Gene a ion o es cases om unc ional
equi emen s. A su ey
Ja ie J. Gu ié ez, Ma ía J. Escalona, Manuel Mejías, Jesús To es
Depa men o Compu e Languages and Sys ems
Uni e si y o Se ille
{ja ie j, escalona, iso o, j o es}@lsi.us.es
Abs ac :
One o he majo quali y c i e ia o a so wa e sys em is how well i ul ils he
needs o use s o cus ome s. One echnique o e i y and imp o e he g ade o
ul ilmen is sys em es ing. Sys em es cases migh be de i ed om he
equi emen s o he sys em unde es . This pape p esen s he esul s o a
su ey among 13 app oaches o d i e he gene a ion o es cases om
unc ional equi emen s.
1. In oduc ion
So wa e es ing is becoming mo e complex day by day. This complexi y
en o ces using echniques and me hods o assu e so wa e quali y. One
o his me hods is sys em es ing. The main goal o sys em es ing is o
e i y ha equi emen s a e success ully implemen ed in o sys em unde
es . In o de wo ds, sys em es ing assu es ha so wa e sys em does
wha i is expec ed o do.
The main a e ac s o ob ain sys em es cases a e he own
equi emen s o he sys em unde es [Be olino04]. This p ocess migh
be d i en by sys ema ic me hods and ools.
Since 2003, we ha e been s udying and compa ing exis ing
app oaches o de i e es cases om he unc ional speci ica ion o he
sys em unde es . A p elimina y abs ac o ou su ey was p esen ed in
SV04 [Gu ie ez04]. In his pape we p esen a mo e comple e su ey
which alida es conclusions exposed in [Gu ie ez04] and ex ends hem.
Nowadays, use cases a e widely used o de ine unc ional equi emen s
[Escalona04], so bo h e ms a e synonymous in his pape .
This wo k is o ganized as ollows. Sec ion 2 desc ibes al eady analyzed
app oaches. Sec ion 3 iden i ies he sol ed and unsol ed aspec s in he
p ocess o gene a ion o es cases. Finally, sec ion 4 exposes
conclusions and u u e wo k.
2. S a e o he a
The e a e se e al app oaches o de i e es cases om unc ional
equi emen s when hose equi emen s a e exp essed in a o mal and
p ecise no a ion, like Z o algeb aic speci ica ions. Howe e , mos o he
so wa e indus y wo ks wi h equi emen s in na u al languages. Templa e
and abula models, like he ones in oduced by [Cockbu n00] o
[Escalona04], a e widely used o de elop all kind o sys ems.
This su ey is ocused on app oaches ha s a om unc ional
equi emen s exp essed in na u al language, gene ally as use cases.
Ac ually, we only know wo epo s ha analyse and compa e app oaches
o gene a e sys em es cases om equi emen s. The i s epo
[Denge 03] (called Denge om he e on) analyses 12 app oaches. The
second epo is his su ey i sel (called Gu ie ez om he e on), which
analyzes 13 app oaches (lis ed in able 1). Fi e o hose app oaches a e
also analyzed in Denge epo (Id 1, 3, 7, 8 and Ca ego y Pa i ion in 11).
Addi ional app oaches included in Denge epo a e lis ed in able 2.
Those app oaches a e qui e simila o he ones in able1, so, hey ha e
been omi ed.
Id Yea Ti le Re e ences
1 1997 So wa e Requi emen s and Accep ance Tes ing. [Hsia95], [Hsia97]
2 2000 Au oma ed Tes Case Gene a ion om Dynamic Models [F öhlich00]
3 2000 Ex ended Use Case Tes Design Pa e n [Binde 00]
4 2001 Requi emen Base Tes ing [Mogyo odi02], [Mogyo odi03]
5 2002 A UML-Based App oach o Sys em Tes ing [Labiche02]
6 2002 Tes Cases om Use Cases [Heumann02]
7 2002 Tes ing F om Use Cases Using Pa h Analysis Technique [Na esh02]
8 2002 Use Case De i ed Tes Cases. [Wood02]
9 1999 Scena io-Based Valida ion and Tes o So wa e [Glinz99] , [Ryse 03]
10 2003 Requi emen s by Con ac [Nebu 03]
11 2003 PLUTO & Ca ego y Pa i ion Me hod [Os and88], [Be olino03],
[Be olino04]
12 2004 De i a ion o Domain Tes Scena ios om Ac i i y
Diag ams. [Rude 04],
[Rude 04-2]
13 2004 Requi emen s o Tes ing in a Na u al Way [Boddu04]
Table 1: App oaches analyzed in Gu ie ez Repo .
