6 Giai doan 2 Phan tich he thong - Ch6 Chuyen sang thiet ke he thong

8/14/2019 6 Giai doan 2 Phan tich he thong - Ch6 Chuyen sang thiet ke he thong

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Ch ng 6. Chuy n sang thi t k h th ng 2006 1Nguy n Trung Tr c- Khoa CNTT

Giai on 2Phn tch h thng

Chng 6

Chuyn sang thi t kh thng


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Ni dung

nh gi cc gi i php ph n mm v ccchin lc pht trin.u im v nhc im gia vic t phttrin phn mm v vic mua/ch nh sa mtgi phn mm.Ti nguyn bn ngoi v cc ng dngcho ngi s dng.Cc bc mua v nh gi mt gi phnmm.RFP v RFQ .Ti liu cc yu c u h thng v trnh by

cho ban qu n l.


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Ni dung

Chuyn t phn tch sang thi t k.S khc bit gia thit k lun l v thit

kvt l.Tm quan tr ng ca vic lm bn mu; ccphng php lm b n mu, cc cng c

v k thut.Qu trnh thit k h thng v cc h ngdn thit kh thng.To v s dng cc m thch h p trongqu trnh thit kv pht trin h thng.


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Gii thiu

Chng ny trnh by cc cng vi c cnli trong giai on phn tch h thng

nh gi cc gi i php khc nhau.Chun b ti liu yu cu h thng.Trnh by cho ban qu n l.


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nh gi cc gi i php phn mm

Quyt nh t pht trin hoc mua ph nmm

Phn mm t pht trinc pht trin bi phng CNTT ca cng ty.

Gi phn mmc mua ho c thu t cc hng ho c nhcung c p phn mm.ng dng ngang.ng dng dc.


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Hnh 6.1. Da vo gii php no c chn, cng ty c th t phttrin h thng hoc mua v c th chnh sa gi phn mm thng

mi.


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T pht trin phn mmdeveloping software in-houseCc l do t pht trin phn mm:

Tha mn cc yu c u ring bit.Gim thiu cc thay i trong cc chnh sch vcc th tc nghip vTha mn cc rng bu c ca h thng hin ti.Tha mn cc rng bu c ca cng ngh hin ti.Pht trin cc ti nguyn v cc n ng lc bntrong.


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Mua gi phn mm purchasing a software packageCc l do mua gi ph n mm:

Chi ph thp hn.Thi gian c c nhanh h n. tin cy v cc chu n hiu sut c kimtra.t nhn vin pht tri n k thut.Cc nng c p trong tng lai c cung c p tnh cung c p.Cc cng ty khc c xem l cc ti nguyn.


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Chnh sa gi phn mmcustomizing software packageMua gi phn mm c bn c th chnhsa nhm tha mn cc yu c u.Thng lng vi nh cung c p phn mm thc hin cc ph n m r ng nhm thamn cc yu c u .Mua gi phn mm v t chnh sa.


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Nh cung cp dch v ng dngCung cp cc ng dng bng cch tr ph sdng hoc lph.

Dch v cung c p c gi l applicationhosting .Cho thu cc ng dng.

Ti nguyn bn ngoioutsourcing S dng cc cng ty bn ngoi x l mtphn ti lm vic, ngn hn hoc di hn.K kt vi cc hng nhn s .Cc hng qu n l h thng hoc qun lphng tin.


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H thng ca ngi s dng cui cngend-user systemS dng cc ph n mm nghip v chun.C th cung c p cc gii php n gin, chiph thp.

Ngi s dng c th thit k cc biu munhp d liu v cc bo co ring.


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Chn gii php phn mmQuyt nh s nh hng n cc giai oncn li ca SDLC .Cng vic ca ngi phn tch h thng phthuc vo gii php c chn.


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Hnh 6.2. Tm quan tr ng ca ngi phn tch ph thuc vo giiphp no c chn.


