Non functional requirements
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The document discusses the importance of non-functional requirements in software development, highlighting aspects such as usability, reliability, performance, and security. It emphasizes identifying critical non-functional requirements to guide development choices and lists various categories like system, business, and general requirements. The document also includes guidelines for assessing and implementing these requirements effectively.
Non functional requirements
- 1. Non Functional Requirements 21.5.2010 - Pavel Růžička Product Development Department
- 2. Knowing of non-functional requirements Helps to avoid of customers say „Y o u s h o u l d t h in g b e t t e r !“ 2 21.5.2010 - Pavel Růžička Product Development Department
- 3. I t helps a lot if you know what is the “most critical“ non-functional requirement because this can dominate the best choice of development technique and internal design. 3 21.5.2010 - Pavel Růžička Product Development Department
- 4. 4 21.5.2010 - Pavel Růžička Product Development Department
- 5. Non-functional requirements are aspects • Users have implicit expectations about how well the software will work. • These characteristics include • how easy the software is to use, • how quickly it executes, • how reliable it is, • and how well it behaves when unexpected conditions arise. • The non-functional requirements define these aspects about the system. 5 21.5.2010 - Pavel Růžička Product Development Department
- 6. Non Fuctional Requirements - General • Security • Exception Handling • Validation • Logging • Tracing / Testing • Monitoring / Reliability • Transaction • Storage • GUI Binding • Configuration 6 21.5.2010 - Pavel Růžička Product Development Department
- 7. Non Fuctional Requirements– System / Dev • Naming conventions • Caching, Performance • Scalability • RAM usage • Thread Sync 7 21.5.2010 - Pavel Růžička Product Development Department
- 8. Non Fuctional Requirements - Business • Time to market • Cost • Speed / Performance • Interoperability • Flexibility • Disaster recovery • Usability • Accessibility 8 21.5.2010 - Pavel Růžička Product Development Department
- 9. How to fetch non-functional requirements? • A n t i- s t o r ie s are things the user does not want to happen, commonly for safety or security reasons. • N o way we let an I L OV E Y OU E M ail worm in our System! • U s e a c h e c k lis t 9 21.5.2010 - Pavel Růžička Product Development Department
- 10. Security - Should access to be limited? - Is an access list necessary? - Access Control List - White List - Black List 10 21.5.2010 - Pavel Růžička Product Development Department
- 11. Exception handling - What errors can occur on runtime? - What it should do in case of error? 11 21.5.2010 - Pavel Růžička Product Development Department
- 12. Validation • Which input items are required? • Which of them need to be validated? • What to do if input is invalid? • How to recognize if an item is valid? (email, personal number, ZIP code...) Be aware - customer tends to change it frequently! 12 21.5.2010 - Pavel Růžička Product Development Department
- 13. Logging • It is about loggin from the user perspective, not developer’s logging • Which events should be logged? • Which items should log contain? • Is the last operation enough or you need history? • How deep the history should be? • Where to log? (file/db/…) • Who should have access to logs? • Incremental or rotation log? • How to purge/delete logs? 13 21.5.2010 - Pavel Růžička Product Development Department
- 14. Tracing - testing • How to test an application? • Which parts of the application should traceable? 14 21.5.2010 - Pavel Růžička Product Development Department
- 15. Monitoring - SLA • How it will be monitored? • Are there any special monitoring rules? • Use cases will help you best: • How to watch each particular use case? • What to watch/track there? (user/action/result) 15 21.5.2010 - Pavel Růžička Product Development Department
- 16. Transaction • Which operation is „atomic“- what must be proceeded all at once? • How to do rollback/cancel an operation? 16 21.5.2010 - Pavel Růžička Product Development Department
- 17. Naming conventions Name of a product/service and internal naming (Windows Chicago vs. Windows 2000) • E s t a b lis h in t e r n a l n a m in g c o n v e n t io n s – it w ill h e lp y o u t o a v o id o f t r o u b le s • in c a s e o f u n c le a r p r o d u c t n a m e • in c a s e o f c h a n g e t h e p u b lic produc t na me 17 21.5.2010 - Pavel Růžička Product Development Department
- 18. Caching, performance • Think about scalability • What to cache • What must be strictly online • Prepare fallback scenario in case of outage 18 21.5.2010 - Pavel Růžička Product Development Department
- 19. Sources • http://en.wikipedia.org/wiki/Non-functional_requirement • http://broadcast.oreilly.com/2010/02/nonfunctional-requiremen • http://www.stellman-greene.com/2010/02/17/nonfunctional-req 19 21.5.2010 - Pavel Růžička Product Development Department