Structured analysis and design technique

For the chemical reaction SADT, see Self Accelerating Decomposition Temperature

Structured Analysis and Design Technique — SADT is a Software Engineering technique for describing systems as a hierarchy of functions.

Techniques

SADT uses two types of diagrams: activity models and data models. It uses arrows to build these diagrams.

The Semantics of Arrows

For activities:

• Inputs enter from the left and represent data or consumables that are needed by the activity.
• Outputs exit from the right and represent data or products that are produced by the activity.
• Controls enter from the top and represent commands which influence the execution of an activity but are not consumed.
• Mechanisms identify the means, components or tools used to accomplish the activity. Represents allocation of activities.

For data:

• Inputs are activities that produce the data.
• Outputs consume the data.
• Controls influence the internal state of the data.

SADT is a method based in systems theory. Also see IDEF0.

SADT is available as a commercial CASE tool under the name IDEF0.

Links

• The IDEF0 method
• A course about SADT diagrams