Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Functional vs Non-functional Requirements - Which comes first?


Published on

What is the actual value of non functional requirements? How to identify them? What is the best practice of managing NFR?

Published in: Leadership & Management
  • Hello! Get Your Professional Job-Winning Resume Here - Check our website!
    Are you sure you want to  Yes  No
    Your message goes here

Functional vs Non-functional Requirements - Which comes first?

  1. 1. Chicken or egg? Which comes first: functional or non-functional requirements
  2. 2. About 10+ years in IT 8+ years on a management position 6+ years of Agile experience
  3. 3. Non-functional requirement is a requirement that specifies criteria that can be used to judge the operation of a system, rather than specific behaviors
  4. 4. FR vs NFR Functional Requirements Non-Functional Requirements Product Features Product Properties Describe the actions of user Describe the experience of user. How easy to use? How quick it executes? Functions that can be captured in use cases Global constraints that result development and operational cost Can be traced as individual module of program Is a basement of program module
  5. 5. Lets go Deep into Details
  6. 6. What is the source of requirements?
  7. 7. Company’s Strategic Goals are the Source of Requirements
  8. 8. Business User System Sponsor Point of View Scope of the Project Business Objectives User’s Point of View (UI) User Goals Functional Requirements What the system does Non-Functional Requirements Who well System does it Epic/Feature User Story Acceptance Criteria
  9. 9. Type of NFRs Important to User Important to Team Important to business Performance Maintainability Time to market Security Portability Cost Usability Reusability Flexibility Compatibility Testability Speed Accessibility Naming Convention Flexibility Tech Stack Disaster Recovery Monitoring
  10. 10. NFR Identification Interviews Brainstorm Prototyping Workshops Questionnaire End-User Requirements SLA, SLO
  11. 11. Example
  12. 12. SSL, 2048 bit encryption, Key stored at Key Vault, 1000 ops/sec Caching of processed files on HDD Retrieve Document Pages Page-by-Page Navigation
  13. 13. Enabler & Feature
  14. 14. NFR Evaluation Identify Quality Factors Define Measurable Criteria Define Acceptance Criteria NFR List of Enablers
  15. 15. Context>Attribute>Metric System Context Attribute Metric Should Value Must Value Add new Item (Context) Fast enough (Shall Be) # of ms to finish Should <500ms Must <1000ms
  16. 16. Impact Pros & Cons Analysis
  17. 17. Some Examples of NFR 99,9% uptime No downtime deployment Usage of Specific Provider Response time Browsers & Platforms App should be deployed at 3 different AWS Zones
  18. 18. Build your system Non functional Requirements Functional Requirements User Facing Functionality & UI Business Goal That leads to…
  19. 19. Thank you!
  20. 20. Lets be in touch! IN: Mail: FB: Medium: