Objectives of Design

Your goals for design activities are designing and confirming the external aspects of the system with end user representatives.

You, the designer, must ensure that the external design of the system is suitable for the proposed business users and locations and broadly suitable in technology for the expected volume and speed of response. You will probably want to defer consideration of detailed technical issues until the users agree on 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 must keep track of customers. You may have defined an elementary process, called Add Customer, in which the rules for adding a new customer are specified to support this requirement.

To implement the process during design, you must address issues such as shown next:

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?

There may be other objectives of design or constraints on the form of the system. For example, management may want the new system to exploit and protect investment in other systems wherever possible. This may involve designing procedures to make effective use of current systems and data. You may hear the term legacy applied to current applications and data storage structures that will survive into the new system. Management may also want you to design the new system to work with some other system that is currently planned or under parallel development.