requirement elicitation techniques.doc

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Requirement Elicitation

Techniques

Presented to Dr. Vicki Sauter

Produced by: Ying Chen

Date: 11-08-12

Requirements engineering is branch of software Engineering concerned with the

real world goals, for Functions of and constraints on software systems. It is also

concerned with the relationship of these factors to precise specifications of software

behavior, and to their evolution over time and across software families [3]

Contents Background

Introduction

Four Methods of ommunication

on!ersational Methods

"#ser!ational Methods$

%nal&tic Methods$

'&nthetic Methods$

%d!antage and (isad!antage of Requirement Elicitation onclusion

Reference
http://www.umsl.edu/~ycnx6/#_Toc340074411http://www.umsl.edu/~ycnx6/#_Toc340074412http://www.umsl.edu/~ycnx6/#_Toc340074413http://www.umsl.edu/~ycnx6/#_Toc340074414http://www.umsl.edu/~ycnx6/#_Toc340074415http://www.umsl.edu/~ycnx6/#_Toc340074416http://www.umsl.edu/~ycnx6/#_Toc340074417http://www.umsl.edu/~ycnx6/#_Toc340074418http://www.umsl.edu/~ycnx6/#_Toc340074419http://www.umsl.edu/~ycnx6/#_Toc340074420http://www.umsl.edu/~ycnx6/#_Toc340074412http://www.umsl.edu/~ycnx6/#_Toc340074413http://www.umsl.edu/~ycnx6/#_Toc340074414http://www.umsl.edu/~ycnx6/#_Toc340074415http://www.umsl.edu/~ycnx6/#_Toc340074416http://www.umsl.edu/~ycnx6/#_Toc340074417http://www.umsl.edu/~ycnx6/#_Toc340074418http://www.umsl.edu/~ycnx6/#_Toc340074419http://www.umsl.edu/~ycnx6/#_Toc340074420http://www.umsl.edu/~ycnx6/#_Toc340074411


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Background

)o*ada&s the usage of com+uter a++lications and soft*are is increasing da& #&

da& and these s&stems +la& a !ital role in the management of #usiness e,isting

toda&- Most of the soft*are +roducts de!elo+ed toda& is to e,tend the e,isting

s&stem functionalities- (ue to the toda&.s commercial on the shelf +roducts

de!elo+ment the !ast range of fields that uses the com+uter to da&[/0] 1 different

ser!ices are e,+ected #& stakeholders1 *hich make it difficult to de!elo+ soft*are

that fulfills the e,+ectations of the users- 'ince the /24.s the de!elo+ment of

com+uters #ased s&stem has faced man& +ro#lems [/2] that leaded to too man&

+ro5ects #eing dela&ed and o!er #udget- The s&stems that *ere deli!ered also did

not meet the requirements1 or satisf& the intended +ur+ose *hich resulted in the

dissatisfaction of the users- The main reason that could #e stated for this +ro#lem is

difficulties faced in the gathering of requirements1 as requirements engineering is

the first ste+ in the soft*are de!elo+ments- 6hene!er the requirements engineers

lack the kno*ledge of the +erformance and characteristics of the different

elicitation methods1 the acti!ities related to requirements *ill fail1 thus leading to

*rong gathering of requirements that makes the *rong s+ecification documentne!er meets the stakeholder. e,+ectations and intended ser!ices- Moreo!er1 the

change in the requirements in the middle of the +ro5ect de!elo+ments +hase *ill

lead to dela& and increased cost-

Back to To+

ntroduction% ma5or goal of Requirements Elicitation is to a!oid the confusions #et*een

stakeholders and anal&sts- This *ill often in!ol!e +utting significant sort into

requirements elicitation- 7nfortunatel&1 Requirements Engineering is an immature

disci+line1 +erha+s not entirel& unfairl& characteri8ed as a #attlefield occu+ied #&
http://www.umsl.edu/~ycnx6/#_tophttp://www.umsl.edu/~ycnx6/#_top