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Cc bc nh gi v mua gi ph n mm

Qu trnh 5 bc1. nh gi cc yu c u HTTT.2. Xc nh nh cung c p phn mm c nng

lc.3. nh gi cc gi i php phn mm.

4. Mua gi phn mm.5. Ci t gi phn mm.


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Bc 1: nh gi cc yu c u HTTT.Xc nh cc tnh n ng chnh c a h thng.nh gi khi lng v s gia tng trongtng lai.M tcc rng bu c phn cng.

Chun b yu cu ngh (RFP Request For Proposal ).


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Bc 2: xc nh nh cung c p phn mmc nng lc.Bc k tip l lin h vi nh cung c p cnng lc.RFP s gip nh cung c p xc nh cc gi iphp.Cc ngun thng tin khc nhau v nh cungcp:

Ngi bn lNh sn xut my tnhBo thng mi cng nghi p hoc cc Web siteNhm t vn CNTT


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Bc 3: nh gi cc gi i php phn mm.Mc ch l so snh cc gi ph n mm vchn gi phn mm tt nht.C c thng tin t nhiu ngun.Qu trnh nh gi

C c thng tin t nhng ngi s dnghin ti.Chy kim tra ng dng .nh chun gi phn mm, nu cn.


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Bc 4: mua gi ph n mm.Bn quyn phn mm (software license ).Hp ng thu ( lease agreement ).Hp ng bo tr (maintenance agreement ).


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Bc 5: ci t gi phn mm.Thi gian ci t ph thuc vo kch c v phc tp.Tr c khi s dng gi phn mm, honthnh tt ccc bc thc hin.

Np, cu hnh v kim tra phn mm.o to nhng ngi s dng.Chuyn cc tp tin d liu thnh cc d ng thcmi.


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Nhm nh gi v ch n laMc ch ca qu trnh ny l c c snphm vi chi ph s hu thp nht.Cch tip cn nhm bo m cc yu t quantr ng u c xem xt v a ra s chnla ng n.Mc tiu chnh

nh gi cc gi i php h thng khng ch pnhn.Xp hng cc gi i php ch p nhn.Trnh by cc gi i php cho ban qu n l raquyt nh cui cng.


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Hon tt phn tch h thng

Ti liu cc yu c u h thngCn c gi l m t cc yu c u phnmm.M t cc gii php v ngh vi ban qunlTng t nh hp ng v iu s ccung c p.Phi r rng v d hiu i vi ngi sdng.


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Hon tt phn tch h thng

Trnh by cho ban qu n lNm quyt nh c th c:1. T pht trin h thng.2. Chnh sa h thng hin ti.3. Mua hoc ch nh sa gi phn mm.4. Thc hin thm cng vi c phn tch h thng.5. Chm dt ton b cng vic.


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iu ch yu l c ti liu cc yu c u hthng dhiu v chnh xc.Cc li sai, cc thi u st v cc iu mh s nh hng n cht lng ca snphm cui cng.


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Tng quan v thit kh thngThit k lun l xc nh cc tnh n ng v ccchc nng ca h thng.

Cn c gi l m hnh chnh.Thit k vt l l mt s thc hin hthng.

Mi lin hgia phn tch v thi t kGiai on thit k khng th bt u cho n

khi kt thc phn tch.Ch nn tr v giai on phn tch trong cctnh hung hn ch.

b


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Lm bn mu

Lm bn mu prototyping Lm bn mu l mt k thut thu thp thngtin.Lm bn mu h thng to ra mt m hnhlm vic vi y tnh nng ca HTTT.Cc bn mu c ch cho vi c ghi nhn ccphn ng ca ngi s dng, cc ngh ,cc i mi v cc khoch sa i.Bn mu l phin bn ca h thng c xydng nhanh.Bn mu l m hnh lm vic gip ngi sdng hiu h thng.

