Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja Sotware Relablty Idex Reasoable Allocato Based o UML 1 esheg Hu, 2 M.Zhao, 3 Jaeg Yag, 4 Guorog Ja 1, Frst Author College o Computer Scece &Iormato, Guzhou Uversty, Guyag 550025, Guzhou, Cha. hwsgzsz@yahoo.com.c *2,Correspodg Author College o scece Guzhou Uversty, Guyag 550025, Guzhou, Cha. gudaee@hotmal.com 3 College o Computer Scece &Iormato, Guzhou Uversty, Guyag 550025, Guzhou, Cha. yt232@126.com 4 Commercal College o Guzhou, Guyag 550004, Guzhou, Cha. 715044371@qq.com Abstract I ths paper we troduce a methodology that starts wth the aalyss o the UML use case dagram or sotware relablty allocato wth the probablty o executg each use cases. e wll utlze the executg probablty o each use cases to measure the mportace o the use case, the to determe weght actor o each use case. Fally, we ca allocate the relablty dex value to each class accordace wth sequece dagram ad class dagram. Because class s the smallest ut OOD, the relablty dex value allocated to each class s oud out, we ca determe that each developer should udertae how much relablty tas durg developmet process. Keywords: UML, Use Case, Sequece Dagram, Class Dagram, Sotware Relablty, Allocato 1. Itroducto The am o sotware relablty allocato s that the sotware relablty dex ca be reasoably allocated to the correspodg sotware compoets or sotware uts [1]. Sotware developmet resources ca be reasoably utlzed ad developers ca ow that they must udertae the resposblty or sotware relablty by sotware relablty allocato. Curretly, the sotware relablty allocato s maly based o the mportace or complexty o each uty o sotware [2][3][4][5]. Sotware relablty ca be allocated by usg qualtatve method or quattatve method. The data o quattatve method s dcult to obta. Geerally, we use the qualtatve method to allocate the relablty o sotware system. The qualtatve method maly measure mportace ad complexty o each module o sotware system. As complexty s related to coecto relatoshp betwee modules, t s very dcult to calculate [2][3][4]. The popular method o sotware relablty allocato s based o the mportace o each module, where modules are descrbed as the smallest ut the sotware developmet process. The class s the smallest ut OOD. The basc dea about sotware relablty allocato s show Fgure 1. Fgure 1. Sotware Relablty Allocato Process. The process o sotware relablty allocato ca be oud rom Fgure 1. It s that the goal o sotware relablty ca be proposed by system aalyst. The sotware relablty dex ca be reasoably allocated to each module by system archtect. So t s very mportat that developers uderstad the archtecture o sotware. UML s a very good way to uderstad the archtecture o sotware. The UML models ca comprehesvely descrbe sotware system rom a dyamc ad statc Joural o Covergece Iormato Techology(JCIT) Volume 7, Number 23, Dec 2012 do : 10.4156/ct.vol7.ssue23.21 178
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja perspectve [6]. UML use case dagram belogs to statc perspectve o UML, whch cludes system boudary, all ds o use cases, actors ad the relatoshps betwee use cases ad actors. To acheve a use case eed a seral o obects to teract wth each other, ths stuato ca be descrbed sequece dagrams. UML class dagram ca descrbe all classes o system ad these classes teract wth each other. So the relablty dex allocato ca be acheved by UML OOD, as show Fgure 2. Fgure 2. Relablty Allocato Based o UML I ths paper, we propose a eectve method o relablty allocato based o UML. Ths method ca allocate the relablty dex o sotware system rom each use case to each class by UML use case dagram, sequece dagram, class dagram. Fally, we ca ow each class o sotware system to udertae relablty tas. The relablty dex value o each class calculated by ths method ca become the bass o sotware qualty maagemet, ad t s also the bass o relablty testg. The paper s orgazed as ollows: Secto 1 troduces some bacgroud owledge. Secto 2 dscusses allocato strategy o sotware system relablty based o UML use case dagram. Secto 3 dscusses allocato strategy o sotware system relablty based o UML sequece dagram. Secto 4 dscusses allocato strategy o sotware system relablty based o UML class dagram. Coclusos ad uture drectos are dscussed Secto 5. 2. Relablty allocato based o UML use case dagram 2.1. Aotatg UML use case dagram The UML models ca comprehesvely descrbe sotware system rom a dyamc ad statc perspectve. A use case dagram cludes system boudary, all ds o use cases, actors ad the relatoshps. The appearace probablty o actors ad the usg probablty o use cases ca be aotated UML use case dagrams(readers terested UML bascs ca reer to [7][8]),as show Fgure 3. Fgure 3. Aotated Use Case Dagram 179
