LOGIC MỜ TRONG PHÂN TÍCH DỰ ÁN PHẦN MỀM

8/12/2019 LOGIC M TRONG PHN TCH D N PHN MM

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Khoa Khoa Hc My Tnh Mn hc Ton Hc Cho Khoa Hc My Tnh

p Dng Logic M Trong Phn Tch D n Phn Mm Trang 1

TRNG I HC CNG NGHTHNG TIN

KHOA KHOA HC MY TNH

MN HC: TON HC CHO KHOA HC MY TNH

TI: P DNG LOGIC MTRONG PHN TCH DN PHN MM

CBHD: PGS. TS. VN NHN

HC VIN: TRN MNH TNG CH1301070

TP HCM 12-2013


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Mc LcDANH MC K HIU V TVIT TT ............................................................................................... 3

I. T VN ...................................................................................................................................... 4

II. KHI NIM QUN L DN PHN MM .................................................................................. 5

1. Qun l dn .................................................................................................................................... 5

1.1 Khi nim ........................................................................................................................................ 5

1.2 Cc nhn tnh hng ti dn .................................................................................................... 5

1.4 Cc giai on ca qun l dn ..................................................................................................... 7

1.5 Cc lnh vc trong qun l dn .................................................................................................... 7

1.6 Vai tr ca ngi qun l dn...................................................................................................... 9

2. Qun l dn phn mm ................................................................................................................ 11

2.1Khi nim: ..................................................................................................................................... 11

2.2 Quy trnh qun l dn phn mm............................................................................................... 11

2.3 Cc hot ng chnh trong qun l dn phn mm.................................................................... 14

III. KHI NIM VLOGIC M ........................................................................................................ 18

1. Tng quan vLogic m .................................................................................................................. 18

2. Khi nim tp m ............................................................................................................................ 18

3. Bin ngn ng ................................................................................................................................. 22

4. Kin trc hm ............................................................................................................................... 29

5. Bsuy din m ............................................................................................................................... 31

IV. NGHIN CU P DNG LOGIC MTRONG PHN TCH DN PHN MM............... 34

V. KT LUN ......................................................................................................................................... 37


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DANH MC K HIU V T VIT TTK hiu, chvit tt ngha

PM Project Management. Ngi qun l dn

Estimate Hot ng c lng, thay dng trong qun l dn phn mm.

Effort Chi ph cn dng cho lm dn. n vc thlngy hoc thng, nm ty vo quy nh ca micng ty.

LOC Line of Code. Sdng code, dng tnh mc ln nhca dn

Productivity Nng sut lm vic. Trong dn phn mm th cthl strang design trn mt ngy, sLOC codec trong mt thng.

CSS Customer satisfaction survey. Chskho st hi lng ca khch hng.

Risk Nhng ri ro c thxy ra trong dn

Leakage Nhng li m sau khi gi sn phm cho khch

hng, khch hng bt c li.

Timeliness Tham schsng thi gian cam kt vi khchhng.

WO Work Order. Tn ti liu trong Fsoft, c ghi nidung ca dn v cc bn lin quan.

PP Project Planning. . Tn ti liu trong Fsoft, c ghini dung ca dn v cc chin lc lm dn

ca ngi qun l dn.

Bug Tchli trong lm dn phn mm.


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I. T VN Trong thi i ngy nay, khi sc p thay i cng nghngy cng ln v cnh

tranh khc lit buc cho cc doanh nghip phn ng kp thi vi nhng thay i

ca mi trng, hot ng theo hnh thc cc dn tr thnh mt phng thc

vn hnh hu hiu i vi cc tchc. Tchc theo hnh thc dn cung cp cc

cng chu hiu nhm tng cng khnng hoch nh, thc thi v kim sot

hot ng, nhn lc v ngun lc ca tchc. Qun trdn trln cn thit bi

x hi hin i i hi nhng phng php qun trmi trong sdng nhm

thay v c nhn gii quyt vn . Ngoi ra, khi mc phc tp ca cc dch

vv sn phm v cng nh cc quy trnh sn xut ra chng ngy cng ra tng,

dn chnh l mt cng chiu qukim tra cc sn phm cng nh quy trnhsn xut. Mt trong nhng yu tquan trng quyt nh thnh cng ca dn l

planning, planning bao gm vic c lng resources, c lng chi ph, nh gi

ri ro, chn ngi qun l, a ra cc Mertrics m bo cht lng. Tt ccc yu

tnh hng ti dn u c a ra phn tch nh gi klng. Nhng thc

t khng phi cc d liu, con s u vo ca d n no cng l r rng minh

bch. C rt nhiu nhng yu t m bn thn ngi lm qun l cha th chc

chn, cha thm bo n thuc ranh gii no, ngng no lm khoch choph hp. Nhng yu t c th l nhng issue, risk, hay mt ci g khc xut

hin trong qu trnh lm dn.

Logic mc ng dng trong rt nhiu lnh vc khoa hc khc nhau nh iu

khin hc, khoa hc nhn dng, tng ha, v c bit l trong cc ng dng

ca cng nghthng tin. Bi vit ny scp n nhng ni dung ca logic m,

qun l dn phn mm. T a ra tng xy dng ng dng logic m

vo phn tch d n phn mm. Trong bi vit c nghin cu, s dng mt s

thut ng, quy trnh lm dn thc tca Fsoft-FPT.


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II.KHI NIM QUN L D N PHN MM1. Qun l dn

1.1 Khi nim

Qun l dn l ngnh khoa hc nghin cu vvic lp khoch, tchc v qun

l, gim st qu trnh pht trin ca dn nhm m bo cho dn hon thnh

ng thi gian, trong phm vi ngn sch c duyt, m bo cht lng, t

c mc tiu cthca dn v cc mc ch ra.

Mc tiu c bn ca vic qun l dn thhin chcc cng vic phi c

hon thnh theo yu cu v bo m cht lng, trong phm vi chi ph c duyt,

ng thi gian v gicho phm vi dn khng thay i.