L b


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Lm bn mu

Lm bn muC th loi b cc vn tr c khi c phinbn cui cng.Ngi s dng c th kim tra m hnh vchp nhn hoc yu cu sa i.C th pht trin thnh phin b n cui cngca HTTT hoc c th ch c s dng xc nhn cc yu c u ca ngi s dng vb loi b sau ny.

C h i l b


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Cch tip cn lm bn mu

Thit kbn muNhm to ra bn mu thit k c ngi sdng chp nhn lp ti liu v nh chuncc tnh n ng ca h thng cui cng.C th t c d liu nhp ca ngi sdng v s chp thun ca h trong khi vntip tc pht trin h thng.

C h i l b


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Cch tip cn lm bn mu

Hnh 6.3. Sn phm cui cng ca lm bn mu l bn mu thit kc ngi s dng chp thun, trong ghi nhn cc c im

ca h thng cui cng.

L b


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Lm bn mu

Li ch ca lm bn muNgi s dng v ngi pht trin c thtrnh cc iu hiu nhm.Ngi pht trin c th to cc m t chnhxc.Ngi qun l c th nh gi m hnh lmvic.Ngi phn tch c th s dng bn mu thc hin kim tra v qu trnh o to.Lm bn mu gim r i ro xy ra cho h thngcui cng.

L b


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Lm bn mu

Cc vn tim tng ca lm bn muTc pht trin nhanh c th pht sinh ccvn vcht lng.

Cc yu cu h thng khc khng th ckim tra mt cch th a ng.Cc bn mu phc tp s khng thch ngv kh qun l.

Hn chca bn muKm hiu qu hn so vi h thng cpht trin hon ton.Tc x l chm hn v thi gian p nglu hn.C th thiu cc yu c u bo mt.

Lm bn mu


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Lm bn mu

Cc cng c lm bn muCc cng c CASE B to ng dng (application generator )B to bo co ( report generator )B to mn hnh ( screen generator )

Ngn ng th h th 4 (4GL-Fourth- Generation Language )Cc cng c lm bn mu thuc mi tr ng

thh th 4

Lm bn mu


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Lm bn mu

B to ng dngapplication generator Cn c gi l b to m lnh.Pht trin cc ch ng trnh nhanh chngbng cch chuy n t m hnh lun l tr ctip thnh m l nh 4GL.Ngn ng iu khin s kin m t cc tcvm chng trnh ph i thc hin khi xy racc s kin no .Ngn ng phi th tc khng i hi ngilp trnh vit chui lnh.Ngn ng th tc i hi ngi lp trnh tom lnh cho mi bc x l.

Lm bn mu


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Lm bn mu

B to bo coreport generator Cn c gi l b vit bo co.Thit knhanh cc bo co nh dng.C th to bo co m u xem tr c khithit kcui cng.

B to mn hnhscreen generator Cn c gi l b to biu mu.Cng cphn mm tng tc.Gip thit k giao din ngi s dng, tobiu mu mn hnh v x l cc th tc nhpd liu.

Lm bn mu


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Lm bn mu

Cc loi bn muBn mu tm thi ( patched-up prototype ).y l m hnh lm vic c tt c cc tnh n ngnhng khng hi u qu.Ngi s dng c th tng tc vi h thng.Vic lu tr v truy xut d liu c th khng

hiu qu.C thch cha cc tnh n ng c bn.Bn mu khng vn hnh c (non- operational prototpye ).y l m hnh khng v n hnh c, ngoi tr

mt s tnh nng no c kim tra.

Lm bn mu cho cc m u nhp v cc k t xut.

Lm bn mu


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Lm bn mu

Cc loi bn muBn mu lot u tin (first-of-a-series prototype )

To h thng th nghim ( pilot system ).Bn mu l mt m hnh vn hnh c.C ch khi lp k hach ci t cng mt h

thng thng tin cho nhi u ni. V d ci t,kim tra v sa i h thng cho mt ni, vsau ci t tip tc cho cc n i khc.

