Structured Systems Analysis & Design Method, SSADM, is a widely used computer application development method in the UK, where its use is often specified as a requirement for government computing projects. When launched in 1981, it was commissioned by the Central Computing and Telecommunications Agency, CCTA, in an attempt to standardise the many and varied IT projects being developed across government departments. Since then, SSADM has been even further refined and version 4 was launched in 1990. It is considered to be an open standard methodology that is freely available for use across the industry and one that many companies offer support and training for.
SSADM has a highly structured and even complex approach to the analysis and design phases of IT projects. Having been first adopted by UK government departments in the early 1980s, it soon proved popular within other organisations as its flexible and individually tailored methods came to light.
SSADM is very rich in techniques, providing ways to specify every element of a system from the database right through to business processes and the user interface. It can also be highly complex and therefore perform too slow for use on many projects, particularly where a rapid solution is needed. Having said that, SSADM was always intended to be flexible and tailored to the needs of individual projects.
2.Proposed Development Method
The SSADM methodology follows a standardised Waterfall Model approach to information systems development in the sense that it divides into stages the application development project into modules, steps and tasks and provides a framework for describing projects in a fashion suited to managing the project. This assures that each phase has to be completed and subsequently signed off before each phase begins. Due to its highly structured approach and complexity in its own right, it can be structured and tailored to the individual needs of a project. Like any other development method, SSADM has its core values that must be met for it to function properly. The fundamental principles are:
·The required system should be specified in detail and agreed with the users prior to development
·User involvement is crucial to identify and understand key requirements
·Development should be divided into separate stages
·Follow a 3-schema approach - Conceptual Model (the systems view), Internal Design (the physical database and programs) and External Design (the user view).
SSADM is based on the "waterfall" model and only covers the analysis and design phases in detail. It also highlights aspects of the life cycle of a system from the feasibility study stage to the production of a physical design and is generally used in conjunction with other leading methods such as PRINCE, which deals with the broader aspects of project management.
The Default Structural Model for SSADM is split into modules which are themselves divided into several stages:
3.Organisational Structure and Culture
3.1Feasibility Study: Stage 0
The initial stage sets out to assess the various technical, organisational, financial and business options available to the project. The goal being to establish whether the direction and requirements of the project are realistically feasible. In essence this is a shortened, higher-level version of Stages 1 and 2 (requirements analysis and requirements specification).
The aim is to evaluate the feasibility of the proposal, involving an analysis of the problem and determination of the best solution; usually ranges of potential solutions are presented. Data Flow Diagrams, Entity Relationship Databases, System Requirements and project management techniques along with extensive network diagrams are produced here.
One main issue that must be addressed are the costs expected for the system such as hardware and software expenses along with other 'expectations'...