Structured systems analysis and design method

Structured Design (SD) is a design pattern in software engineering by Edward Yourdon and Larry Constantine, which supports modular design to describe in addition to the purely functional hierarchy, the interactions of higher-level modules. SD is used with the Structured Analysis (SA) in software engineering.

Approach

The Structured design bridges the gap between the technology-neutral analysis and the actual implementation. In structured design technical constraints are introduced and defined the basic structure of the system from a technical perspective. It thus provides the conceptual planning of the implementation dar.

The methodology provides means of structure diagrams functional modules hierarchically and shows by the single invocation hierarchies among modules. A functional module consists of one or more functional abstractions. This, in turn, represents one of the first abstraction mechanisms and grouped multiple related program commands to units ( functions). An example would be to calculate the square root of sqrt (x). The user does not need to know details about the implementation, but applies the function only. For this he needs an appropriate interface description, which belongs as creating the module hierarchy as the Structured design. A Functional module has no internal memory, which means it does not contain data ( private data ), which are only visible in the module. It can only store data in global information ( for example, when calculating a random number ). Later that build methods, such as the modular design (MD), introduce abstract data types and data objects.

Use

Object-oriented analysis and design have repressed structured methods in many areas. For banks, insurance companies and in the embedded space still find many system developments with structured methods instead. Especially in the field of mobile business computer systems are often used, which have limited resources for an object-oriented implementation with their overhead is too expensive. Further, the integration of existing applications in the context of EAI are often implemented as part of the subsystems that can not be implemented with object-oriented languages ​​. Therefore, would object-oriented analysis and design, who otherwise found the world very wide spread, constitute false implementation arrangements.

Function-oriented method

Tasks are top-down decomposed into subtasks and then these mapped to the modules ( modularisation ).

Description funds are structural diagrams in which the modules and the connections between modules are presented.

Example

Menu customer management is divided into Customers form and report customer.

• Software Engineering
• Systems Engineering