Lm bn mu


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Lm bn mu

Cc loi bn muBn mu c cc tnh n ng chnh (selected features prototype )

Bn mu ch c mt s tnh nng chnh c a hthng. Sau khi cc tnh n ng ny c chpnhn, b sung thm cc tnh n ng khc vo h thng.C th chy c mt s chc nng trn trnhn.H thng c xy dng theo cc n th.y l mt phn ca h thng tht.

Lm bn mu


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Lm bn mu

Hnh 6.4. Sn phm cui cng ca lm bn mu l m hnh lm vicca HTTT, sn sng cho giai on thc hin.

Cch tip cn lm bn mu


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Cch tip cn lm bn mu

Pht trin ng dng nhanhRAD -Rapid Application Development RAD l mt cc tip cn hng i tng pht trin h thng, bao g m phng phppht trin v cc cng c phn mm.RAD lin quan mt thit vi vic lm bn muh thng.Nhm RAD xcnh, phn tch, thi t kv kimtra cc b n mu.


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Ch ng 6. Chuy n sang thi t k h th ng 2006 39Nguy n Trung Tr c- Khoa CNTT Hnh 6.5. M hnh RAD ca James Martin.


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Cc s tin trnh ca h thng


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Cc s tin trnh ca h thng

Cng cm hnh ha khcS tin trnh ca h thng (systemflowchart )

Hin th qu trnh chnh v cc tc v nhp, xut.Chyu c s dng trong m hnh ha v t l.Cc k hiu khc nhau bi u din d liu hoc

cc tp tin trong mi tr ng vt l c th.Hnh dng k hiu cho bit mc ch.Cc ng c m i tn cho bit chiu i ca d

liu.


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Hnh 6.6. S dng cc k hiu chun ANSI, s tin trnh ca hthng cho th y h thng t hng x l vic tr tin ca khch hng.

Tng quan v thit kh thng


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Ngi phn tch ph i hiu ton b thit klun l tr c khi bt u thit kvt lCc bc thit kh thng.

Xem xt cc yu c u h thng.Thit kh thng

Xut (output )Nhp (input )Cc c s d liu v cc t p tinKin trc h thng

Trnh by thit kh thng.



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g q g

Mc tiu thit kh thngXy dng h thng sao cho:Hiu qu (effective )

Tin cy (reliable )Bo tr c (maintainable )



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g q g

Nghin cu thit kh thngNghin cu ngi s dngLm cho h thng thn thi n vi ngi s dng.

Lu cch ng i s dng cung c p d liu choh thng v nhn kt quxut t h thng.on tr c cc yu c u trong tng lai.

Ngi s dng HTTT Cng ty

Phi c tnh linh ng.



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g q g

Nghin cu thit kh thngNghin cu d liuNhp d liu ti ni v vo lc n xy ra.

Kim tra d liu khi nhp vo.S dng cc ph ng php nh p d liu t ngKim tra vic truy xut khi nhp d liu.Ghi nhn vic nhp hoc thay i d liu i vicc gi tr quan tr ng.Nhp d liu vo h thng ch mt ln.Trnh trng lp d liu.

Nghin cu vic x lS dng thit k n th.Thit k cc n th thc hin chc nng

n l.



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g q g

Cn nhc trong thit kCc mc ch thit k thng mu thu n vinhau.

Vic s dng d dng hn c th lm cho ccyu cu lp trnh phc tp hn.Tnh linh ng cao c th lm cho vic bo tr

nhiu hn.Tha mn cc yu c u ca ngi s dng nys kh tha mn cc yu c u ca ngi sdng khc.

Vn chnh l ch t l ng so v i chi ph

Thit kv s dng m


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g

M (code ) l mt tp cc ch v/hoc sca mt cu trc vn tt dng cho vi cphn loi cc mc d liu lu tr , linlc, x l v ly d liu.

