Software Engineering Institute | Carnegie Mellon University
Software Engineering Institute | Carnegie Mellon University

System Architecture Tradeoff Analysis Method

The purpose of the System Architecture Tradeoff Analysis Method (System ATAM) is to

  1. assess the consequences of architectural decisions in light of quality attribute requirements and business goals and
  2. discover risks created by architectural decisions in the system and software architectures of systems

Scenarios derived from quality-attribute-augmented mission threads, system use cases, architectural documents, and SoS architecture challenges (from the MTW) form the basis for evaluation in a System ATAM. The System ATAM is a variant of ATAM and addresses the following system areas:

  • System architecture notions and specifications - functional block diagrams, system control and data flow diagrams, electrical diagrams, mechanical drawings, DoDAF views, and so on
  • Engineering considerations – simulation studies, prototype development, and operator workload and stress studies
  • Quality attribute concerns – new quality attributes that serve as system architectural drivers (physical robustness, continuity of power supply source, and field-ability)
  • Architectural approaches – new architectural approaches may be needed to support additional engineering consideration required to create a system. (dynamic resource management, use of development common toolsets)
    Scope – additional considerations for a system (logistical, electrical , mechanical, weapons, sensor systems, .etc.)

 There are three phases to a System ATAM:

  1. Preparation Phase
    a. Determine if sufficient information and expertise (architectural
    documentation, relevant system architects,
    mission threads, system use cases) is available
    b. Develop scenarios for use during evaluation
    c. Identify stakeholders to participate
  2. Evaluation Phase
    a. Present business driver and architectural presentations and
    predefined scenarios
    b. Evaluate the scenarios
  3. Post-Evaluation Phase
    a. Evaluation team analyzes the information gathered and develops a set
    of architectural risk themes, which are vetted with system
    lead architects

The System ATAM is one of the methods used in the SoS Architecture Development and Analysis process.  It can be used independently of the SoS Architecture Evaluation and the Mission Thread Workshop or as a follow-on.


The System ATAM is ready to use. The SEI is currently looking for organizations that would like to incorporate the System ATAM as one of their routine software development practices. If you would like technical details about the System ATAM or if you would like to schedule one, contact us using the link in the For more information box at the bottom of this page.

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