Attribute Driven Design

Intro

• ADD takes as input a set of QA scenarios and uses knowledge about relation between quality attribute achievement and architecture in order to design the architecture.
• ADD is an approach to defining a software architecture that bases the decomposition process on the quality attributes that the software has to fulfill.
• Recursive decomposition process where at each stage, tactics and architectural patterns are chosen.
• ADD is started after requirements analysis - where the QA drivers are thought to be well understood.
• Output of ADD is first levels of module decomposition.
• System is described as a set of containers for functionality and interactions between them.

Input to ADD

• Functional requirements - typically expressed as use cases.
• Quality requirements - must be expressed as system specific quality scenarios.
• Design constraints.

ADD Steps

1. Choose module to decompose - Usually starts with the whole system.
2. Refine Module

• • Choose architectural drivers
  • Choose a pattern/style that satisfies these drivers.
  • Instantiate modules and allocate functionality to them from the use cases.
  • Define interfaces of child modules. Decomposition provides modules and constraints on module interactions - document this info in the interface document for each module.
  • Verify and refine use cases and quality scenarios and make them constraints for child modules.

1. Repeat steps for every module that needs decomposition.