Thit kv s dng m


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Li ch ca mTo cc danh hi u duy nht.Cho thy cc c tnh ca cc mc d liu.

Cho thy cc mi lin kt gia cc mc dliu.Gim vng nh v chi ph lu tr .

Gim thi gian nhp v truyn d liu.Thun tin cho vic phn lo i d liu.Thun tin cho vic tm kim v ly d liu.

C thhin th hoc che giu thng tin.C thgim cc li sai khi nhp d liu.Thao tc d liu mt cch hiu qu: tr n, spth t.

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Cc mc ch ca m haTheo di mt iu g (keeping track of something )

M tun t (sequence code )M dn xut (derivation code )

Phn loi thng tin (classifying information )M phn loi (classification code )M tun t chia khi (block sequence code )

Che giu thng tin ( concealing information )Mt m (cipher code )

Thit kv s dng m


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Cc mc ch ca m haThhin thng tin ( revealing information )M k s c ngh a (significant digit code / faceted code )M vit tt (abbreviation code ) / m gi nh(mnemonic code )

Yu cu mt tc v thch hp (requesting appropriate action ).M chc nng (function code ) / m tc v

(action code )

Thit kv s dng m


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M tun tsequence codeM tun t l m ly cc gi tr lin tip t tp

gi tr m.M tun t c s dng khi th t ca vicx l cn phi bit chui cc mc d liua vo h thng hoc th t ca cc s kin xy ra.

Empno Employee Name

001 Smith002 Adams003 Tiger

Hnh 6.7. Empno thuc loi m tun t.

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M tun tu im

n gin.

Ngn v duy nh t.Dpht sinh gi tr m lin tip.

Nhc imKhng cha thng tin c ch, ngo i tr th ttr c sau c a cc gi tr m.Khng linh ng.

D b trn m v cc m tr ng khng c sdng li.

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M dn xutderivation codeM dn xut l m kt hp d liu ca nhiuthuc tnh khc nhau.

Hnh 6.8. M ca ngi t mua bo c dn xut t cc thnh

phn khc nhau c a tn v a ch .

Thit kv s dng m


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M phn loiclassification codeM phn loi l m gom nhm cc m c dliu c lin quan v i nhau.

Code Tax Deduction ItemI INTEREST PAYMENTSM MEDICAL PAYMENTST TAXESC CONTRIBUTIONS

D DUESS SUPPLIES

Hnh 6.9. Gom nhm cc mc khu tr thu bng cch s dng mphn loi 1-k t.

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M phn loiPhn loi cc mc d liuPhn loi cc mc d liu l qu trnh xc nh

v gom nhm cc m c d liu thnh cc lo i(lp) da vo cc c tnh chung.nh ngh a cc lp phi thch hp vi mc chring.Phn loi cc mc d liu nhm p ng ccyu cu ca ngi s dng.Phn loi cc mc d liu phi cho php m r ng phn loi cc mc d liu mi.Cc mc d liu phi r rng.

Thit kv s dng m


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Code Tax Deductible ItemIMT

CDS

INTEREST PAYMENTSMEDICAL PAYMENTSTAXES

CONTRIBUTIONSDUESSUPPLIES

S

CIM

SUBSCRIPTIONS

COMPUTER Duplicate codesINSURANCEMISCELLANEOUS

BPNX

SUBSCRIPTIONSCOMPUTER are corrected by forcingINSURANCE the codes to fitMISCELLANEOUS

Hnh 6.10. Cc vn xy ra cho m phn lo i 1-k t khi cc loic cng k t ch.

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M tun t chia khiblock sequence codeM tun t chia khi l s m r ng ca mtun t, phn chia t p gi tr m thnh ccnhm c ngh a khc nhau.

