In earlier days of computing, researchers in the United Kingdom developed the Structured System Analysis and Design Method (SSADM). In the late 1970s, the U.K. Governments Central Computer and Telecommunications Agency was concerned about designing information systems in the future. SSADM gave the government a rigid methodology by which they could, theoretically, approach the design of various
. information technology systems, including payroll, human resources and inventory. This approach naturally provides a number of advantages and disadvantages. Information system designed under SSADM cost more to develop. This is due to multiple factors, including a 7-stage waterfall project design, where the next stage cannot begin until the previous stage is satisfactorily completed. SSADM also requires a thorough data modeling stage, where the flow of information is visually mapped and analyzed by the receiving entity. Finally, the overall complexity of the processes requires the engaging entities to be trained in SSADM standards. The learning curve for this system is considerably high. In spite of these disadvantages, the ever-evolving SSADM (currently in its fourth version) ensures a solidly delivered information system. In the late seventies, a lack of such standards led to improperly designed systems, due in part to poorly communicated expectations and a lack of understanding of existing systems. SSADM ensure that both the contractor and the recipient of the system are clear about the project. Recipients are protected from a system that does not perform as expected, and contractors are protected from have to pick up the cost for accommodating endless criticisms of the systems performance. As a result, contractors and government entities are generally happy to use SSADM. The Central Communications and Telecommunications Agency, today known as the Office of Government Commerce, still maintains and enforces the SSADM standard. However, two separate offices facilitate its usage. First, the National Computer Center maintains the thorough documentation of the SSADM standard. Meanwhile, the Design and Authority Board is tasked with updating SSADM standards. http://www.smartdraw.com/resources/tutorials/ssadm-diagrams/ or http://www.comp.glam.ac.uk/pages/staff/tdhutchings/chapter4.html
