Change Requirements: An Explanation of What Stakeholders Try to Avoid

Change Requirements: An Explanation of What

Stakeholders Try to Avoid and What They Try to Achieve

Johan F. Hoorn, Elly A. Konijn,H. van Vliet, & G. vd Veer

Vrije Universiteit

Computer ScienceInformation Management and Software Engineering

[email protected]

Contents

Problem Analysis Model Method Case Results Conclusions

Johan F. Hoorn, 2005

M M I 9 9 0 0 9

Problem How can requirements change be anticipated?


Analysis Where do change requests come from?

Business model 1 Business model 2 Change in business sub goals - Main goals: Profit - Sub goals: Cost-effectiveness, efficiency

How come business goals change? Change in sub goals (strategic management) - Main goals: Earn my living - Sub goals: Fire employees (not me),

improve IT to guarantee same output


Model Change of Stakeholder Requirements (CoStaR) (Hoorn & Van der Veer, 2003a; 2003b)

One of the hypotheses:


Goals Valence Requirements

Stakeholder evaluation:Does a system feature support my goals?Does a system feature obstruct my goals?(after Frijda, 1986)

Method REquest, the Requirements Engineering questionnaire

General approach: Items that combine

- a must or a won’t requirement, with- support or obstruction of- a goal to achieve with the system or a goal state to avoid,

scored for agreement on a 6-point rating scale


Case Eighteen managers of a logistic warehouse management systemmust/won’t support/obstruct goal approach/avoid

E-mail ordering increases efficiencyE-mail ordering decreases efficiencyE-mail ordering increases inefficiencyE-mail ordering decreases inefficiencyPaper ordering forms increase efficiencyPaper ordering forms decrease efficiencyPaper ordering forms increase inefficiencyPaper ordering forms decrease inefficiency


Example items

Results (1) Original hypothesis:



- Indeed, goals, valence, and requirements all evoked significant effects on agreement to requirements statements

Results (2)


MANOVA (must vs won’t) * (support vs obstruct) * (goal approach vs avoid)Pillai’s Trace = .51, F(2,16)= 8.40, p= .003, ηp

2= .51

↑ Grand mean agreement

(.98)

(1.09)

(1.44)

(1.04)

(1.14)

(.96)2.192.41

1.8

2.78

3.67

2.5

0

1

2

3

4

5

Requirements(must have)

Requirements(won't have)

Valence(support)

Valence(obstruct)

Goals (toapproach)

Goals (toavoid)

Results (3) Original hypothesis:



- Bipolar conception does not hold Regression: R2= .03, R2

adj= -.03, F(1,16)= .47, p= .504

Goals(avoid)

Valence(obstruct)

Requirements(won’t have)

Goals(approach)

Valence(support)


- Goal-driven RE models should be unipolar

Results (4) However, original structure should be completely revised


Goals(to approach)


Valence(support)

Valence(obstruct)

Goals(to avoid)


Results (5)


R2= .93, R2adj= .90

F(5,12)= 30.30, p= .000

no predictive power

no predictive power

Requirements vs. goals: Parameter coefficient= -.56, t= -4.04, p= .001, ηp2= .49

Yet, valence does have influence. Valence is a moderator!

R2= .79, R2adj= .70

F(5,12)= 9.01, p= .001

90%!!



Valence(support)

Valence(support)

Goals(approach)

Goals(avoid)

70%!!

Conclusions (1)

RE should be oriented to goals Requirements validation should be done with structured questionnaires (e.g., REquest) Goals to achieve predict won’t requirements Goal states to avoid predict must requirems Like the weather, valence does not predict mood (i.e. agreement) but it does influence it


Conclusions (2) Most important RE questions are:

What are the things you want to achieve

with the system? What should the system NOT have to support that? What are the things you want to avoid with the system? What should be ON the system to support that?


Change Requirements: An Explanation of What Stakeholders Try to Avoid

Documents

Transcript of Change Requirements: An Explanation of What Stakeholders Try to Avoid