Structured analysis and design technique

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

Introduction

SADT, which is a trademarked and copyrighted by Softtech Inc in 1976. A SADT model is a collection of diagrams organised in a tree structure. Consists on watch for the software requeriments and the design of systems/software using a group of processes that lets the analist to view the functions. Also uses a graphic notation, activity models and data models, that communicates the relations between information and functions.

SADT activity models were used to define IDEF0.

Philosophy

Diagrams are build using the techniques that are below. The objectives for this diagrams is to show the flow of information between the organization and the activities that the organization do. Using SADT, the analist develops a model with a lot of graphic datagrams and activity models.

Stages

This automatic tools bring support for the process of analisys and an organizative method well organized by using them. Thus revisions and points of reference allow to make a validation of the comunication between customer and developer.

Techniques

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

The Semantics of Arrows

For activities:

Inputs are data that are consumed by the activity

Outputs are produced by the activity

Controls influence the execution of an activity but are not consumed

For data:

Inputs are activities that produce the data

Outputs consume the data

Controls influence the internal state of the data