1.2 Cc nhn tnh hng ti dn

Cc bn tham gia l tt cnhng ai c lin quan hoc bnh hng bi cc hot

ng ca dn, cth:

- C li ch nghip vtrong kt qudn

- Lin quan trc tip ti dn

- ng gp cc ngun lc cho dn

Cc bn lin quan dn c nhng li ch, nhu cu v u tin khc nhau. Hc th

c nhng quan im khc nhau vvic d n cgng hon thnh nhng g. Do

, vic xc nh c cc bn lin quan trong dn cng sm cng tt, c bit

trong giai on xy dng tng. Xem qua cc bn lin quan cn cha ldin s

l mt ri ro rt ln n vic tchc thc hin dn. Thng thng, trong mt d

n, cc bn tham gia bao gm:

- Nh ti tr:

+ Chu trch nhim cui cng i vi sthnh cng ca dn. Nh ti trc trch

nhim k kt hon tt cc ti liu lp khoch v cc yu cu thay i.


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+ ng thi cho php nhm qun l dn sdng cc ngun lc, bo vv c

vn cho nhm qun l dn.

+ Trong qu trnh thc hin dn, nh ti trc thm cc trch nhim xem xt li

cc

tin trnh v cht lng, ct bng khai trng, khnh thnh, k v cng btn ch

dn.

- Nh qun l dn (gim c dn):

+ Lm vic vi cc i tng lin quan nh ngha dn

+ Lp khoch, sp xp lch trnh v dtho ngn sch cc hot ng ca dnvi i ng ban u; chi huy nhm dn thc thi khoch + Gim st hiu qu

hot ng v thc hin cc hot ng hiu chnh.

+ Thng xuyn thng bo cho nh ti trv cc i tng lin quan dn: a

ra yu cu v trnh by nhng thay i v phm vi + ng vai tr l ngi trung

gian gia nhm dn v cc i tng lin quan + - Nh qun l chc nng: Cc

nh qun l ny chu nh hng bi cc hot ng hay kt quca dn.

+ Kim sot v ng gp ngun lc cho dn (con ngi, trang thit b.)

+ C thc nhng yu cu tri ngc vi kt qudn

+ Trong mt strng hp l cp trn ca nh qun l d n

+ - Khch hng: Trong trng hp nh ti trkhng phi l n vtrin khai sn

phm ca dn th nh ti trchnh l khch hng. i tng ny c nhim v

nh sau:

+ Nhn u ra ca dn

+ Thanh ton cho u ra dn


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+ Xc nh nhu cu cho u ra dn

+ C thl nhiu cng ty hay c nhn vi nhng c im v yu cu tri ngc

nhau

- Nh cung cp: mt dn thng bao gm nhiu hng mc khc nhau, trong

c nhng hng mc khi xem xt yu tkhthi, nh ti trquyt nh mua. Nh

cung cp c trch nhim cung cp cc thit b, sn phm hay dch v cn thit

phc vcho hot ng ca dn thng qua hnh thc hp ng, m bo dn

t c mc tiu ra.

1.4 Cc giai on ca qun l dn

+ Khi ng dn: giai on c thng tin mdn, dtr con ngi v hthngc svt cht.

+ Lp khoch dn: y l giai on xy dng mc tiu, xc nh nhng cng

vic cn c hon thnh, ngun lc cn thit thc hin dn v l qu trnh

pht trin mt khoch hnh ng theo trnh t logic m c th biu din di

dng s hthng.

+ Thc hin dn: Tin hnh lm dn theo khoch ra.

+ Theo di v kim sot dn: l qu trnh theo di, kim tra tin trnh d n,

phn tch tnh hnh hon thnh, gii quyt nhng vn lin quan v thc hin bo

co tnh hnh dn.

+ Kt thc dn

1.5 Cc lnh vc trong qun l dnTheo i tng qun l, qun l dn bao gm 9 lnh vc chnh cn c xem

xt, nghin cu l:

- Lp khoch tng th: lp khoch cho dn l qu trnh tchc dn

theo mt trnh tchng trnh thc hin nhng cng vic nhm m bo


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cc lnh vc qun l khc nhau ca dn c kt hp mt cch chnh xc

v y .

- Qun l phm vi: L vic xc nh phm vi, gim st vic thc hin mc

ch, mc tiu ca dn, xc nh cng vic no thuc v dn v cn phithc hin, cng vic no nm ngoi phm vi ca dn.

- Qun l thi gian: L vic lp khoch, phn phi v gim st tin thi

gian nhm m bo thi hn hon thnh dn. N chr mi cng vic phi

ko di bao lu, khi no th bt u, khi no th kt thc v ton bdn ko

di bao lu, phi hon thnh khi no.

- Qun l chi ph: L qu trnh dton kinh ph, gim st thc hin chi phtheo tin cho tng cng vic v ton bdn. Cthl tchc, phn tch

sliu, bo co nhng thng tin vchi ph.

- Qun l cht lng: L qu trnh trin khai gim st nhng tiu chun cht

lng cho vic thc hin dn, m bo cht lng kt quca dn phi p

ng mong mun ca nh ti tr(chu t).

- Qun l nhn lc: L qu trnh hng dn, phi hp nhng nlc ca mi

thnh vin tham gia d n vo vic hon thnh mc tiu ca d n. N cho

thy vic sdng lc lng lao ng ca dn hiu qun u,

- Qun l thng tin (truyn thng): L qu trnh bo m cc dng thng tin

thng sut, nhanh chng v chnh xc gia cc thnh vin dn v vi cc cp

qun l, gia cc tnhm qun l dn. Thng qua qun l thng tin c th

trli cc cu hi: ai cn thong tin vdn, mc chi tit, cc nh qun ldn cn bo co cho hbng cch no,

- Qun l ri ro: L vic nhn din cc nhn tri ro trong dn, sdng

cc phng phpnh tnh, nh lng xc inh tnh cht, mc ri ro v

c khoch i ph cng nh qun l tng loi ri ro.