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com+eting commercial methods1 firing com+eting claims at each other1 and lea!ing

the consumers *ear& and confused[ /]-

The goal of this +a+er is to anal&8e and com+are of the different methods of the

requirements elicitation +rocess1 *hich *ill #e useful to com+are the different

characteristics and the +erformance of the different elicitation methods- 9ence1 all

the requirement elicitation techniques are !er& hand& for e,tracting the

requirements and different organi8ations1 *hich can use different requirement

elicitation techniques according to organi8ational culture and needs-

%s requirements elicitation is a +rocess in *hich intensi!e interaction #et*een

stakeholders and the anal&sts1 so for finding the interaction #et*een stakeholders

and anal&sts *ill #e eas& for im+ro!ing the qualit& of e,tracted requirements- It is

im+ortant to distinguish different elicitation methods according to the four methods

of communication [:/]$

/- on!ersational

:- "#ser!ational

3- %nal&tic

;- '&nthetic

Each categor& +resents a s+ecific interaction model #et*een anal&sts and

stakeholders- 7nderstanding the method categor& hel+s engineers understand

different elicitation methods and guides them to select a++ro+riate method for

requirements elicitation-

Back to To+

!our "ethods o# Co$$unication

Conversational Methods


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The con!ersational method +ro!ides a means of !er#al communication #et*een

stakeholders and %nal&sts- %s con!ersation is a natural *a& of communication and

an effecti!e mean of e,+ressing needs and ideas1 and the con!ersational methods

are used massi!el& to understand the +ro#lems and to elicit generic +roduct

requirements- The on!ersational Methods are also kno*n as !er#al methods []1

such as Inter!ie*s1


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"rainstorming #$$%Brainstorming is another con!ersation method- It has some

similarities *ith *orksho+s and focus grou+s as in Brainstorming stakeholders are

gather together for a short time +eriod #ut in this short time +eriod the& de!elo+ a

large and #road list of ideas- In this meeting out >of>the>#o, thinking a++roach is

encouraged- The #rainstorming in!ol!es #oth idea generation and idea reduction-

on!ersation is one of the most +re!alent &et in!isi#le forms of social interaction-

?eo+le are usuall& ha++& to descri#e their *ork and difficulties the& face- The

!er#all& e,+ressi!e demands1 needs and constraints are often called non>tacit

requirements [13]-on!ersational methods are !er& commonl& used in requirements

de!elo+ment- 9o*e!er1 the& are la#or intensi!e [5]$ meeting setu+ and transcri+t+roducing and anal&8ing from records of a li!e interaction take time-

Back to To+

&bservational Methods

The o#ser!ational method +ro!ides means to de!elo+ a #etter understanding a#out

domain of %++lication- "#ser!ation methods *ork #& o#ser!ing human acti!ities at

en!ironment *here s&stem is e,+ected to #e de+lo&ed- In addition to state a#le

requirements1 some requirements are a++arent to stakeholders1 #ut stakeholders

find it !er& hard to !er#ali8e-

The o#ser!ation methods come into +la& *here @er#al communication #ecomes

hel+less for collecting tacit requirements- Therefore1 o#ser!ing ho* +eo+le carr&

out their routine *ork forms a means of acquisition of information *hich are hard to

!er#ali8e- The o#ser!ational methods a++ear to #e *ell suited *hen stakeholders

find it difficult to state their needs and *hen anal&sts are looking for a #etter

understanding of the conte,t in *hich the desired +roduct is e,+ected to #e used-

"#ser!ational methods is including1 'ocial anal&sis1 "#ser!ation1 Ethnogra+hic

stud&1 and +rotocol anal&sis-


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'ocial analysis, &bservation, Ethnographic study#$(% %n o#ser!er s+ends some

time in a societ& or culture for making detailed o#ser!ation of all their +ractices-

This +ractice gi!es the initial understanding of s&stem1 *ork flo* and organi8ational

culture-

)rotocol analysis#13]:In +rotocol anal&sis a stakeholder is o#ser!ed *hen he is

engaged in some task1 and concurrentl& s+eaks out loud and e,+lains his thought-

6ith the +rotocol anal&sis it is eas& to identif& Interaction +ro#lems in e,isting

s&stems and it gi!es #etter and closer understanding of 6ork conte,t and *ork

flo*-

For "#ser!ational methods1 the o#ser!er must #e acce+ted #& the +eo+le #eingstudied and the +eo+le #eing studied should carr& on *ith their normal acti!ities as

if the o#ser!er is not there-

In #oth on!ersational and "#ser!ation methods1 requirement elicitation is done #&

stud&ing some indi!iduals #ut a !ariet& of documentation ma& +ro!e out to #e

hand& for e,tracting the requirements of the desired +roduct- The documentation

ma& include +ro#lem anal&sis1 organi8ational charts1 standards1 user manuals of

e,isting s&stems1 sur!e& re+ort of com+etiti!e s&stems in market1 and so on- B&

stud&ing these documents1 engineers ca+ture the information a#out the a++lication

domain1 the *orkflo*1 the +roduct features1 and ma+ it to the requirements

s+ecification-

Back to To+

*nalytic Methods

on!ersational or "#ser!ational methods are used to directl& e,tracted

requirements from +eo+le.s #eha!ior and their !er#ali8ed thought- But still there is

a lot of kno*ledge that is not directl& e,+ressed1 for e,am+le e,+ert.s kno*ledge1

information a#out regulation and legac& +roducts are some e,am+les of such


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sources- %ll the stated sources +ro!ide engineers rich information in relation to the

