Föreläsning 5 - Modelling Functional Requirements

Question 1

Vilka är fördelarna med att modellera requirements?

Answer 1

• Models have been used for a long time with great success in many domains to specify systems and their properties, as well as for communication among modelling experts.
• Models for systems are based on modelling constructs. They:
  o Omit irrelevant details – reduce complexity, by abstraction mechanisms, such as selection, aggregation and classification.
  o Often focus on the presentation of a single perspective – data, functions, intensions, rules, etc.
  o May define additional properties – through selectable views, alternative model types, statistics and so on.
  o Checking/validating for completeness and correctness is less time-consuming than with NL because tools can be used.
  o Are easier to translate/map to program (or even executable) code than natural language. As such, they are an important bridge between the textual-based requirements and a future system.

Question 2

Vilka två sätt finns det att modellera på, och vad går de ut på?

Answer 2

Analyst driven

• Analyst analyses requirements sources and stakeholder requirements and creates models. Then consults with the stakeholders.
• Analyst creates models in a dialogue with stakeholder representatives.

Participatory modelling workshop (see Föreläsning 2)
- A group of stakeholders create a model together with the assistance of a modelling facilitator. In this case:
o The stakeholders are responsible for the knowledge that goes into the model.
o The facilitator is responsible for the modelling method used and the quality of the model.