cu phn mm: (11) Pht trin v nh gi giao din cho tng yu cu (12) Pht trin cc trng hp kim th cho cc yu cu (13) S dng cc trng hp kim th kim tra (14) Lp li cc bc 6-13 trc khi thit k

1 2 3 4 6 5 7

8 9 10 11 13 12

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2.4 Phn tch v xc nh cc yu cu phn mm da trn

cc i din ca cc nhm NSD

Pht hin cc yu cu phn mm l mt cng vic phc tp

y chnh l cu ni gii quyt bi ton y chnh l cu ni gia PTV v NSD i hi rt nhiu n lc v cc phm cht ca

PTV

Mt trong nhng k thut tiu biu xc nh v pht hin cc yu cu s dng l Trng hp s dng- use-case

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2.4 Phn tch v xc nh cc yu cu phn mm da trn

cc i din ca cc nhm NSD

Use-case: Th hin tp hp cc tng tc gia cc tc nhn (actor) v h thng

Actor (tc nhn):

Trng hp s dng:

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2.4 Phn tch v xc nh cc yu cu phn mm da trn

cc i din ca cc nhm NSD

use-case

workshops

Use-Case

Description

Draft

Functional

Requirement

Draft Test

Case

Draft

Analysis

Models

Verified

Functional

Requirement

Veryfied

Analysis

Model

Common

Understanding

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2.4 Phn tch v xc nh cc yu cu phn mm da trn

cc i din ca cc nhm NSD

Cc li thng hoc l nhng im nn trnh trong pht hin yu cu:

(1) C qu nhiu use-case (2) C cc use-case trng lp (3) Trong m hnh use-case xy dng khng nn

a vo giao din vi NSD (4) nh ngha d liu trong cc use-case (5) C gng gn mi yu cu vi mt use-case