In software engineering, Architecture Tradeoff Analysis Method (ATAM) is a risk-mitigation process used early in the software development life cycle.
ATAM was developed by the Software Engineering Institute at the Carnegie Mellon University. Its purpose is to help choose a suitable architecture for a software system by discovering trade-offs and sensitivity points.
ATAM is most beneficial when done early in the software development life-cycle when the cost of changing architectures is minimal.
The following are some of the benefits of the ATAM process: [1]
The ATAM process consists of gathering stakeholders together to analyze business drivers (system functionality, goals, constraints, desired non-functional properties) and from these drivers extract quality attributes that are used to create scenarios. These scenarios are then used in conjunction with architectural approaches and architectural decisions to create an analysis of trade-offs, sensitivity points, and risks (or non-risks). This analysis can be converted to risk themes and their impacts whereupon the process can be repeated. With every analysis cycle, the analysis process proceeds from the more general to the more specific, examining the questions that have been discovered in the previous cycle, until the architecture has been fine-tuned and the risk themes have been addressed.
ATAM formally consists of nine steps, outlined below: [2]
These steps are separated into two phases: Phase 1 consists of steps 1-6 and after this phase, the state and context of the project, the driving architectural requirements and the state of the architectural documentation are known. Phase 2 consists of steps 7-9 and finishes the evaluation [3]