1. Faculty of Engineering - Universitas Indonesia
Requirement Engineering
(part 1)
Prof. Dr.-Ing. Kalamullah Ramli
Electrical Engineering Department

2. Requirement Study
o Requirement are ubiquitous part of
our lives
o Understand the requirement through
communication
o Communication Problem?
• People are hard to understand!
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3. Human Nature
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4. Change is Constant
o What makes the change?
• Human nature
• Society
• Organization
• Competitors
o DESIGN: shooting at moving target!
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5. Why Requirement Study?
o Limitation of the designers
o Motivation
o Reduce the total cost
o How far shall we make the
requirement analysis?
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6. Failure of Requirement Analysis
o The penalty of getting Requirement
Engineering (RE) wrong is high
o Even the system did not fall, user is sub-
optimal and design costs are wasted
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7. Cases of Failure in RE
o How much library functions do you use?
o New software development (less than
30% in the market)
o How much mobile phone functions did
you use?
o .....
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8. Analysis Methods
o System analysis – top down
decomposition
o Establish goal/functions representation
in, e.g., data flow diagrams
o Quick and dirty methods
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9. Obstacles to RE
o Tacit knowledge
o Ambiguity
o Attitude and opinions
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10. Three Dimensions
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11. Four Worlds Framework
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12. User Requirements Framework
o User Context and Early Design
o Prototype and User Test
o User requirements documentation
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13. Users’ Limitation
o Users do not have clear vision of what
they want
o Goal can be fuzzy
o Do not know what is technical possibility
o But,once they get, they can see how it
can be improved .... or they simply do
not like it
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14. Requirement Types and Pathway
o High level functions, towards the final
goal
o Detail functions
o How functions should work
o Constraint on system operation
o Statement about performance
o Implementation constraints
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15. Requirement Types and Pathway
o Functional requirements
• The goals
o Non functional requirements (NFR)
• Quality
• Performance
• Environment issues
• Cost
• Time
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16. Constraints
o > are conditions or laws that the system
will have to obey during operation or
during design
• Human cognitive
• Physical
• Environmental
• Costs
• Legal
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17. User Requirements
Documentation
o General system characteristics
o Organizational structure
o Tasks scenario and interaction steps
o Technical environment
o System functions and features
o User interface design
o User support
o Physical environment
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18. User Requirements
Documentation
o Social and organizational
environment
o Standards and styleguides to apply
o Test plan
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19. Documentation
o Natural language?
o Technical language?
o Long, dense text?
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20. Documentation
o Structure standards (IEEE 830, Mazza et
al 1994)
• Natural language, but short and avoid
ambiguity
• Structured, defined items
• Management tools for diagram
• Categorize stakeholders and different
requirements
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21. User Context and Early Design
o Identify users and stakeholders, and
their characteristics
o Describe technical/physical/social and
organization environment
o Review: current process, similar systems
and products
o Perform expert review of design
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22. RE Tasks and Processes
o No “cook book”, but “roadmap”
o Dynamically: pre-design and within
design process
o Common methods:
• Interview
• Observation
• Questionnaires
• Text and document analysis
o Set Scope and Bainstoming
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23. User Requirement Methods
o Functionality Matrix
o Storyboarding
o Task analysis
o Task allocation
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24. Functionality Matrix
o This method is useful when the number
of possible function is high
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25. Goal Analysis
o Goal hierarchy and decomposition
• e.g. Final goal: Increase customers’
satisfaction
• Reduce processing time for constraint
• Improve personal service in ordering
• Reduce lead time for delivery
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26. Events Analysis
o Outcome is to scope the system in terms of
its input, output, and major functions
o Object oriented: focus on event
o Event process chains
• Where does the output from the process go to?
• What process or fuction is responsible for
responding to this even?
• Who or what is the destination of this even and
why do they want it?