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- Qun l hp ng v cc hot ng mua sm: L qu trnh la chn nh

cung cp hng ho v dch v; thng lng vi h, qun l cc hp ng v

iu hnh vic mua bn nguyn vt liu, trang thit b, dch vnhm gii quyt

ccvn : bng cch no cung cp cc hng ho, vt liu cn thit cho dn,

tin cung cp, cht lng cung cp n u.

1.6 Vai tr ca ngi qun l dn

Phn ln kin thc cn thit qun l d n l kin thc ring ca ngnh

qun l dn. Ngoi ra, Ngi qun trdn cn phi c kin thc v kinh

nghim trong:

- Qun l tng qut

- Lnh vc ng dng ca dn

Cc knng cn thit ca nh qun l dn:

- Knng lnh o: Lnh o l knng c bn nh qun l dn ch

o, nh hng, khuyn khch v phi hp cc thnh vin trong nhm cng

thc hin dn. y l knng quan trng nht. N i hi cc nh qun l

dn c nhng phm cht cn thit, c quyn lc nht nh thc hin thnh

cng mc tiu dn.

- Knng lp khoch v kim sot dn: Nh qun l dn phi l ngi

chu trch nhim vkhoch tng thtrc nh ti trv khch hng. V vy,

nh qun l dn phi c knng lp lch trnh dn v xc nh cc tiu ch

nh gi cng vic hon thnh. ng thi, nh qun l dn phi bit thit

lp cc quy trnh h thng nh gi v kim sot mc thnh cng cabng khoch.

- Knng giao tip v thng tin trong qun l dn: Nh qun l dn c

trch nhim phi hp, thng nht cc hot ng gia cc bphn chc nng v

nhng c quan lin quan thc hin cc cng vic ca dn nn bt buc


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phi thnh tho knng giao tip. Nh qun l dn phi c kin thc, hiu

bit cc cng vic ca cc phng chc nng, c kin thc rng vmt slnh

vc kthut. Nh qun l dn cng cn gii knng thng tin, truyn thng,

knng chia sthng tin gia cc thnh vin dn v nhng ngi lin quan

trong qu trnh trin khai dn.

- Knng thng lng v gii quyt kh khn vng mc: Nh qun l d

n trong qu trnh thc hin trng trch ca mnh c quan h vi rt nhiu

nhm. ng thi, cng vi spht trin t chc ca dn, trch nhim ca

nh qun l d n ngy cng tng nhng quyn lc ca hc cp khng

tng xng. Do thiu quyn lc, bt buc cc nh qun l phi c k nng

thng lng gii vi cc nh qun l cp trn v nhng ngi ng u cc

bphn chc nng chuyn mn nhm tranh thti a squan tm, ng hca

cp trn, ngi ng u trong vic ginh ngun lc cn thit cho hot

ng ca dn.

- Knng tip thv quan hkhch hng: Mt trong nhng nhim vquan

trng nht ca nh qun l dn l trgip cc n v, doanh nghip trong

hot ng Marketing. Lm tt cng tc tip thsgip n vgic khchhng hin ti, tng thm khch hng tin nng.

- Knng ra quyt nh: La chn phng n v cch thc thc hin cc

cng vic dn l nhng quyt nh rt quan trng, c bit trong nhng iu

kin thiu thng tin v c nhiu thay i, bin ng. ra c quyt nh

ng v kp thi cn nhiu knng tng hp ca nh qun l nh: knng t

chc bao gm lp khoch, xc nh mc tiu, phn tch; knngxy dng

nhm nh thu hiu, thc y, tinh thn ng i v knng cng nghlin

quan n kinh nghim, kin thc vdn.


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2. Qun l dn phn mm2.1Khi nim:

Qun l dn phn mm l tp hp cc cng vic c thc hin bi mt tp th

(c thc chuyn mn khc nhau, thc hin cng vic khc nhau, thi gian thamgia dn khc nhau) nhm t c mt kt qunh dkin, trong thi gian d

kin, vi mt kinh ph d kin. Trong thut ng ca chuyn ngnh Cng ngh

phn mm, Qun l dn phn mm l cc hot ng trong lp khoch, gim st

v iu khin resources dn (v dnh kinh ph, con ngi), thi gian thc hin,

cc ri ro v quy trnh thc hin dn nhm m bo thnh cng cho dn. Qun

l dn phn mm cn m bo cn bng gia ba yu t: thi gian, resources v

cht lng. Ba yu tny c gi l tam gic dn. Ngi qun l dn phmmm gi l PM (Project Management).

2.2 Quy trnh qun l dn phn mm

Quy trnh qun l d n phn mm l quy trnh vn dng nhng kin thc, k

nng v kthut cng nghvo hot ng ca dn t c mc tiu ca d

n t ra. Nhng ng dng ny c a vo phn mm theo mt tiu chun ha

ca qun l dn theo tiu chun PMI.

m bo dn thnh cng, cc thnh vin dn phi m bo:

La chn quy trnh ph hp t c mc tiu ca dn

Tun theo cc yu cu p ng c nhu cu v mong i ca cc bn lin

quan.

Cn bng c cc yu cu (nhn t) cnh tranh trong dn nh: phm vi cng

vic, ngn sch, tin , cht lng, ri ro, thay i. Ty theo quy m ca tng d

n m cc mi giai on li c thgm nhng quy trnh nhhn.


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Ngoi cc li ch chin lc nu trn phn mm cn cung cp y cc tnh

nng hthng. Vic bo mt c tin hnh mt cch tuyt i nghim ngt. Vic

phn quyn c cthn tng vai tr ca ngi sdng.

1. Khi to dn (Initiating): Giai on ny thc hin vic nh ngha mt dnmi hoc mt pht sinh (hoc trn ln) mi ca mt dn c sn nh: Xc nh

yu cu ca dn, mc u tin ca dn, phn tch cc yu cu u t, phn

cng trch nhim cho cc bphn trin khai.