Ou p e ious pape includes ou app oaches. Only wo o hem (id 6
and id 9 in able 1) ha e been included in he inal e sion o he su ey.
An app oach omi ed is UML-Based S a is ical Tes Case Gene a ion due
we ha e ocused only on unc ional e i ica ion. Ano he omi ed app oach
is AGEDIS [Ha man04], since a u he in es iga ion and con e sa ion
wi h hei au ho s shows us ha i is ocused on design models and ha i
equi es he sys em buil . Howe e , AGEDIS pape s a e a good sou ce o
ideas.
Yea Au ho s Ti le Re e ence
1998
Meye S. Sand oss R. Applying Use-Case Me hodology o SRE and
Sys em Tes ing.
STAR Wes Con e ence.
1999 Ca pen e P.B. Ve i ica ion o Requi emen s o Sa e y-C i ical
so wa e.
SIGAda'99. Redondo Beach CA.
USA.
1999 Colla d R. Tes Design: De eloping Tes Cases om Use
Cases.
So wa e Tes ing & Quali y
Enginee ing Magazine.
1999 Cunning S.J. Rozenbli
J.W.
Tes Scena io Gene a ion F om a S uc u ed
Requi emen Speci ica ion.
IEEE Enginee ing o Compu e
Based Sys ems.
2000 Hindel B. Hehn U. Cons uc ing Tes Cases om De i ed
Requi emen s.
Eu oSPI.
2002
Blacbu n M. Busse R.
Nauman A.
In e ace-D i en Model-Based Tes Au oma ion. In e na ional Con e ence on So .
Tes ing Analysis & Re iew
2002 Pudipeddi H.V. Unde s anding, Designing and Tes ing Use Cases. h p://www.s ickyminds.com
Table 2: App oaches analyzed in Denge Repo .
App oaches analyzed in Gu ie ez epo can be di ided in o h ee
g oups (shown in igu e 1) due o hei no a ion o modelling sys em
beha iou . The i s g oup de i es es cases di ec ly om equi emen s in
na u al language. The second g oup builds a model om he unc ionali y
and de i es es cases om ha model. A e ac s used o exp ess he
beha iou o he sys em a e lis ed in able 4. The hi d g oup is based on
he Ca ego y-Pa i ion echnique. Two app oaches join echniques om
he wo g oups. App oach [Boddu04] builds s a e machines om
equi emen s in na u al language as a i s s ep o de i e es cases.
App oach [Rude 04] builds an ac i i y diag am anno a ed wi h ca ego ies
and pa i ions.
Figu e 1: Techniques o modelling he beha iou o he sys em.
The e a e also di e ences among he a e ac s needed o gene a e es
cases. Some app oaches s a om use cases desc ibed wi h UML Use
Case diag am [UML03] and comple ed wi h empla es in na u al
language. O he app oaches include hei own elici a ion phase, so hei
s a ing poin is a se o needs om he use s. One app oach needs use
cases and addi ional in o ma ion, like class diag ams and sequence
diag ams. A classi ica ion is shown in igu e 2.
Figu e 2: A e ac s needed o gene a e es cases.
The esul s ob ained om he app oaches ha e been classi ied in o 2
g oups ( igu e 3). The i s g oup deno es ha de i ed es cases a e
exp essed like ac ions o e he sys em in na u al language o decision
ables (like [Binde 00]). Those es cases mus be implemen ed by hand.
The second g oup allows us o ob ain es sc ip s. Howe e , hey used
comme cial o expe imen al ools, no a ailable. In some cases, he
Ca ego y-Pa i ion me hod can gene a e execu able esul s, as desc ibed
in [Balce 89].
