Objectives of Design

Design activities are aimed at designing and confirming the external aspects of the system with end user representatives.

You must ensure that the external design of the system is suitable for the proposed business users, locations, and broadly suitable in technology for the expected volume and speed of response. Detailed technical issues are usually deferred until the users agree with the functionality of the design, its form, and its suitability to meet the business objectives for developing the system.

For example, an analyst may have discovered that the business needs to keep track of customers. The analyst may have defined an elementary process, called Add Customer, in which the rules for adding a new customer are specified to support this requirement.

You must consider the following questions during design:

Should customers be added online, in batch, or both?
If online, should a user be allowed to add multiple customers in a single execution?
How should the user interface (screen or window) look, and how should the user interact with it?
Should the process Add Customer be combined with other elementary processes, such as Change Customer and Delete Customer, into a single procedure?
Should a client/server environment be used, and if so, which system components should be implemented in a client or server role?

Other objectives of design (constraints on the form of the system) include ensuring that the development of the new system, where possible, exploits and protect investment in other systems. This requirement may involve designing procedures to make the best use of current (sometimes called legacy) systems and data. It may also be necessary to design the system to work with some other system that is currently planned or under parallel development.