• NK 20_21, HK20_21, HK21_22

Stakeholders

Stakeholder is a person or organisation that (in)directly influences the requirements of a system.

• Users of the system
• Operator of the system
• Purchaser / Sponsor / Controller
• Software Developer
• Software Architects
• Tester

Classification

• Kind: which class of requirement do we have
  • Functional: Functionas, Behavior
  • Quality: Performance, Usability, Security, Availability, Portability, Maintability
  • Constraint: Physical, Legal, Cultural, Environmental
• Representation: How is it written down?
  • Operational: can be specified with pseudocode. Review, test, or formal verification. “System shall compute the sum of all numbers”. A process verb or action verb is used
  • Quantative: can be verified with measurement. “95% der Anfragen werden in 200ms bearbeitet”
  • Qualitative: can be specified with goals. Only subjective verification, can not be verified by review. “System has a good usability”
  • Declarative: description of a required feature. Like qualitative, but can be verified by review. “Any unauthorized access to the customer data shall be prevented”
• Satisfaction: When is requirement fulfilled?
  • Hard: If requirement is not fulfilled, system is not usable
  • Soft: If requirement is not fulfilled, system can degrade, but be usable

Function vs Quality vs Constraint

Quality:

Constraint: Define the Non-Functional aspects of a system or component, such as restrictions on technology, resources or techniques to be used.