+roduct- %nal&tic methods +ro!ide *a&s to e,+lore the e,isting documentation or

kno*ledge and acquire requirements from a series of deductions-it *ill include

Requirement reuse1 documentation studies1 laddering1 and re+ertor& grid [/]

Requirement reuseIn this technique1 glossaries and s+ecification of legac& s&stems

or s&stems *ithin the same +roduct famil& is used to identif& requirements of the

desired s&stem-

It has #een o#ser!ed that man& requirements in a ne* s&stem are more or less

same as the& *ere in a legac& s&stem.s requirement- 'o it is not a #ad idea to

reuse the details of requirements of an earlier s&stem in a ne* s&stem-

+ocumentation studies #%In this technique different a!aila#le documents Ae-g-

"rgani8ational +olicies1 standards1 legislation1 Market information1 '+ecification of

legac& s&stems are read and studied to find the content that can +ro!e out to #e

rele!ant useful for the requirements elicitation tasks-

-adderingThis technique can #e di!ided in 3 +arts$ creation1 re!ie*ing and

modification- Caddering method is a form of structured inter!ie* that is *idel& used

in the field of kno*ledge elicitation acti!ities to elicit stakeholder.s goals1 aims and

!alues %nal&st used laddering method to create1 re!ie* and modif& the hierarchical

contents of e,+ert.s kno*ledge in the form of tree diagram- It *as first introduced

#& the clinical +s&chologists in /24 to understand the +eo+le score !alues and

#eliefs [0-] Its success in the fields of +s&cholog& allo*s other researchers in the

industries to ada+t it in their fields- '+ecificall& soft*are de!elo+ers ha!e ada+ted

the laddering techniques for gather the com+le, user tacit requirements-

Repertory grid'takeholder is asked for attri#utes a++lica#le to a set of entities

and !alues for cells in entit& >attri#ute matri,- [/;]


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In general1 the anal&tic methods are not !ital to requirements elicitation1 since

requirements are ca+tured indirectl& from other sources1 rather than end users and

customers- 9o*e!er1 the& form com+lementar& ones to im+ro!e the efficienc& and

effecti!eness of requirements elicitation1 es+eciall& *hen the information from

legac& or related +roducts is reusa#le-

Back to To+

'ynthetic Methods

'o far1 *e ha!e discussed on!ersational1 "#ser!ational and %nal&tic methods- It is

a++arent that )o single method is sufficient enough to de!elo+ all the requirementof a s&stem- %ll these methods are good and !er& hand& in some certain conte,t

and circumstances- It is often a good idea to com#ine different elicitation methods

for de!elo+ing requirement- The com#ination hel+s the engineer unco!er the #asic

as+ects and gain a generic kno*ledge of the a++lication domain- Instead of

com#ining different of indi!idual methods1 the s&nthetic method forms a coherent

*hole #& s&stematicall& com#ining con!ersation1 o#ser!ation1 and anal&sis into

single methods- %nal&sts and stakeholder re+resentati!es communicate and

coordinate in different *a&s to reach a common understanding of the desired

+roduct- '&nthetic methods are kno*n as colla#orati!e methods as the& are

colla#oration of multi+le requirement elicitation methods- Requirement elicitation

techniques of '&nthetic methods are including scenarios1 +assi!e storoards1

+rotot&+ing1 interacti!e storoards1 D%(R%( sessions1 and onte,tual inquir& []-

'cenarios, passive storyboardsIt is an interaction session- In this session a

sequence of actions and e!ents descri#ed for e,ecuting some generic task *hich

the s&stem is intended to accom+lish- 6ith the hel+ of this technique1 clear

requirement related to +rocedure and data flo* can #e achie!ed- 6ith this

technique initial set of requirement can #e +re+ared in lesser cost-


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)rototyping, Interactive storyboardsIn this technique1 a concrete #ut +artial s&stem

is discussed *ith stakeholders- This concrete #ut +artial s&stem is e,+ected to #e

deli!ered at the end of +ro5ect- The +ur+ose of sho*ing this s&stem to stakeholders