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja I UML use case dagram, the probablty p( UC X ) o executg the use case x ca be gured out by [7][8]: p( UC ) p * p (1) X 1 here p s the appearace probablty o -th actors (or groups o users, each sharg smlar system usage patters). p represets the usg probablty that the -th actor requests the -th use case. s the umber o user types. 2.2. Determg the mportace o varous use cases The mportace o varous use case s determed by ts executg probablty. Geerally, the use cases wth hgher executg probablty are more sgcat or customers. Each use case has ts ow correspodg weght actor o the mportace ad s sorted the weght actor cormed by ts executg probablty. There are two ways to determe the weght actor: oe way s that the sotware relablty s regarded as desred value o the sotware system, ths way, the weght actor o use case wth the hghest executg probablty s deed as the maxmum oe, the we determe ad desced the weght actor o other use cases tur. Aother way s that the sotware alure rate s regarded as desred value o the sotware system, the weght actor o use cases wth the executg probablty s deed as the mmum oe, that s, the smaller the weght actor s, the hgher the mportace o use case s. Ad the we determe ad asced the weght actor o other use cases tur. Accordg the executg probablty o use cases, the experts ca determe mportace weght actor o each use case, ad the we ca sort them rom small to large. The calculato process s the ollowg: e assume that w represets the mportace weght actor o the -th use case, p( UC ) represets the executg probablty o the -th use case ater sortg, rato represets the derece betwee the executg probablty o the rst use case ad the secod use case ater sortg, that s: rato p( UC ) p( UC ) (2) 1 2 Assume that w 1 s the mportace weght actor o the use case wth the hghest executg probablty (that s the rst use case ater sortg, Here t s w1 1 ) ad w 2 s the mportace weght actor o the use case wth the secod hghest executg probablty (Here t s w ).The derece o mportace weght actor betwee use cases s the ollowg: 2 3 w [( w w )*( p( UC ) p( UC ))] / rato (3) 2 1 1 Importace weght actor o each use case rom thrd use case s the ollowg: w w w (4) 1 2.3. Determg the relablty dex o each use case At rst, the relablty goal value o sotware must be determed, assumed t s R. The to determe the total umber o use cases, or example, we assume that there are use cases sotware 180
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja system, w (=1,2,,) s the mportace weght actor o each use case. Fally, the relablty dex value R allocated to each use case ca be calculated, as show ormula (5). R * R 1 (5) I the relablty goal value o sotware system s the total alure rate, the the alure rate allocated to each use case s, as show ormula (6). 1 * (6) 3. Relablty allocato based o UML sequece dagram 3.1. Aotatg UML sequece dagram UML sequece Dagram ca descrbe that obects teract wth each other to complete the ucto o use cases use case dagram [6]. Sequece dagram descrbes ths relato o teracto as a twodmesoal graph. The vertcal drecto s the tmele. The lele o the obects wll exted dow alog the tmele. The horzotal drecto represets the role o the depedet obects, the role o the obects ca be descrbed as lele, whe the obect exsts, ths lele s descrbed as dotted le, t represets that the role o obect s ot actve, whe the role o obect s actve. The lele s descrbed as a dual-chael le. The arrows sequece dagram ca be descrbed the message rom the lele o oe obect to aother obect. These arrows arrage rom top to bottom chroologcal sequece the sequece dagram. he the obect accepts the servce message that other obect requests, we cosder ths obect as busy. Each use case use case dagram ca acheve ts ucto by mutual teracto betwee the obects oe or