2. Lp khoch dn (Planning): Giao on ny yu cu thit lp phm vi cng

vic ca dn, iu chnh li mc tiu v xc nh ng i ti mc tiu .

3. Trin khai (Executing): Giai on ny thc hin hon thnh cc cng vic cxc nh trong phn lp khoch m bo cc yu cu ca dn.

4. Gim st v kim sot (Monitoring & Control): Giai on ny yu cu vic theo

di, r sot v iu chnh li tin v khnng thc hin ca dn. Theo di cc

ri ro, thay i, pht sinh trong qu trnh thc hin v c nhng xut iu chnh

kp thi.

5. Kt thc (Closing): Giai on ny thc hin kt thc tt ccc hot ng ca

dn chnh thc ng li dn.

Thc tFsoft-FPT c 3 giai on:

+ Planning: Giai on ny ouput ra l: Work Order (WO), Projec Planning (PP)

+ Monitoring: Giai on iu hnh, gim st v thc hin d n. Tracking task

member, tracking time, management change request, manage risk, issues.

+ Closing: Collect data, Milestone report, PostMortem report. Meeting nh gi

dn, a ra cc lesson, practices ca dn, nh gi members.


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Hnh 1: Cc giai on trong qun l phn mm(Fsoft-FPT)

Hnh 2: Cc hot ng chnh trong giai on planning (Fsoft-FPT)


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2.3 Cc hot ng chnh trong qun l dn phn mm

2.3.1 Xc nh yu cu

Trc tin, cn xc nh cc yu cu chc nng (cng vic phn mm thc hin)

cng nh phi chc nng (cng nghdng pht trin phn mm, sdng tronghiu hnh) ca phn mm. Tip theo cn xc nh r resources cn thit xy

dng phn mm. Resources y c th gm c nhn t con ngi, cc thnh

phn, phn mm c thsdng li, cc phn cng hoc cng cc sn cn dng

n; trong nhn tcon ngi l quan trng nht. iu cui cng l xc nh

thi gian cn thit thc hin dn. Trong qu trnh ny cn phi nm bt c

bi ton thc tcn gii quyt cng nh cc hot ng mang tnh nghip vca

khch hng c thxc nh r rng yu cu chung ca n, xem xt dn ckhthi hay khng.

Cn xc nh c r requirements ca khch hng, t bit c cc product

s delivery l g? V d d n c phm v tdesing coding- test th sn phm

release phi bao gm cc ti liu ca design, cc file test case (UTC), cc file test

report (UTR), source code (Software pakacge).

Ngoi ra cng ty thuc vo yu cu nhn sn phm ca khch hng, c th sthm cc yu cu release khc nh:

+ Understading document: Ti liu nghin cu, tm hiu chc nng

+ Release report: bn bo co chi tit effort cho mi giai on lm dn, design

bao nhiu, study bao nhiu, coding bao nhiu, test bao nhiu, management bao

nhiu.

Trong qu trnh lm d n, khch hng s c mt s Change request (CR) v

ngi qun l cn phi bit qun l nhng CR ny trnh bqun cc yu cu

mi thay i .


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2.3.2 Vit n (Work order)

Vit n l qu trnh xy dng ti liu m tn xc nh phm vi ca d

n, trch nhim ca nhng ngi tham gia dn; l cam kt gia ngi qun l d

n, ngi ti trdn v khch hng. Ni dung ca ti liu m tn thng c

nhng ni dung sau: [cn dn ngun]

Bi cnh thc hin dn: Cn cphp l thc hin dn, hin trng cng ngh

thng tin ca khch hng trc khi c d n, nhu cu ng dng phn mm ca

khch hng, c im v phm vi ca phn mm sxy dng.

Mc ch v mc tiu ca dn: xc nh mc ch tng th, tin hc ha hot

ng no trong quy trnh nghip vca khch hnh, xc nh mc tiu ca phn

mm gm lng dliu xl, li ch phn mm em li.

Phm vi dn: Nhng ngi lin quan ti dn, cc hot ng nghip vcn tin

hc ha.

Ngun nhn lc tham gia dn: Cn bnghip v, ngi phn tch, ngi thit

k, ngi lp trnh, ngi kim th, ngi ci t trin khai dn cho khch hng,

ngi hng dn khch hng sdng phn mm, ngi bo tr dn phn mm.

Rng buc thi gian thc hin dn: Ngy nghim thu dn, ngy bn giao d

n.

Rng buc kinh ph: Kinh ph trong tng giai on thc hin dn.

Rng buc cng nghpht trin: Cng nghno c php sdng thc hin

dn.

Chk cc bn lin quan ti dn.

Trong quy trnh ca Fsoft-FPT: PM l ngi to ra cc n (WO) sau gi b

phn QA review, nu khng c phn hi g th s ngi lnh o cp cao hn

approved ti liu .


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2.3.3 Lp khoch dn (Project Planning)

Lp khoch thc hin dn l hot ng din ra trong sut qu trnh tkhi bt

u thc hin dn n khi bn giao sn phm vi nhiu loi khoch khc nhau

nhm htrkhoch chnh ca dn phn mm vlch trnh v ngn sch. Ban

u l Project planning. Trong qu trnh lm c thm lp khoch qun l CRs, k

hoch qun l time, khoc qun l task (MS Microsoft Project), Khoch qun

l Risks, Issues.

Cc loi khoch thc hin dn

Khoch m bo cht lng: M tcc chun, cc qui trnh c sdng trong

dn. Cc chsnh bt c bao nhiu li trn sdng code vit c. Review

code cn bt c bao nhiu, review test case cn bt c bao nhiu. Execute test

bt c bao nhiu li. Tt ccc mertrics lin quan cht lng dn u c

planning trong giai on u.

Khoch thm nh: M tcc phng php, ngun lc, lch trnh thm nh h

thng.

Khoch qun l cu hnh: M tcc thtc, cu trc qun l cu hnh c s

dng.

Khoch bo tr: Dtnh cc yu cu vh thng, chi ph, n lc cn thit cho

bo tr.