is to elicit and !alidate functional requirement- The +

*+/R*+ sessions #$0%It stands for Doint %++lication (e!elo+mentRa+id %++lication

(e!elo+ment and em+hasi8es user in!ol!ement through grou+ sessions *ith

un#iased facilitator- D%( is conducted in the same manner as #rainstorming1 e,ce+t

that the stakeholders and the users are also allo*ed to +artici+ate and discuss on

the design of the +ro+osed s&stem- The discussion *ith the stakeholders and the

users continues until the final requirements are gathered-

Conte1tual inquiry#(%this technique is a com#ination of o+en>ended inter!ie*1

*ork+lace o#ser!ation1 and +rotot&+ing- This method used for interacti!e s&stems

design *here user interface design is critical-

%ll four requirement elicitation methods are commonl& used #ut the selection of

requirement elicitation method entirel& de+ends on the needs and organi8ational

structure- )o matter *hat de!elo+ment +ro5ect is1 requirements de!elo+ment

nearl& al*a&s takes +lace in the conte,t of a human acti!it& s&stem1 and +ro#lem

o*ners are +eo+le [16]- It is essential for requirements engineers to stud& ho*

+eo+le +ercei!e1 understand1 and e,+ress the +ro#lem domain1 ho* the& interact

*ith the desired +roduct1 and ho* the +h&sical and cultural en!ironments affect

their actions-

The con!ersational methods +ro!ide a direct contact channel #et*een engineers

and stakeholders1 and the requirements are mainl& no tacit- The o#ser!ational

methods +ro!ide an indirect channel #& o#ser!ing user.s interaction *ith his *ork

setting and conte,t1 and the requirements fall into tacit kno*ledge- The anal&tic

methods form one com+lementar& indirect contact channel to e,tract requirements

+roacti!el&- The s&nthetic methods focus more on collecti!e effort on clarif&ing the


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features of desired +roducts1 and the communication channel is therefore a mi, of

direct contact and indirect contact- Each t&+e of techniques has trade>offs- In

realit&1 of course1 the #oundar& #et*een different t&+es of method is #lurred-

Back to To+

%d&antage and Disad&antage o# 'e(uire$ent )*icitation

%fter the discussion the different of the four grou+ of requirement elicitation

method- In order to understand the each Requirement elicitation Methods and

effecti!e use them in the real case 1*e ha!e to focus on the ad!antages and

disad!antages of different requirement elicitation methods$ on!ersational1

"#ser!ational1 %nal&tic and '&nthetic one #& one-

/ %s con!ersation is a natural and effecti!e *a& of communication1 that.s *h& the

con!ersational methods are used massi!el&- on!ersational methods include

techniques such as$ inter!ie*s1


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requirements- E,+erts no*ledge and "+inion +la&s an im+ortant role in

requirement maturit&- Moreo!er1 reuse of alread& a!aila#le information sa!es

time and cost- %nal&tical methods ha!e hierarchical flo* of information as

*ell-

(isad!antages of %nal&tical Methods$ %long ad!antages1 %nal&tical methods

ha!e certain disad!antages as *ell- The #iggest disad!antage is that an

anal&tical method requires some em+irical data1 documentation or e,+ert.s

o+inions *ithout these it is difficult to elicit +ro+er requirements- 'imilarl&

anal&tical methods can narro* the !ision of +roduct- %s anal&tical methods

deal *ith some earlier kno*ledge so +ossi#ilit& of error re+lication is aserious and constant threat- %nal&tical methods are ne!er a good choice

*hen &ou are going to de!elo+ an altogether ne* s&stem- [/:]

Back to To+

Conc*usion

Requirements elicitation is a critical ste+ in the requirements de!elo+ment +rocess-

It is consequentl& im+erati!e that requirements engineers a++l& a++ro+riate

methods to +erform the +rocess sufficientl&- Based on *hich a +ractical guideline

for method selection is suggested1 *e ha!e attem+ted to +resent meaningful

insights into the feature of different t&+es of requirements elicitation techniques-

The classification of requirements elicitation methods is #ased on the nature of the

techniques- It re!eals the different communication channels for the anal&sts to elicit

requirements1 and +ro!ides the conte,tual situation for method selection-

It is *orth outlining that the techniques discussed in this +a+er are #ased on the

im+licit assum+tion that the human stakeholders and the requirements anal&sts are

coo+erati!e and sincere- The stakeholders are *illing to share kno*ledge *ith the

anal&sts and the anal&sts +re+ared carefull& #efore conducting an elicitation


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session- Requirements engineering is a com+le, social interaction +rocess1 the

techniques discussed in our +a+er +ro!ide anal&sts a +ro+er and conte,tual means

to +erform the +rocess- Besides1 the anal&sts should +ossess inter+ersonal skills to

