on requirements completeness analysismethod viktoria gingina institute for system programming, ras 1...
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On requirements On requirements completenesscompleteness
analysisanalysismethodmethod
Viktoria Gingina
Institute for System Programming, RAS
1
Scientific AdviserAlexander K. Petrenko, Doctor of Science
Requirements are:
A condition or capability that must be met or possessed by a system or system component to satisfy a contract, standard, specification, or other formally imposed documents.
A condition or capability needed by a user to solve a problem or achieve an objective.
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A documented representation of a condition or capability as in (1) or (2).
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(1)
(2)
(3)
IEEE Standard Glossary of Software Engineering Terminology
Requirements in software development
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Bad requirements results:
Rising of errors numberHigh project risks level
Rising of modifications number
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Low interoperability
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Long time of developing and testing
Low-quality product
Broken date of performance
Increased cost
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Criteria of well-stated requirements
Completeness
Unambiguity
Adequacy
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Consistency
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requirements meet customer wishes
different domain experts understand requirements equally
requirements are coordinated and do not contradict one another
any situation has its own description in the requirements
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What do complete requirements mean?
Describes everything customer wants
Describes all logically possible situations
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Reasons of requirements incompleteness
-“System behavior is undefined in this case” premeditated incompleteness
- “System behavior is obvious, usual and do not need any additional explanation”
- Insufficient analysis of requirements
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- “System behavior is undefined in this case” impartial non-determinism
and so on7
- Requirements correction
To find incompleteness symptoms
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Test-cases, test-planes, test-reports
Specifications
Static and dynamic analysis of implementations
To find incompleteness symptoms
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Specifications
Static and dynamic analysis of implementations How to find
incompleteness symptoms
- Check-lists
- Patterns
- Anti-patterns
Test-cases, test-planes, test-reports
Examples of anti-patterns
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There is a condition-element but not all flow-branches are described.
Changing the data is described in one action branch but there is no any description for the same data in the other branch.
A new function, type, object, term is used but never described.
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yes
Instructions for “no”
no
Not all flow-branches are described (1)
then
Instructions for “else”
else (otherwise)
if?
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success
Instructions for error
errorres error
Instructions for success
successres
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Not all flow-branches are described (2)
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s: A,B,C,D.
s=A
s=D
s=B
s=C
r: real r>0
r=0
r<0
Examples of anti-patterns
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There is a condition-element but not all flow-branches are described.
Changing the data is described in one action branch but there is no any description for the same data in the other branch.
A new function, type, object, term is used but never described.
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No data element description in other branch
A=...
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Instructions for B
B=...
C=...
C=...
A=...
Data element - parameter,
object pointer,
and so on...
file content,
picture,
Examples of anti-patterns
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There is a condition-element but not all flow-branches are described.
Changing the data is described in one action branch but there is no any description for the same data in the other branch.
A new function, type, object, term is used but never described.
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Element is used but not described
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А – is …
B works like A but..
D works like С but..
Where is С description?
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Plan of future work
Define incompletenesssymptoms
Formalize process of requirements developing and recording
Define techniques to find incompleteness symptoms
Automate incompleteness detection
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