K hoch pht trin i ng: M tk nng v kinh nghim ca cc thnh vin

trong nhm dn spht trin nh thno.

Quy trnh lp khoch thc hin dn

Thit lp cc rng buc ca dn: thi gian, nhn lc, ngn sch

nh gi bc u vcc "tham s" ca dn: quy m, phc tp, ngun lc


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Xc nh cc mc thi gian trong thc hin dn v sn phm thu c ng vi

mi mc thi gian

Trong khi dn cha hon thnh hoc cha bhy bth thc hin lp i lp li

cc cng vic sau:

Lp lch thc hin dn

Thc hin cc hot ng theo lch trnh

Theo di stin trin ca dn, so snh vi lch trnh

nh gi li cc tham sca dn

Lp li lch thc hin dn cho cc tham smi

Tha thun li cc rng buc v sn phm bn giao ca mi mc thi gian

Nu c vn ny sinh th xem xt li cc k thut khi u a ra ccbin

php cn thit

Cu trc khoch thc hin dn

Tchc dn

Phn tch cc ri ro(risk): vi cc risk c ln khoch dtnh sc

th cn c c chqun l, c cc bin php phng nga, c lng chi ph

gii quyt nu c xy ra, don nu risk xy ra th c nh hng ti

vic Timeliness ca dn hay khng.

Yu cu vti nguyn phn cng, phn mm

Phn cng cng vic(Task list)

Lp lch dn

C chkim sot v bo co.


18/37



III. KHI NIM V LOGIC M1. Tng quan vLogic m

Trong cuc sng hin i logic mc ngha g khng ?? Cu trli l c.Hin

nay logic mc gn cht vi cuc sng ca chng ta cthl ng dng ca nc sdng trong hu ht cc gia dng nh ni cm in,my git,my ht

biN ng mt vai tr cc k quan trng gip cho cuc sng hin i pht

trin.

Lgic m (ting Anh: Fuzzy logic) c pht trin t l thuyt tp m thc

hin lp lun mt cch xp xthay v lp lun chnh xc theo lgic vtcin.

Lgic mc thc coi l mt ng dng ca l thuyt tp mxl cc gi tr

trong thgii thc cho cc bi ton phc tp (Klir 1997).

Lgic mcho php lin thuc c gi trtrong khong ng 0 v 1, v hnh

thc ngn t, cc khi nim khng chnh xc nh "hi hi", "gn nh", "kh l" v

"rt". Cth, n cho php quan hthnh vin khng y gia thnh vin v tp

hp. Tnh cht ny c lin quan n tp mv l thuyt xc sut. Lgic m

c a ra ln u vo nm 1965 bi GS. Lotfi Zadeh ti i hc California,

Berkeley.

2. Khi nim tp mMt tp hp trong mt khng gian no , theo khi nim cin schia khng

gian thnh 2 phn r rng. Mt phn t bt k trong khng gian s thuc hoc

khng thuc vo tp cho. Tp hp nh vy cn c gi l tp r. L thuyt tp

hp cin l nn tng cho nhiu ngnh khoa hc, chng tvai tr quan trng ca

mnh. Nhng nhng yu cu pht sinh trong khoa hc cng nh cuc sng chothy rng l thuyt tp hp cin cn phi c mrng.

Ta xt tp hp nhng ngi tr. Ta thy rng ngi di 23 tui th r rng l tr

v ngi trn 55 tui th r rng l khng tr. Nhng nhng ngi c tui t23

n 55 th c thuc tp hp nhng ngi trhay khng? Nu p dng khi nim


19/37



tp hp cin th ta phi nh ra mt ranh gii r rng v mang tnh cht p t

chng hn l 43 xc nh tp hp nhng ngi tr.

Nh vy nhu cu mrng khi nim tp hp v l thuyt tp hp l hon ton t

nhin. Cc cng trnh nghin cu v l thuyt tp m v logic m cL.Zadeh cng bu tin nm 1965, v sau lin tc pht trin mnh m.

nh ngha:Cho khng gian nn U, tp A U c gi l tp mnu A c

xc nh bi hm A :X->[0,1].

A c gi l hm thuc, hm lin thuc hay hm thnh vin (membership

function)

Vi xX th A (x) c gi l mc thuc ca x vo A.

Nh vy ta c thcoi tp r l mt trng hp c bit ca tp m, trong hm

thuc chnhn 2 gi tr0 v 1.

K hiu tp m, ta c cc dng k hiu sau:

Lit k phn t: gi s U={a,b,c,d} ta co th xc nh mt tp mA=

dcba

02.03.01.0

A = Uxxx A |)(, A =

Ux

A

x

x)(trong trng hp U l khng gian ri rc

A =U

A

xx /)( trong trng hp U l khng gian lin tc

Lu l cc k hiu v khng phi l cc php tnh tng hay tch phn, m

chl k hiu biu thtp hp m.

Cc khi nim lin quan:


20/37



GisA l tp mtrn v trU, c hm thuc A th ta c cc khi nim sau:

Gi ca A, k hiu supp(A) l mt tp r bao gm tt ccc phn txUsao cho A (x) > 0

Nhnca A l mt tp r bao gm tt ccc phn txU sao cho A (x) = 1 Binca A l mt tp r bao gm tt ccc phn txU sao cho 0 < A (x) [0,1] cho bi cng thc C(a) = 1 a, a [0,1]. Khi

hm thuc ca phn b chun trthnhA

(x) = C( A (x)). Nu tng qut ho

tnh cht ca hm C th ta sc tng qut ho nh ngha ca phn b m. T

ta c nh ngha:

Phn b mca tp mA l tp m A vi hm thuc c xc nh biA

(x) =

C( A (x)), trong C l mt hm sthocc iu kin sau:

i. Tin C1 (iu kin bin): C(0) = 1, C(1) = 0ii. Tin C2 (n iu gim): a, b [0,1]. Nu a < b th C(a) C(b)

Hm C thocc iu kin trn c gi l hm phn b.

Ta thy rng hm thuc ca phn b chun l mt hm c bit trong hcc hm

phn b.