hel+ #uild consensus #et*een heterogeneous grou+s of stakeholders- 'uch social

skills are as im+ortant as the techniques used in the engineering +rocess-


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'e#erence

/- Master thesis in com+uter

science htt+$***-ukessa&s-comessa&scom+uter>sciencemaster>thesis>

in>com+uter>science-+h+

:- Requirements =athering and (etermination

htt+$#aggins-nottingham-edu-m&Gsdaniel=H:C''Cecture

:4)otesRequirements:4=athering-+df

3- Bashar )usei#eh1 'te!e Easter#rook Requirements Engineering$ %

Roadma+ htt+$***-doc-ic-ac-ukG#an+u#ssotar-re-+df

;- B&rd1 T-%-1 ossick1 -C- and Jmud1 R-6- % '&nthesis of Research on

Requirements %nal&sis and no*ledge %cquisition Techniques- MI'

online-org?roceedings:44:'+kr?(F'ThrTracs+2/-+df1

'oft*are Technolog& 'u++ortenter A'T'

K- =um+1 F-1 :4421 Requirement Elicitation Techniques

htt+$***-docstoc-comdocs/K43K;KKRequirements>Elicitation>

Techniques(ocument>I(>'6E)=>(I

0- 9a*le&1 M-1 :4421 Caddering$ % Research Inter!ie* Technique for

7nco!ering ore @alues

htt+$***-u,matters-commtarchi!es:4424Kladdering>a>research>

inter!ie*>technique>for>unco!ering>core>!alues-+h+-

2- 9olt8#latt1 - and Be&er1 9- Making customer>centered design *ork for

teams- omm- %M1 3 A/4- 23 L /43


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/4- 9udlicka1 E-1 Requirements elicitation *ith indirect kno*ledge elicitation

techniques$ com+arison of three methods- in Requirements Engineering1

Aolorado '+rings1 "1 /221 ; L //

//- Ceffing*ell1 (- and 6idrig1 (- Managing 'oft*are Requirements > % 7ser

ase %++roach1 :nd Ed- %ddison>6esle&1 :443-

/:- Clo&d1 6-D-1 Rosson1 M-B- and %rthur1 D-(-1 Effecti!eness of elicitation

techniques in distri#uted requirements engineering- in IEEE Doint International

onference on Requirements Engineering1 A:44:1 3// L 3/0

/3- Maiden1 )-%-M- and Rugg1 =- %RE$ 'electing Methods for Requirements

%cquisition- 'oft*are Engineering Dournal1 // A3- /03 L /2:

/;- )an )iu1 'te!e Easter#rook (isco!ering %s+ects in Requirements *ith

Re+ertor& =rid htt+$trese-cs-ut*ente-nl*orksho+searl&>as+ects>

I'E:44?a+ers:4)iu:4Easter#rook-+df

/H- )ielsen1 (-1 :442a1 Requirements =athering > hoosing the Right Tools

htt+$e8inearticles-comNRequirements>=athering>>>hoosing>the>Right>

ToolsidO:;32H/:- last checked :442>//>//]

/- )usei#eh1 B- and Easter#rook1 '-1 Requirements engineering$ a

roadma+- in ?roceedings of the onference on The Future of 'oft*are

Engineering1 ACimerick1 Ireland1 :4441 %M ?ress1 3H > ;-]

/K- Roel 6ieringa1 ?ractical Requirements Engineering 'olute

htt+$csdl-com+uter-orgcom+magsso:44;4:s:4/-+df

/0- Rottmann1 (-1 :4421 Doint %++lication (e!elo+ment

htt+$***-umsl-eduGsauter!anal&sis;00Pf4/P+a+ersrottman-htm-

/2-

'te+hen @iller 1Ian 'ommer!ille 'ocial anal&sis in the requirementsengineering +rocess$ from ethnogra+h& to method htt+$archi!e-cs-st>

andre*s-ac-uk'T'E 9and#ook?a+ers'ocial%nal&sisRE?rocess>@iller-+df

:4- 'u8anne Ro#ertson1 Dames Ro!ertsonions$ Mastering the requirements

+rocess/220


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:/- 6ai>hing CeungQ ho* to design questionnaire- 7ni!ersit& of East %nglia

htt+$student-#m5-com#ackPissues44/education/0K-html

::- Jhang1 J-1 :44K1 Effecti!e Requirements (e!elo+ment > % om+arison of

Requirements Elicitation techniques1 Tam+ere1 Finland

requirement elicitation techniques.doc

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