Goal-Scenario Based Anaylsis

Goal-Scenario Based Analysis

• An analysis using goal and scenario models to express and refine requirements
  Provides rationale for the requirements
  Supports requirements analysis through scenarios
  Refines goals through scenarios

 

Goal-Scenario Modeling

• Inputs : Initial requirements
  Outputs : Goal tree
  - Abstraction levels provide separation of concern and levels of goal & scenario modeling
• The 4 abstraction levels
  - Business : represents the ultimate purpose of a system
  - Service : represents the services that a system should provide to an organization and the rationale
  - Interaction : represnents the interaction between system and external agent
  - Internal : represents what the system needs to perform the interactions selected at the user level

 

Requirements Prioritization

• Need to select what to implement, after analyzing requirements
  Customers usually ask for too much
  Balance time-to-market with amount of functionality
  Decide which features go into the next release
• For each requirement/feature, ask:
  How important is this to the customer?
  How much will it cost to implement?
  How risky will it be to attempte to build it?
• Perform Triage

 

Analytic Hierarchy Process(AHP)

• Create n x n matrix for n requirements
• Estimate the eigenvalues