more o the sequece dagram. e assume that the umber o sequece dagram or the -th use case s s( ), ( ) s the requecy o the -th sequece dagram reerrg to the -th use case(where s( ) 1 ( ) 1). Hece, we ca obta the ollowg equato: p( ) p( )* ( ) (7) here p( ) s the probablty o the -th the sequece dagram reerrg to the -th use case. 3.2. Determg the allocato relablty dex o each sequece dagram reerrg to the use case The weght actor o each sequece dagram ca be calculated accordace wth secto 2.2. The allocato relablty dex o -th use case s R that ca be calculated by equato (5). Assume that s the weght actor o the -th sequece dagram reerrg to -th use case. Hece, we ca calculate the allocato relablty dex o the -th sequece dagram reerrg to -th use case rom the ollowg equato: 181
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja R 1 * R (8) I the relablty goal value o sotware system s the total alure rate, the we ca calculate the allocato alure rate o -th sequece dagram reerrg to -th use case rom the ollowg equato: 1 * (9) 3.3. Idety the executo probablty o each compoet sequece dagram The executg probablty o the compoets or obects sequece dagram s rato betwee the umber o ts busy perods ad the total umber o busy perods reerrg to all compoets or obects [6]. The specc stuato s show Fgure 4. Fgure 4. Aotated Sequece Dagram. N : It represets the total umber o busy perods o the all compoets or obects the -th sequece dagram reerrg to the -th use case. c N :It represets the umber o busy perods o the oly compoet c or obect c the -th sequece dagram reerrg to the -th use case. Pc ( ) :It represets the executg probablty o the compoet c or obect c the -th sequece dagram reerrg to the -th use case. It s gve by: c N Pc ( ) (10) N 3.4. Determg the allocato relablty dex o each compoet or obect sequece dagram The weght actor o each compoet or obect sequece dagram ca be calculated accordace wth the executg probablty o each compoet or obect ad the way that has bee descrbed 182
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja secto 2.2. The allocato relablty dex case ca be calculated by equato (8). Assume that R o the -th sequece dagram reerrg to the -th use c s the weght actor o the compoet c or obect c -th sequece dagram reerrg to -th use case. Hece, we ca calculate the allocato relablty dex o the compoet c or obect c -th sequece dagram reerrg to -th use case rom the ollowg equato: R c 1 c c * R (11) I the relablty goal value o sotware system s the total alure rate, the we ca calculate the allocato alure rate o the compoet c or obect c the -th sequece dagram reerrg to -th use case rom the ollowg equato: 4. Relablty allocato based o UML class dagram c 1 c c * (12) 4.1. The troducto o UML class dagram The class dagram o UML ca descrbe statc structure o sotware archtecture. The basc ut o composto o the class dagram s class ad relatoshp betwee classes. The class dagram s basc to buld the other UML dagrams, there s ot class dagram, the other UML dagram caot be descrbed. The obect reerrg to class class dagram ca occur more sequece dagrams. Fgure 5 s a UML class dagram. There are sx relatoshps a UML class dagram. They are geeralzato, realzato, depedecy, assocato, aggregato, composto. The stregth order o the varous relatoshps: geeralzato, realzato, composto, aggregato, assocato, depedecy [6]. Fgure 5. UML Class Dagram. 183
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja 4.2. Determg the allocato relablty dex o each class sequece dagram Each class class dagram ca appear more sequece dagrams. So The allocato relablty c dex R o the compoet or obect c the -th sequece dagram reerrg to the -th use case ca be calculated by equato (11) or equato (12). Assume that there are use cases sotware system, there are 1 sequece dagrams the rst use case, there are 2 sequece dagrams the secod use case, ad so o. Hece, the allocato relablty dex R( c ) o the compoet c or obect c reerrg to class class dagram s the total sum o the allocato relablty dex each sequece dagram. It s gve by: R( c ) R (13) 1 1 c I the relablty goal value o sotware system s the total alure rate, the we ca calculate the allocato alure rate ( c ) o the compoet c or obect c reerrg to class class dagram s the total sum o the allocato alure