Skip to content
Software Architecture Guide

Lightweight ATAM

Explanation

Section titled “Explanation”

A full ATAM review (see Architecture Tradeoff Analysis Method (ATAM)) uses moderated workshops. It takes anywhere from two days to several weeks. One source describes the typical SEI-specified evaluation as two to three days of facilitated workshops.

Lightweight variants, sometimes called mini-ATAM or ATAM-lite, compress the process into a single day. They are common in agile settings, where a formal two-day workshop is hard to schedule.

How the effort shrinks

Lightweight methods save effort in three ways:

  • Fewer people take part.
  • The analysis steps are simpler.
  • Results arrive faster.

The main cost drivers of ATAM are the number of stakeholders and the number of scenarios. A scenario is a short story about how the system should respond to a situation. Trimming either one cuts the cost.

What you still get

ATAM scenario analysis produces trade-offs, sensitivity points, and risks or non-risks. See ATAM Findings: Risks, Non-Risks, Sensitivity Points and Trade-off Points.

Who runs it

Lightweight reviews can be run by one or more external parties, by the team itself, or jointly. This suits intermediate reviews during a project.

Example

Section titled “Example”

A small team is halfway through building a booking system. They want a quick check of the design before the next phase. They pick a few important scenarios, such as “the system stays responsive during a sales peak”. They invite only the architect and a few key people. In one day they walk through the scenarios against the design. They leave with a short list of risks and trade-offs to follow up.

Trade-offs

Section titled “Trade-offs”

Speed comes at a price.

  • Less complete. Lightweight reviews do not claim to find all risks. They aim to find some of them in a short time.
  • Depends on people. The result relies heavily on the group’s understanding of the system, its context, and its creativity. Full ATAM is more rigorous in this respect.

Choose a lightweight review when speed and low effort matter more than full coverage.

Checks

Section titled “Checks”
  • The document states whether the architecture review was a full ATAM or a lightweight variant.
  • The document records who ran the lightweight review: external parties, the team, or both.
  • The document admits that a lightweight review may not have uncovered all risks.
  • The review results list trade-offs, sensitivity points, and risks or non-risks.
Section titled “Related”

Sources

Section titled “Sources”