1. On requirements completeness analysismethod Viktoria Gingina Institute for System Programming, RAS 1 Scientific Adviser Alexander K. Petrenko, Doctor of Science

2. 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. 2 A documented representation of a condition or capability as in (1) or (2). 2 (1) (2) (3) IEEE Standard Glossary of Software Engineering Terminology

3. Requirements in software development 3 3

4. Bad requirements results: Rising of errors number High project risks level Rising of modifications number 4 Low interoperability 4 Long time of developing and testing Low-quality product Broken date of performance Increased cost ————————————————

5. Criteria of well-stated requirements Completeness Unambiguity Adequacy 5 Consistency 5 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 ————————

6. 6 What do complete requirements mean? Describes everything customer wants Describes all logically possible situations 6

7. 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 7 - “System behavior is undefined in this case” impartial non-determinism and so on 7 - Requirements correction

8. To find incompleteness symptoms 8 8 Test-cases, test-planes, test-reports Specifications Static and dynamic analysis of implementations

9. To find incompleteness symptoms 9 9 Specifications Static and dynamic analysis of implementations How to find incompleteness symptoms - Check-lists - Patterns - Anti-patterns Test-cases, test-planes, test-reports

10. Examples of anti-patterns 10 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.

11. 11 yes Instructions for “no” no Not all flow-branches are described (1) then Instructions for “else” else (otherwise) if? 11 success Instructions for error error reserror Instructions for success success res

12. 12 Not all flow-branches are described (2) 12 s:A, B, C, D. s=A s=D s=B s=C r: real r>0 r=0 r<0

13. Examples of anti-patterns 13 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.

14. 14 No data element description in other branch A=... 14 Instructions for B B=... C=... A=... Data element -parameter, object pointer, and so on... file content, picture,

15. Examples of anti-patterns 15 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.

16. 16 Element is used but not described 16 А – is … B works like A but.. D works like С but.. Where is С description?

17. 17 Plan of future work Define incompleteness symptoms Formalize process of requirements developing and recording Define techniques to find incompleteness symptoms Automate incompleteness detection 17

18. Thank you for your attention! Viktoria Gingina vgingina@ispras.ru