Figu e 3: Resul s ob ained om each app oach.
The e a e se e al app oaches ha men ion a suppo ing ool. A
classi ica ion is shown in igu e 4. The only ool eely a ailable ha we
ha e ound is a suppo ing ool o [Nebu 03] app oach.
Many o he analyzed app oaches include he gene a ion o expec ed
esul s. Howe e , in all o he app oaches, his ac i i y is de eloped by
hand, using he c i e ion o he es e s.
Figu e 4: Suppo ing ools.
Denge and Gu ie ez analyses ha e simila conclusions al hough
Gu ie ez epo is wo yea s olde han he Denge epo . The main
conclusion o Denge epo is ha app oaches wo k a a heo e ical le el
wi hou desc ibing how o gene a e execu able es cases. Denge epo
exposes ha he e is oom o mo e app oaches o sol e he oubles and
he lacks de ec ed in he exi ing ones. The conclusions a Gu ie ez epo
exposes ha new app oaches ha e he same lacks han he ones
analyzed in Denge . The e is a lack o documen a ion, case s udies, and
a ailable suppo ing ools. These ac s make ha d he applica ion o
heses app oaches o e eal p ojec s.
3. Resol ed and un esol ed aspec s
A e analyzing and compa ing app oaches lis ed in able 1, we ha e
ex ac ed which aspec s a e ea ed sa is ac o ily and which aspec s need
a u he de elopmen . Those aspec s a e lis ed in able 3 and desc ibed
in he ollowing pa ag aphs.
Resol ed aspec s Un esol ed aspec s
• Building beha iou al mode.
• Suppo ing ools.
• Two le els in es cases de i a ion.
• De ini ion o equi emen s
• Documen a ion and p ac ical cases.
• No measu e o e ec i eness and quali y.
• Lack o sys ema iza ion and au oma ion.
• Tes case implemen a ion.
• Lack o empi ical s udies.
Table 3: Resol ed and un esol ed aspec iden i ied.

As seen in igu e 1, en app oaches de elop a beha iou al model o
exp ess he unc ionali y expec ed in he sys em unde es . The no a ions
used a e lis ed in able 4.
Re e ence Beha iou al model
[Hsia97] Scena io ees and ini e s a e machines.
[F öhlich00] Fini e s a e machines.
[Mogyo odi03] Cause-e ec diag ams.
[Labiche02] UML ac i i ies and sequence diag ams.
[Na esh02] Ac ion- low diag am.
[Nebu 03] Use cases anno a ed wi h p econdi ion, pos -condi ions and in a ian s.
[Ryse 03] Own Use cases execu ion model (simila o FSM).
[Os and88], [Be olino04] Ca ego ies, choices and es ic ion.
[Rude 04] UML ac i i y diag am anno a ed wi h ca ego ies, choices and es ic ion.
[Boddu04] Fini e s a e machine.
Table 4: Techniques o gene a e beha iou al model.
The use o beha iou al models allows sys ema ize and au oma e he
p ocess. A widely used echnique in es ing is called model-based es ing
[Be olino04-2]. Tes ing app oaches based on model-based es ing migh
also be applied o de i e sys em es cases om beha iou al models.
The exis ence o suppo ing ools can be classi ied as a esol ed bu
also as an un esol ed aspec . Se en o he app oaches analyzed ha e a
suppo ing ool. This ac is a g ade o hei ma u i y and imp o es hei
au oma ion. Howe e , an un esol ed aspec is o allow he access o
hese ools by ee o open-sou ce licences o , a leas , in es iga ion
licences, like AGEDIS p ojec .