V d:

Hm phn b Sugeno C(a) =a

a

1

1 trong l tham s tho > -1. Hm b

chun l trng hp c bit ca hm Sugeno khi = 0.

Hm phn b Yager C(a) = wwa1

)1( trong w l tham s thow > 0. Hm b

chun l trng hp c bit ca hm Yager khi w = 1.

3. Bin ngn ngTa xt mt bin nhn gi trtrong mt min gi trno , chng hn nhit

c thnhn gi trsl 1 C, 2 C, l cc gi trchnh xc. Khi , vi mt gi

trcthgn vo bin sgip chng ta xc nh c tnh cht, quy m ca bin.


23/37



Ngoi ra chng ta cn bit c nhng thng tin khc lin quan n bin . V d

chng ta hiu l khng nn chm tay trn vo vt c nhit l 80 C tr ln.

Nhng trong thc tth chng ta thng ni khng nn chm vo vt c nhit

cao cht khi ni khng nn chm vo vt c nhit l 80 C trln. Thc t

l li khuyn u th c ch hn bi v nu nhn c li khuyn sau th ta db

ngnhn l c thchm tay vo vt c nhit l 79 C trong khi vt c nhit

80 C trln th khng. Nhng vn t ra l nu nghe theo li khuyn u

th ta c thxc nh r l nhit bng bao nhiu th c thchm tay vo? Cu

trli l tuvo kin ca tng ngi. Vi nhit l 60 C th c ngi cho l

cao trong khi ngi khc th khng. Tuy cc kin l khc nhau nhng c mt

iu chc chn l khi gi tr ca bin nhit cng tng th cng ddng cchp nhn l cao. Nh vy nu xt hm cao nhn bin nhit v trvtl

kin ng l cao th cao sl hm thuc ca tp mnhit cao trn v

trnhit

Bin nhit c thnhn gi trcao l mt gi trca ngn ngtnhin nn nc gi l mt bin ngn ng(linguistic variable)

Khi nim bin ngn ng c Zadeh a ra nm 1973 nh sau:

Mt bin ngn ngc xc nh bi b(x, T, U, M) trong :

1

0.9

10050 80

Nhit

cao

120


24/37



x l tn bin. V dnhit , tc , m, T l tp cc tl cc gi trngn ngtnhin m x c thnhn. V dx ltc th T c thl {chm, trung bnh, nhanh}

U l min cc gi trvt l m x c thnhn V dx l tc th U c thl {0km/h,1km/h, 150km/h}

M l lut ngngha, ng mi ttrong T vi mt tp mAt trong U

Tnh ngha trn chng ta c thni rng bin ngn ngl bin c thnhn gi

trl cc tp mtrn mt v trno .

Mnh m:

Trong logic cin (logic vtcp mt), mt mnh phn tP(x) l mt pht

biu c dng x l P trong x l mt i tng trong mt v trU no tho

tnh cht P. V dx l schn th U l tp cc snguyn v P l tnh cht chia

ht cho 2. Nh vy ta c thng nht mt mnh phn tx l P vi mt tp

(r) A = xU | P(x) .

T ta c:

P(x) = (x)

Trong l hm c trng ca tp A ( xA (x) = 1). Gi trchn l ca

P(x) chnhn mt trong hai gi tr1 v 0 (true v false) tng ng vi skin x

thuc A hoc khng

Trong trng hp P l mt tnh cht mchng hn nh sln th ta sc mt

mnh logic mphn t. Khi tp hp cc phn t trong v trU thoP l

mt tp mB c hm thuc B sao cho:

P(x) = B (x)


25/37



Lc ny P(x) c thnhn cc gi trtu trong [0,1]. V ta thy c thng nht

cc hm thuc vi cc mnh logic m.

Cc php ton mnh m:

Trong logic cin, tcc mnh phn tv cc php ton (AND), (OR),

(NOT) ta c thlp nn cc mnh phc. Ta c:

P(x) = 1P(x)

P(x) Q(y) = min(P(x), Q(y))

P(x) Q(y)=max(P(x), Q(y))

P(x)=>Q(y) = P(x) Q(y) = max(1-P(x), Q(y))

P(x)=>Q(y) = P(x) (P(x) Q(y)) = max(1-P(x), min(P(x), Q(y)))

Nh vy, ta sc mrng mt cch tnhin tlogic cin sang logic mvi

quy tc tng qut ho dng hm b mcho php phnh, hm T-norm cho php

giao v S-norm cho php hp. Smrng ny da trn stng quan gia mnh

logic mvi hm mv cc php ton trn tp m. Ta c:

A (x) = C( A (x))

A (x) B (y) = T( A (x), B (y))

A (x) B (y) = S( A (x), B (y))

A (x) => B (y) = S(C( A (x)), B (y)) (1)

A (x) => B (y) = S( C( A (x)), T( A (x), B (y)) ) (2)

Trong C l hm b m(hay phnh m), T l hm T-norm, S l hm S-norm.

Cc hm ny trnh by trong phn php ton trn tp m.

Php ton ko theo mlut if-then mthng dng:


26/37



Cc php ton ko theo c vai tr quan trng trong logic m. Chng to nn cc

lut mthc hin cc php suy din trong tt ccc hm. Do mt mnh

m tng ng vi mt tp mnn ta c thdng hm thuc thay cho cc mnh

.

Sau y l mt sphp ko theo quan trng c sdng rng ri:

Php ko theo DienesRescher

Nu p dng cng thc (1) vi S-norm max v C l hm b chun cho ta c php

ko theo DienesRescher

A (x) => B (y) = max(1- A (x), B (y))

Php ko theo Lukasiewicz

Nu p dng cng thc (1) vi S-norm l hm hp Yager vi w=1 v C l hm b

chun cho ta c php ko theo Lukasiewicz:

A (x) => B (y) = min(1, 1- A (x)+ B (y))

Php ko theo Zadeh

Nu p dng cng thc (2) vi S-norm l max, T-norm min hoc tch v C l hm

b chun cho ta c php ko theo Zadeh:

A

(x) => B

(y) = max( 1- A

(x), min( A

(x), B

(y))) (a)

A (x) => B (y) = max( 1- A (x), A (x). B (y)) (b)

Ko theo Mamdani


27/37



Ta c thcoi mnh A (x) => B (y) xc nh mt quan h2 ngi R UxV.

