Structured Analysis and Design

This was the methodology of choice in the 1970’s and 1980’s. It made tremendous strides bringing software design and implementation forward from the original “seat-of-your-pants” style that many early programmers used. It brought a structure to the development and implementation of code, but it also brought along quite a bit of overhead. There are bits and pieces that have been incorporated into the Agile process, best epitomized by the SCRUM Methodology.

Structured Analysis and Design Edward Yourdon was developed by several people about the same time. One of the founders of this movement was Edward Yourdon, a great software engineer who unfortunately passed away on January 20, 2016. Technopedia has a short description of the Structured Analysis and Design, which is also called Structured System Analysis and Design Methodology (SSADM). The one thing it mentions is the use of the waterfall design, but this was never fully used at any of the places I worked. What is far more common is the phased or spiral life-cycle. These are where the implementation is done in phases where it is decided what parts are needed to create a workable system that can be used by others. For example, library or class  interfaces are created first with proper calls and reasonable return values. In a later cycle the libraries and classes are implemented in the order of importance. SSADM did provide quite a bit of overhead, but it also provided solid applications with few defects. Companies have strived to create a methodology that creates as high of quality of product without al the overhead of SSADM.