An aspec disco e ed, is ha i is necessa y o de i e wo le els o es
cases. I is well known in code es ing ha es sepa a e componen s o
agmen s o code es ed wi h uni es cases do no gua an ee he p ope
ope a ion o he sys em [Cohen04]. Thus, an addi ional in eg a ion es ing
phase which e i ies ha each componen wo ks success ully in
collabo a ion wi h o he componen s is needed. This philosophy can be
also applied o sys em es ing. Sys em es ing can be di ided in o wo
s ages. The i s s age e i ies he beha iou o each use case in isola ion
(simila o code uni es ing). The second s age e i ies ha use cases
wo k p ope ly oge he and sa is y unc ional equi emen s (simila o
code in eg a ion es ing). Bo h s ages can be combined in o de o ob ain
es cases ha combine se e al equi emen s and se e al execu ion
pa hs o each equi emen . Howe e , he e a e only 2 app oaches (id 6
and 10 in able 1) ha include dependences o use cases and de i e es
cases ha in ol e se e al use cases. So, his s age has o be s udied
deeply o new app oaches.
An impo an aspec is how o de ine a use case o de i e a se o es
cases o m i . Mos o he app oaches indica e he in o ma ion ha a use
case has o include o be use ul in es case de i a ion. As he e is no a
s anda d widely accep o de ine use cases, his aspec is esol ed
enough.
The e a e also se e al aspec s ha we es ima e ha hey a e s ill
un esol ed. Those aspec s a e lis ed in Table 3. The i s aspec is he
lack o documen a ion. All app oaches ha e li le o incomple e echnical
documen a ion. Many app oaches do no e e o any p ac ical applica ion
o ealis ic case s udy. Bo h ac s obs uc eal applica ion o hose
app oaches.
An aspec al eady o go en by all app oaches is o p opose me ics and
ools o e alua e he quali y o gene a ed es cases. We assume ha all
app oaches s a om he assump ion ha , i hei s eps a e success ully
applied, a se o es cases wi h he maximum co e age a e ob ained.
Since he e a e se e al decisions ha es ing eam has o adop , a me ic
o e alua e how hose decisions a ec o co e age is needed. This aspec
is also ela ed o he absence o empi ical s udies abou e ec i eness o
each app oach. None o he au ho s demons a ed wi h expe imen s ha
hei app oach is be e han andom es ing o han using common
sense.
Co e age c i e ion in he app oaches analyzed (excep in [Binde 00]) is
mainly based in a combina ional explo a ion o all possible scena ios om
a use case. Some app oaches, like [Rude 04], [Nebu 03] o [Na esh02],
include se e al co e age app oaches (like all- ansi ion o all-s a es) o
minimize he combina ional explosion.
The implemen a ion o es cases is also an aspec b ie ly (o omi ed)
desc ibed in he analyzed app oaches. The wo app oaches ([Rude 04]
and [Boddu04]) ha de i e execu able es sc ip s need ools no
a ailable. As seen in igu e 3, many app oaches jus only gene a e ex ual
desc ip ion o es cases in na u al language. Addi ional and non- i ial
s eps ha e o be pe o med o implemen hose es cases in o execu able
sc ip s o code.
4. Conclusions
The main conclusion is ha he e a e enough app oaches o acqui e
p ecise ideas on how o de i e es cases. Howe e , he e is s ill no a
comple e and in eg a ed app oach ha desc ibes he whole p ocess.
F om his su ey, i is concluded ha he mos -used echnique is model-
based es ing. This echnique is being used mo e and mo e e e y day in
he so wa e indus y. Model-based es ing is success ully applied and
documen ed when i is applied o design models o when models a e
ex ac ed om code. Ou u u e wo k is o de elop a model-based es ing
app oach om unc ional equi emen . This app oach has o be able o
de i e es cases om ea ly de elopmen phases, allowing imp o e
quali y equi emen s and minimizing ime and e o used in sys em
es ing [Dahls ed 05].
The inc easing numbe o analyzed app oaches, om 4 o 13, has
con i med he p elimina y conclusions p esen ed in [Gu ie ez04]. None o
he app oaches is he de ini e one. Wi h hei s udy as a whole se , we
ha e exposed i s esol ed and un esol ed aspec s, so he e is a gasp o
a new app oach which uses he esol ed aspec and co ec s he
un esol ed ones.