rate each sequece dagram. It s gve by: ( c ) (14) 1 1 c 5. Cocluso UML s curretly the most popular sotware modelg laguage. A correct UML use case dagram ca accurately relect the all ds o sotware requremets requremet speccatos [6][9]. The allocato relablty dex value o each use case ca be calculated by ts executg probablty. Ths value ca provde a good reerece or ollow-up phase o sotware developmet. The sequece dagram relects the teracto betwee compoets or obects by message commucato to acheve the ucto reerrg to use case. The allocato relablty dex value o each compoet or obect ca be calculated by coutg the umber o ther busy perods sequece dagram. These compoets or obects ca be oud reerrg to class dagram. So ths paper we use the UML use case dagram, sequece dagram ad class dagram to gradually decompose the relablty dex value o sotware system, the to determe how much each class should be udertoo the tas o relablty, ad ally to specy how much resposblty each developer should udertae or relablty o sotware system. 6. Reereces [1] Su zheg-a, Pe xao-q, Sog x, Da zhog a, Sotware Relablty Egeerg, BEIHANG UNIVERSITY PRESS, Cha, 2009. [2] Jaguo Ja, Yu Yag, Tao Yag, Feg Zhag, Guodog Yu, Research o Dyamc Programmg o the Seres Mauacturg System Relablty Allocato, JCIT: Joural o Covergece Iormato Techology, Vol. 7, No. 7, pp.17-25, 2012. [3].Kuo, R.a, Recet Advaces Optmal Relablty Allocato, IEEE Tras. o Ma ad Cyberetcs, Part A:Systems ad Humas, vol. 37, pp.143-156, 2007. [4] B.Yag, H.J.Hu, S.H.Guo, Cost-Oreted Tas Allocato ad Hardware Redudacy Polces Heterogeeous Dstrbuted Computg System Cosderg Sotware Relablty, Computers ad Idustral Egeerg,vol.56, pp.1687-1696, Apr.2009. [5] A. Mettas, Relablty allocato ad Optmzato or Complex Systems, Proc. Relablty ad Mataablty Symposum, pp.216-221, 2000. [6] Has-Er Ersso, Magus Peer, Bra Lyos, Davdo Fado, UML Toolt, Publshg House o Electrocs Idustry, Cha, 2004. 184
Sotware Relablty Idex Reasoable Allocato Based o UML esheg Hu, M.Zhao, Jaeg Yag, Guorog Ja [7] H. Sgh, V. Cortellessa, B. Cuc, E. Guel, ad V. Bharadwa, A bayesa approach to relablty predcto ad assessmet o compoet based systems, I Proc. O 12th Iteratoal Symposum o Sotware Relablty Egeerg (ISSRE 01), pp.12-21, 2001. [8] Vttoro Cortelessa, Harshder Sgh, Boa Cuc, Early relablty assessmet o UML based sotware models, OSP 02, Rome, Italy, pp.302-309, July 24-26, 2002. [9] esheg Hu, Zhouhu Deg, Y Hog, A Method o FTA Base O UML Use Case Dagram, The Proceedgs o 9th Iteratoal Coerece o Relablty, Mataablty ad Saety ( ICRMS 2011), pp.757-759, Jue 12-15,2011,Cha. [10] Jaeg Yag, Ru ag, Zhouhu Deg, esheg Hu. eb Sotware Relablty Aalyss wth Yamada Expoetal Testg-Eort. The Proceedgs o 9th Iteratoal Coerece o Relablty, Mataablty ad Saety ( ICRMS 2011), pp.760-765, Jue 12-15,2011, Cha. [11] Lbo Fa, Zhgag Ma, Tedecy Aalyss o Sotware Relablty Egeerg, The Proceedgs o 9th Iteratoal Coerece o Relablty, Mataablty ad Saety ( ICRMS 2011), pp.771-774, Jue 12-15, 2011, Cha. [12] Chage Ma, Guochag Gu, Jg Zhao, Improved Neural Networ based o Dyamc Predcato Model o Sotware Relablty, JCIT: Joural o Covergece Iormato Techology, Vol. 6, No. 7, pp.349-357,2011. [13] Xu Ja, Ya Ha, L Qamu, A Methodology or Sotware Relablty Rs Assessmet, JCIT: Joural o Covergece Iormato Techology, Vol. 6, No. 4, pp.188-200, 2011. [14] Che Yu, Yu Yag, Lu Zhzhog, She Juy, Sematc Servce Dscovery Based o QoS Otology, Joural o Next Geerato Iormato Techology, Vol. 2, No. 2, pp.89-96,2011. [15] S.Yacoub, B.Cuc, ad H.Ammar, Scearo-based relablty aalyss o compoet-based sotware, I Proc. O 10th Iteratoal Symposum o Sotware Relablty Egeerg(ISSRE 99), 1999. [16] M.Ge, Y.Yu. Sot Computg Approach or Relablty Optmzato:State-o-the-Art Survey, Relablty Egeerg & System Saety, vol. 91, pp.1008-1026, Sep. 2006. [17] R.L.Bul ad C.Y.Lu, Optmal allocato o redudat compoets or large systems, IEEE Tras. Relablty, vol. R-34, pp.241-247,1985. [18] Amar SV, Duga JB, Msra RB(1999), Optmal relablty o systems subect to mperect aultcoverage, IEEE Trasactos o Relablty 48:275-284. [19] Mchael R. Lyu, Sampath Ragaraa, Aad P.A.va Moorsel, Optmal Allocato o Test Resources or Sotware Relablty Growth Modelg Sotware Developmet, IEEE TRANSACTIONS ON RELIABILITY, vol.51, NO.2, JUNE 2002. 185