structured analysis and design technique (SADT)
Structured Analysis and Design Technique (SADT) is a methodology for software development developed by Softech Inc, USA. This method aims to decompose and describe a system (problem) step by step and strictly hierarchically.
A distinction is made between functions and objects:
Functions: Activity analysis - the representation of which elements make up a functional process.
Objects: Data analysis - the representation of which components make up a thing, an object, a property, and how these components depend on each other.
Thus, each SADT model consists of a set of activities and a set of objects. Graphical elements and, of course, linguistic labels are used to represent them. The basic building block of SADT is a black box, whose boundary to the environment is defined by the inputs INPUT and CONTROL and by outputs OUTPUT and MECHANISMS acting on the element.
SADT contains precise agreements on how constraints and restrictions affect from one level of detail to subsequent levels, and how to account for them, ensuring that each level of detail is compatible with its parent level.
Elements are placed in a transformation relationship by means of directed edges (arrows) that go from the OUTPUT of one element to the INPUT or CONTROL input of another element. These directed edges are calledinterface.
The interface CONTROL (influence input) acts on a transformation(black box) in the sense of a restriction (influence). The interface MECHANISM specifies the tools that are available for the realization of the element. Related to an activity analysis, MECHANISM means a machine, computer, person, etc. that performs this activity. Related to a data analysis, on the other hand, MECHANISM is interpreted as a means of storing or representing data.