Numbe Task
1 Build beha iou al model.
2 De i e es scena ios om one use case.
3 De i e es scena ios om se e al use cases.
4 Gene a e es alues.
5 Ob ain es scena ios.
6 Reduc ion he numbe o es s cases wi hou los o co e age.
7 Measu e o co e age.
8 Gene a e expec ed esul s.
9 So es cases o maximize a selec ed c i e ion ( es scena io p io i ize).
10 Build es sc ip s o execu able es code.
Table 5: Tasks o gene a e es cases om use cases.
In pape [Gu ie ez04], we exposed, as u u e wo k, he de elopmen o
a new me hodology. Nowadays, we ha e de ined he scope o he new
app oach om he conclusions ob ained om Gu ie ez epo . The scope
o ou app oach is lis ed in able 5.
Ac i i y App oach
1 App oaches lis ed in able 4.
2 All app oaches
3 [Labiche02], [Nebu 03]
4 App oaches based in CP me hod [Be olino04], [Rude 04], [Os and88]
5 [Labiche02]
6 [Na esh02]
7 [Binde 00]
8 No app oaches
9 [Na esh02]
10 No app oaches
Table 6: App oaches ha men ioned s eps lis ed in able 5.
Compa ing he aspec s exposed in sec ion 3 wi h asks lis ed in Table
5, we ha e de ined he g ade o ma u i y and co e age o each ask om
exi ing app oaches. Resul s a e lis ed in able 6.
Some p elimina y pape s and se e al cases o s udy ha e been
de eloped. Howe e , none o hem ha e been published ye .
Re e ences
[Balce 89] Balce M. J., Hasling W. M., Os and T. J. 1989. Au oma ic
Gene a ion o Tes Sc ip s om Fo mal Tes Speci ica ions. ACM, pp
210- 218. USA.
[Be olino03] Be olino, A., Gnesi, S. 2003. Use Case-based Tes ing o
P oduc Lines. ESEC/FSE’03. Helsinki, Finland.
[Be olino04] Be olino, A., Gnesi, S. 2004. PLUTO: A Tes Me hodology
o P oduc Families. Lec u e No es in Compu e Science. Sp inge -
Ve lag Heidelbe g. 3014 / 2004. pp 181-197.
[Be olino04-2] Be olino A., Ma che i E., Faedo A. 2004. In oducing a
Reasonably Comple e and Cohe en App oach o Model-based
Tes ing. TACoS'04 P elimina y Ve sion.
[Be olino04] Be olino, A., Gnesi, S. 2004. PLUTO: A Tes Me hodology
o P oduc Families. Lec u e No es in Compu e Science. Sp inge -
Ve lag Heidelbe g. 3014 / 2004. pp 181-197.
[Binde 00] Binde R. V. 2000. Tes ing Objec -O ien ed Sys ems. Addison-
Wesley. USA.
[Boddu04] Boddu R., Guo L., Mukhopadhyay S. 2004. RETNA: F om
Requi emen s o Tes ing in Na u al Way. 12 h IEEE In e na ional
Requi emen s Enginee ing RE’04.
[Cockbu n00] Cockbu n, A. 2000. W i ing E ec i e Use Cases. Addison-
Wesley 1s edi ion. USA.
[Cohen04] Cohen, F. 2004. Ja a Tes ing and Design. F om Uni Tes ing
o Au oma ed Web Tes s. P en ice Hall. USA.
[Dahls ed 05] Dahls ed , Å. (2005) Guidelines Rega ding Requi emen s
Enginee ing P ac ices in o de o Facili a e Sys em Tes ing. 11 h
In e na ional Wo kshop on Requi emen s Enginee ing. Po o, Po ugal.
[Denge 03] Denge C., Medina M. 2003. Tes Case De i ed om
Requi emen Speci ica ions. F aunho e IESE Repo .
[Escalona04] Escalona M.J. 2004. Modelos y écnicas pa a la
especi icación y el análisis de la Na egación en Sis emas So wa e. Ph.
Eu opean Thesis. Depa men o Compu e Language and Sys ems.
Uni e si y o Se ille. Se ille, Spain.
[F öhlich00] F öhlich, P, Link, J. 2000. Au oma ed Tes Case Gene a ion
om Dynamic Models. ECOOP 2000. pp. 472-491.