Trong U l khng gian nn ca x (v trcha x), V l khng gian nn ca y (v

tr cha y). Khi gi tr chn l ca mnh A (x) => B (y) l gi tr hm

thuc ca cp (x,y) vo R. Theo cng thc xc nh hm thuc ca quan hmtac

A (x) => B (y) = T( A (x), B (y))

Trong T lmt T-norm. Khi chn T l min hoc tch ta c cc php ko

theo Mamdani:

A (x) => B (y) = min( A (x), B (y)) (a)

A (x) => B (y) = A (x). B (y) (b)

Lut modus-ponens tng qut:

Tng tlogic cin, trong logic mcng c lut modus-ponens nh sau:

GT1 (lut) : if x l A then y l B

GT2 (skin) : x l A

--------------------------------------------------------

KL : y l B

Trong A, B, A, B l cc bin ngn ng(c ngha l cc tp m).

Cng thc tnh kt lun ca lut modus-ponens nh sau:

'B (y) = supx

T( R (x,y), 'A (x)) (*)

Trong T l mt hm T-norm v R l quan hhai ngi xc nh bi php ko

theo. Cch tnh R (x,y), chnh l cch tnh gi trchn l ca php ko theo trnh


28/37



by phn trc. Nh vy tutheo cch chn cch tnh lut ko theo khc nhau

m ta c cch tnh kt quca lut modus-ponens khc nhau.

V d: Gisquan hgia nhit v p sut cho bi lut sau:

Nu nhit lcao th p sut lln.

Nhit nhn cc gi trtrong U = {30, 35, 40, 45}

Ap sut nhn cc gi trtrong V = {50,55,60,65}

Ta c cc tp mxc nh bi cc bin ngn ngnhit v p sut nh sau:

A = nhit cao = 451

40

9.0

35

3.0

30

0

B = p sut ln =65

1

60

1

55

5.0

50

0

p dng lut ko theo Mamdani tch ta c quan hmsau (gi trdng i, ct j l

gi trhm thuc ca cp nhit i v p sut j vo quan h)

R=

65605550

45

40

35

30

115.00

9.09.045.00

3.03.015.00

0000

By gi, gista bit skin nhit l trung bnh v

A = nhit trung bnh =45

1.0

40

8.0

35

1

30

6.0

p dng cng thc (*) ta suy ra B =65

8.0

60

8.0

55

45.0

50

0


29/37



4. Kin trc hmMt hmtiu biu c kin trc nh hnh v

Thnh phn trung tm ca hml c slut m(fuzzy rule base). C slut m

bao gm cc lut mif-then biu din tri thc ca chuyn gia trong lnh vc no

. Trong trng hp mt hiu khin mcthth c slut mchnh l tri

thc v kinh nghim ca cc chuyn gia trong vic iu khin khi cha p dng h

m.

Thnh phn quan trng ktip l bsuy din m(fuzzy inference engine). Nhim

vca bphn ny l kt hp cc lut trong c slut m,p dng vo tp mu

vo theo cc phng php suy din mxc nh tp mu ra.

Dliu u vo ca hiu khin ml cc tn hiu do cc bphn cm bin mi

trng cung cp sau khi sho nn c tnh cht r (khi nim r y c ngha

l cc tn hiu khng phi l cc tp m, chkhng c ngha l cc tn hiu

khng c nhiu). V vy cn phi c bmho (fuzzier) chuyn cc dliu s

u vo thnh cc tp mbsuy din mc ththao tc c.

C slutm

Bsuy

din m

Bmho B giim

u vo (s ) u vo (tp

m)

Tham kholut m

u ra (tpm)

u ra (s )


30/37



D liu u ra ca b suy din m dng cc tp m s c b gii m

(defuzzier) chuyn thnh tn hiu s trc khi truyn n cc c quan chp hnh

nh tay my, cng tc, van iu khin,

Do cc dliu u vo v u ra c sho nn ta chcn xem xt cc hmlm vic vi cc bin s. Trng hp tng qut, hmnhn mt vector n chiu

u vo v cho ra mt vector m chiu u ra. Hmnh thc gi l hm

nhiu u vo nhiu u ra (MIMO). Nu m bng 1, ta c hhmnhiu u

vo mt u ra (MISO). Mt hmnhiu u vo nhiu u ra c thphn

tch thnh nhiu hnhiu u vomt u ra. Do ta chcn tm hiu kvh

mnhiu u vomt u ra vi cc bin s. Khi chni vhmnhiu - mt

th ta sngm hiu l mt hmnhiu u vomt u ra vi cc bin s

K hiu , trong l min xc nh ca cc bin vo i, i=1..n v V l min gi

trca bin ra y, ta c m hnh hmnhiu u vomt u ra nh hnh v:

Hm

nhiu u vo

mt u ra

1Ux

2Ux

nUx

Vy


31/37



5. Bsuy din mCc lut if-then c thc p dng bng cc cng thc tng qut nh trnh

by trong chng logic mnhng trong thc t th thng c tnh bng cng

thc Mamdani max-min hoc max-tch (max-prod) . Chng ta sxem xt kkin

trc b suy din m s dng phng php suy din max-min. Khi chuyn qua

phng php suy din max-tch th ch cn thay min bng php nhn trong cc

cng thc.