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Range Field000 - 099 General Works List100 - 199 Philosophy, Psychology, Ethics200 - 299 Religion, Mythology300 - 399 Social Sciences400 - 499 Philology500 - 599 Science600 - 699 Applied Science700 - 799 Fine Arts

800 - 899 Literature900 - 999 History, Geography, Biography, Travel

Hnh 6.11. Phn loi thp phn Dewey s dng m khi tun t.

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Hnh 6.12. S dngm khi tun t gom nhm cc ph nmm tng t nhau.

Code Name of SoftwarePackage

Type

100 1-2-3101 Multiplan102 VP-Planner

200 R-BASE System V201 Paradox 1.1

202 dBASE III Plus 300 Wordstar 4.0301 Wordperfect 4.2

302 Word 3.1

400 Super Key 1.03401 Pro Key 4.0

Utilities

Wordprocessing

Database

Speadsheet

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Mt mcipher codeMt m l m m trong mt ch (hay mts) thay th cho mt iu g , hoc mtch thay thcho mt s.V d: ca hng bn l s dng mt t gm10 k t ch CAMPGROUND m ha gibn: C biu din 1, A biu din 2, , D biudin 0. Do , m GRAND c gi bn l

$562.90

Thit kv s dng m


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M khiblock codeM khi l m c phn chia thnh cc kh im mi khi c s phn loi ring.M k s c ngh a (significant digit code / faceted code )

Cc nhm k s ring bit biu din cc c tnhca mc d liu.Xc nh s k s cho mi c tnh.

M khi phn cp (hierarchical block code )Sp xp theo th t quan tr ng ca cc kh i.Khi bn tri l lp cha, c ngh a tng qut.Khi bn phi l lp con, c ngh a chi tit.

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Hnh 6.13. M vng in thoi (ZIP code ) l mt v d vm k sc ngh a s dng cc nhm con cho bit thng tin.

Hnh 6.14. M s dng cc k s c ngh a xc nh v tr ca mthng tn kho.


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Thit kv s dng m


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M gi nhmnemonic codeM gi nh l m s dng cc k t sv/hoc k t ch m tmc d liu.Gi tr m c tr gip gi nh.Ch s dng m gi nh khi s lng ccmc d liu khng nhi u (di 50 mc dliu). Code City

SIN SingaporeNYK New YorkHKG HongkongLON London

Hnh 6.15. M gi nh c s dng trong International Air Transport Association (IATA).

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M tc vaction codeM tc v l m cho bit tc v c thc

hin tng ng vi mc d liu.Code Action1 Delivered2 Sold3 Spoiled4 Lost or stolen5 Returned6 Transferred out7 Transferred in8 Journal entry (add)9 Journal entry (subtract)

Hnh 6.16. Mt v dvm tc v.

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M t kim traself-checking codeM t kim tra l m c ch a cc k s c

xc nh t cc k s cn li xc nh shp lca m.M t kim tra phng cc l i sai tiu biu:

Li sai do sao chp l i (transcription error ): mtk s b sai.Li sai do i ch (transposition error ): i ch2 k s lin tip.Li sai do i ch kp (double tranpositionerror ): i ch 2 k s cch nhau m t k s.Li sai ngu nhin ( random error ): nhiu k s b

sai.

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Error type Invalid ValidTranscription error 12845 12345Transposition error 783156 781356Double transposition error 301157 305117Random error 987866 987680

Hnh 6.17. Cc loi li sai.

Hnh 6.18. M 1302-6 c k s kim tra hp l. M 7198-3 c k skim tra khng h p l.

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M t kim traCc bc to cc k s kim tra (check digit )M ban u X1X2 Xn.

Chn cc tr ng sW1W2 Wn- arithmetic progression: 6 5 4 3 2- geometric progression: 32 16 8 4 2

- prime number: 17 13 7 5 3Tnh S = XiWiTnh R = S mod M, vi M l mt s nguyn t

Tnh C = M - R. Nu R = 0 th C = 0.