• Input-Process-Output (IPO) charts
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27. Modeling
o Analysis + Modeling = elaborate
requirements
o Different methods
• Semantic model
• Conceptual model
• Process/information flows
• Data flow diagram
• Data structures
• Entity Relationship
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28. Faculty of Engineering - Universitas Indonesia
Requirement Engineering
(part 2)
Kalamullah Ramli
Electrical Engineering Department

29. Basic Objectives of RA
o To delineate the data requirements of the
enterprise in terms of basic data elements
o To describe the information about the data
elements, and the relationships among
them needed to model these data
requirements
o To determine the types of transactions
that are intended to be executed on the
database, and the interaction between the
transactions and the data elements
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30. Basic Objectives of RA
o To define any performance, integrity, security, or
administrative constraints that must be imposed
on the resulting database
o To specify any design and implementation
constraints, such as specific technologies,
hardware and software, programming languages,
policies, standards, or external interfaces
o To thoroughly document all of the proceeding in a
detailed requirement specification
o Data element can also be defined in a data dictionary
system, often provided as an integral part of the
database management system
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31. i* Family of Model
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32. Validation
o User’s understanding of the
requirement specification
o User agree that it accurately reflect
their wishes
o Different prototypes and scenario are
normally used
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33. Verification
o Requirement specification behaves
correctly and does not violate any of
the laws specified by the users
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34. Boundary
o The system built behaves correctly
(verification)
o The system output makes sens to the
user (validation)
o However, boundary can be blurred
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35. Balance the Requirements
o Different stakeholders have different
requirements
o Trade-off analysis methods, decision
making table, models, relationship maps,
etc
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36. Conduct Negotiation
o Structure options and choices
o Establish judgment criteria
o Explain the options
o Vote?
o Diagnose the cause of disagreement
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37. Conflicts
o Probably due to lack of shared understanding
• Handling personal attach – steering sensitive
topics away from them
• Blocking: challenge those who said: “it won’t
work ...”, “it can’t be done .... “
• Trade-off between NFR
• Test Assumptions
• Benefit Analysis
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38. Trade-off Between NFR
o Quality vs Delivery time
o Cost vs Development time
o Security vs Access
o Functional vs Usability,
Complexity Reliability, and
Maintainability
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39. Functional Allocation
o Automated or Manual
o Management Level
o Operational Level
o Some Guidelines
• Machine: repetitive processing, high
volume data processing, monitoring,
deterministic tasks
• Human: recognition, reasoning, flexible,
problem solving, non-deterministic tasks
and unpredicted events
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40. Initial Pathways and Scoping
for Requirements
o Policy-, or business-driven
o Problem-initiated
o Technical Driven
o External Environment
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41. Policy-, or Business-Driven
o Business, social-economical theories
o Williamson 1980 theory: predict the
type of organizational relationship
according to the goods that a customer
wants to acauire from a supplier
o Top-down decomposition
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42. Problem-initiated
o Existing system has problem
o Event-based analysis
• Event-tree analysis
• Failure mode-event analysis
• Cause-effect net
o Model-based analysis
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43. Technical-driven
o User’s immediate goals is often to
acquire new technology
o User’s work goal analysis
o Fit the new technology with existing
system
o Demon the functions of the new
technical
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44. Applications & Technology
Factors
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45. External Environment
o NFR
• Safety
• Security
• Accessibility
• Usability
o Market
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46. Conversation
o Rasmussen’s Framework (1986)
Communication is generally an
automatic and hence skilled process so
it is prone to slip- and lapse- error in
failure to listen and poor generation
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47. Conversation
o Discourse theory (Clark 1996)
• People communicate to establish and
achieve shared goals
• Motivated by purpose
• Cylce of exchanges
• Common ground of understanding
o Discourse: is the branch of linguistics
that investigates how meaning is
derived in context
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48. Conversation and Context
o Meaning is often constructed by the
context of conversation
• Role of speakers
• Place
• Time
o Shared belief
o Shared externally perceivable entities
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