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ALTERNATIVE SYSTEMS-BUILDING APPROACHES

1. Traditional Systems Lifecycle

The oldest method of building systems and is still used today for medium and large complex projects.

* It divides systems development into formal stages that must be completed sequentially with a very formal division of labour between end users and information systems specialists. Technical specialists are responsible for the systems analysis design and implementation work; end users are limited to providing information requirements and reviewing the technical staff’s work.

* It also emphasizes formal specifications and paperwork, so many documents are generated during the project.

Weaknesses

* Can be costly, time-consuming and inflexible. Although systems builders can go back and forth among stages in the systems lifecycle, usually tasks in one stage need to be completed before work for next stage begins. Activities can be repeated but volumes of documents must be generated and steps retraced if requirements and specifications need to be revised.

* Lifecycle approach is not suitable for many small desktop systems, which tend to be less structured and formalized.

2. Prototyping

This is the process of building an experimental system quickly and inexpensively for demonstration and evaluation so that users can get a better idea of their information requirements. The prototype that the users interact with is the preliminary working version of an information system for demonstration and evaluation purposes. Once operational, the prototype will be further refined until it conforms precisely to the users’ requirements.

Prototyping is iterative because the steps required to build the system can be repeated over and over again.

Steps in prototyping

i) Identify the user’s basic requirements.

Work with user to capture their information needs.

ii) Develop an initial prototype.

Designer CASE can use interactive multimedia....