SSADM can be thought to represent a pinnacle of the rigorous document-led approach to system design, and contrasts with more contemporary agile methods such as DSDM or Scrum.
[1] The principal stages of the development of Structured System Analysing And Design Method were:[2] The three most important techniques that are used in SSADM are as follows: The SSADM method involves the application of a sequence of analysis, documentation and design tasks concerned with the following.
A data flow Diagram is used to describe how the current system works and to visualize the known problems.
To answer these questions, the feasibility study is effectively a condensed version of a comprehensive systems analysis and design.
The requirements and usages are analyzed to some extent, some business options are drawn up and even some details of the technical implementation.
The developers of SSADM understood that in almost all cases there is some form of current system even if it is entirely composed of people and paper.
Through a combination of interviewing employees, circulating questionnaires, observations and existing documentation, the analyst comes to full understanding of the system as it is at the start of the project.
However, the considerations are quite different being: All of these aspects must also conform to any constraints imposed by the business such as available money and standardization of hardware and software.
Though the previous level specifies details of the implementation, the outputs of this stage are implementation-independent and concentrate on the requirements for the human computer interface.
Both of these use the events, function descriptions and effect correspondence diagrams produced in stage 3 to determine precisely how to update and read data in a consistent and secure way.
Keith Robinson, Graham Berrisford: Object-oriented SSADM, Prentice Hall International (UK), Hemel Hempstead, ISBN 0-13-309444-8