Interactive Systems
Johan F. Hoorn
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Changing
Requested
System
Requirements
Johan F. Hoorn
Vrije Universiteit
Faculty of Sciences
Division of Mathematics and Computer Science
Department of Information Management and Software Engineering
[email protected]
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Contents
 Status
 Goal
 Case
 Theory
 Model of change
 Prospects
 Questions
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Status
 Sept. 1, 2001 – Sept. 1, 2005
 Supervisors: Hans van Vliet and
Gerrit van der Veer
 Three international publications
 Industries:

Human-Machine Interaction
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Goal
 Requirements management tool
- can we predict changes in what people want?
Integrate:
 Requirements engineering
 Task modeling
 Business modeling
 Emotion psychology
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Case
Events
New goals
New processes
Changing
system
requirements
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Theory
Figure 1. Inputs and outputs of the requirements engineering process.
How come
they disagree?
Task Model 1
Emotions
Task Model 2
Culture
Tool: Special
questionnaire
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Figure 2. The process model of DUTCH.
Cristina
TM1
TM2
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Figure 3. Van Welie task model in Groupware Task Analysis.
new goals
set new priorities,
arousing (new) emotions
new business
model
new
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Figure 4. Ontology of concepts in an ISAC activity model for current
or desired business situations.
new business
model
new
positive emotions
negative emotions
new
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Figure 5. The DUTCH process model with business model extensions.
GTA
ISAC
but where does
the change
come from?
requirements
specification
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Types of goals affecting requirements
Business goals:
- maximize profit
- make quality products
egotistic
altruistic
Personal goals:
- make a career
- support my company
egotistic
altruistic
New business model shifts focus
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Sources of conflict, regarding goals
Requirements change
Stakeholders
Client vs. Management vs. Employees
Business goals vs. Personal goals
egotistic
vs.
altruistic
egotistic
vs.
altruistic
Event
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Predictions for valence to business goals:
When new business goal supports
personal goals 
positive emotions, easy acceptance TM2, no
requirements change
When new business goal obstructs
personal goals 
negative emotions, difficult acceptance TM2,
requirements change
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Predictions for relevance of business goals:
When new business goal has personal
importance/real life consequences 
strong emotions, whether positive or negative
When new business goal has no
personal importance 
weak emotions, whether positive or negative
Relevance intensifies (non)acceptance TM2 and affects
the rank ordering of requirements (the priority list)
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Types of processes affecting requirements
Accurate processes:
- command from prompt
- task analysis
Inaccurate processes:
- JPEG decoder
- office assistants
fast
slow
Help
me!
fast
slow
New business model shifts focus
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Sources of conflict, regarding proceses
Requirements change
Stakeholders
Client vs. Management vs. Employees
Accurate process
vs.
Inaccurate process
fast
vs.
slow
fast
vs.
slow
Event
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Predictions for valence to business processes:
When new process is needed for goal
(whether business or personal) 
positive emotions, easy acceptance TM2, no
requirements change
When new process is undesired for goal
(whether business or personal) 
negative emotions, difficult acceptance TM2,
requirements change
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Predictions for relevance business processes:
When new process affects personal goals 
strong emotions, whether positive or negative
When new process is irrelevant to personal
goals 
weak emotions, whether positive or negative
Relevance intensifies (non)acceptance TM2 and affects
the rank ordering of requirements (the priority list)
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Model of change
change’
Agreed requirements
goal
egotistic
Maximize profit
Bring good
business
process
personal
Work way up
Employalty
Make chip
altruistic
fast
inaccurate
Empirical cycle
accurate
Relevance
Reflexes
Office assist
slow
Valence
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Figure 5. The DUTCH process model with business model extensions.
change’
Agreed requirements
goal
egotistic
Maximize profit
Bring good
business
personal
Work way up
altruistic
Relevance
Johan F. Hoorn
Employalty
process
Make chip
fast
inaccurate
Empirical cycle
accurate
Reflexes
Office assist
slow
Valence
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Prospects
 Ethnography (TM1)
 Structured questionnaires (TM2)
 Confirmative factor analysis
 Model fit
 Requirements management tool?
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Questions
 Let this not be one of them:
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