Cho A, A, B ln lt l cc tp mtrn v trX, X, Y. Lut if A then Bc th

hin nh mt quan hmR=AB trn XY. Khi tp mB suy ra tA c

xc nh bi:

'B (y) = max {min [ 'A (x), R (x,y)]} (*)

Trng hp mt u vo v mt lut:

Ta c 'B (y) = maxx

{min [ 'A (x), R (x,y)]} = maxx

{min [ 'A (x),

A (x), B (y)]}

= min {maxx (min [ 'A (x), A (x)]), B (y)}

= min {maxx

AA' (x), B (y)}

= min { h AA' , B (y)}

Trong h AA' l cao ca tp mAA

B

BA A

h

x

y


32/37



Trng hp hai u vo v mt lut

y l trng hp lut c pht biu Nu x l A v y l B th z l C.

Lut: Nu x l A v y l B th z l CS kin: x l A v y l B

-------------------------------

Kt lun: z l C

Lut mvi iu kin c 2 mnh nh trn c thbiu din dng AxB => C.

Suy lun tng ttrng hp mt u vo v mt lut ta c:

'c

(z) = min { h AxBxBA ''

,C

(z)}

M A x B A x B = (A A) x (B B) nn h AxBxBA '' = min {h AA' ,h BB' }

Vy 'c (z) = min { h AA' ,h BB' , C (z)}

Suy rng ra cho trng hp nhiu u vo Ai, i=1..n v mt lut

Lut: Nu x1 l A1 v x2 l A2 v... v xn l An th z l CS kin: x1 l A1 v x2 l A2 v... v xn l An

-------------------------------

Kt lun: z l C

'c (z) = min { (ni ..1

min h AiiA ' ), C (z)}

Minh ha:

h1

A A

x

C

C

z

B B

y

h2


33/37



Trng hp nhiu u vo v nhiu lut:

Trong trng hp nhiu u vo v nhiu lut, ta tnh kt quu ra cho tng lut

sau kt quca hsl cc php giao hoc hp cc kt quring ty theo

bn cht ca hl hi hay tuyn cc lut.

Nu trong mt lut c dng Nu x l A hoc y l B th z l C ta tch thnh 2 lut

ring bit Nu x l A th z l C v Nu y l B th z l C tnh.


34/37



IV. NGHIN CU P DNG LOGIC M TRONG PHNTCH D N PHN MM

Khi nhn c request cng vic ca khch hng v cng vic. Khch hng s

thm d vestimate chi ph ca chng ta. Nu chi ph ph hp vi qungn sch

ca h th h sng . Nhng estimate li l mt vic khng hn gin. N

c coi l vic au u kh khn nht ca nhng ai lm dn ni chung v dn

phn mm ni ring. c im cng vic, phm vi cng vic, cng nghsdng

ca n l g, ngn ng, framework l g, mc kh d, yu tcon ngi hin c,

tnhng yu tchng ta cn nhc n o a ra con sestimate effort sau cho

khch hng ng m chng ta vn c li nhun.

Khi khch hng ng v k hp ng vi chng ta. Nhng ngi qun l phn

mm squyt nh mdn. Ngi PM slm Project Planning. lm Project

Planning th PM cn c kinh nghim lm dn. Nu dn quen thuc th sda

trn nhng con sthng k ca dng dn . Nhng nu dn l mt lnh vc

hon ton mi lth cn phi tham kho nhiu ngun khc nhau, nhiu dng dn

khc nhau. Project Planning gm cc chsca dn, s lng effort, s lng

ngi lm, thi gian lm bao lu, cc con s m bo cht lng nh Bug

Code/KLOC, Bug Test/KLOC, con scam kt vProductivity, size ca dn(tnh

bng KLOC), don nhng risk c thxy ra, ra cc chin lc m bo cht

lng dn, CSS, Timeliness.

Sau y l mt sv dlin quan n vic phn tch, don cc chslin quan

trong qu trnh lm dn phn mm:

V dvkho st hi lng ca khch hang (CSS), chng ta c thxy dng

c bin ngn ngV vi bba nh sau:

V=CSS l tn bin

U l tp cc s nguyn ch ra im ca khch hng nh gi. U=

{1,2,..,50,.80,.100}


35/37



Tv ={Khng hi lng, Hi lng, Rt hi lng}

Cc tp con mKhng hi lng, Hi lng, Rt hi lng c nh ngha bi

cc hm thuc fKhng hi lng , fHi lng , fRt hi lng nh sau:

fKhng hi lng = 1 if u


36/37



2/ kh ca khi lng yu cu khng r rng

3/ Thi gian phn tch, Q&A khch hng

4/ Mc xy ra risk ca dn.

Sau chng ta xc nh gi trca cc ngn ngtrn ty thuc vo vic a ra

cc gi trca dn. V d: Khi lng yu cu khng r rng (10%, 20%, 30%

ca ton bcc yu cu khch hng trong dn). kh ca khi lng yu cu

khng r rng(1,3,5, 7 l trng sca cc mc kh)

Chng ta cng c thxy dng cc lut mlin quan qun l dn phn mm. V

dnh: Nu risk xy ra th thi gian can thip thno l tt nht, vi risk c trng

scao th cn thi gian l bao nhiu, bin php trnh v xl nh thno.

Nu yu cu ca khch hng c phm vi nh hng rt rng th thc hin test th

no l


37/37


V.KT LUNti tm hiu nhng khi nim c bn ca Qun l dn, quy trnh lm dn

phn mm. Tm hiu v tham kho quy trnh thc ttrong Fsoft-FPT.

ti cng tm hiu cc khi nim ca Logic m, cc nh ngha, xy dng tng p dng Logic mvo phn tch mt svn lin quan qun l dn

phn mm.

Tuy nhin do thi gian nghin cu, phm vi ca mn hc nn ti chdng li

mc xy dng tng, thu thp d liu. Cha xy dng pht trin ra mt

chng trnh ng dng. S lng thut ton nghin cu cn t. Hng pht trin

ca ti l xy dng c nhiu hn na cc bin ngn nglin quan trong qunl dn phn mm, xy dng c b suy din m, chng trnh demo a ra

c nhng kt qunh gi phn tch dn nhanh v chnh xc.

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LOGIC MỜ TRONG PHÂN TÍCH DỰ ÁN PHẦN MỀM