Thit kv s dng m


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M ban u: 12345 M = 11Arithmetic progressionS = 1 6 + 2 5 + 3 4 + 4 3 + 5 2 = 50R = S mod M = 50 mod 11 = 6

C = M - R = 11 - 6 = 5M cui cng: 12345 - 5Geometric progression

S = 1 32 + 2 16 + 3 8 + 4 4 + 5 2 = 114

R = S mod M = 114 mod 11 = 4C = M - R = 11 - 4 = 7M cui cng: 12345 - 7

Prime number

S = 1 17 + 2 13 + 3 7 + 4 5 + 5 3 = 99R = S mod M = 99 mod 11 = 0C = 0M cui cng: 12345 - 0

Hnh 6.19. V dvcc cch khc nhau to k s kim tra.

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Qu trnh thit kmXc nh cc m c d liu cn c m ha.Xc nh khi lng d liu.

Xc nh cc m c tiu ca m.Xc nh phm vi s dng m.Xc nh chu k thi gian s dng m.Xc nh loi m.

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Mt s iu lu khi thit kmCu trc m ph i tha mn cc yu c u cangi s dng v phi c phng php x

l m mt cch thch h p.Mi m phi c cu trc biu din duy nht.Thit k m phi linh ng p ng vic

thay i cc yu c u.Cu trc m ph i d hiu (n gin, thc t,c ngh a).Cn phi chun ha cc m c d liu cm ha.

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Chun ha cc m c d liu c m haTrnh cc k t m ch vit hoc pht mgn ging nhau (v d: O, Z, I, S, V c th

nhm vi 0, 2, 1, 5, U).Trnh cc l tr ng (cc gi tr m khngc s dng) trong tp gi tr m.

Cc ngy v cc tu n cn c nh s (ngy t 1 n 7, tun t 1 n 52).S dng dng 24 gi thay v dng AM/PM (vd: 13:00 thay v 01:00 PM).S dng dng ngy biu din bng cc k s thay v bng k t ch (v d: 18/09/2004 thayv 18th Sept. 2004).

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Chiu di ca mM ngn (short code )M c t k t.

Ddng phn lo i, to mt gi tr m mi.Tn t vng nh lu tr .Tn t thi gian truyn.

M di (long code )M c nhiu k t.M c thcha mt s thng tin c n thit.

Ddng cho vi c ly d liu.Ddng cho vi c x l thng tin.

Thit kv s dng m


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S dng mDuy tr m ngn gn.Cho php m r ng m.

Duy tr m n nh.To m duy nh t.S dng m c th sp th t c.Trnh nhm ln m.To m c ngh a.

S dng m cho m c ch ring bit.Duy tr cc m nht qun vi nhau.

Thit kv s dng m


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Incorrect SortingUsing

MMM-DD-YYY

Incorrect SortingUsing

MM-DD-YYYY

Incorrect Sorting(Year 2000Problem)

YY-MM-DD

Correct SortingUsing

YYYY-MM-DD

Dec-25-1998

Dec-31-1997Jul-04-1999Jun-04-1998Jun-11-2000Jun-12-1997Oct-24-1998

06-04-1998

06-11-200006-12-199707-04-199910-24-199812-25-199812-31-1997

00-06-11

97-06-1297-12-3198-06-0498-10-2498-12-2599-07-04

1997-06-12

1997-12-311998-06-041998-10-241998-12-251999-07-042000-06-11

Hnh 6.20. Cc vn sp th t d liu kiu Date .

Thit kv s dng m


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CODE DESIGN FORM

Document Reference Number: Code Design Form Number:Name of coded item: Numbering

method:Number of columns:

Check digit(Yes/No):

Number of code numbers

assignedCurrent: Future:Coding objectives:Structure:

Range of numbers:Special properties:

Period of use: Range of use:

Hnh 6.21. Mu thit km.

Documents

6 Giai doan 2 Phan tich he thong - Ch6 Chuyen sang thiet ke he thong