11.15 Some Functional Design Considerations

The speed of an application is a simple function of its complexity and how many other jobs are concurrently executing in the system.

Unrealistic expectations of hardware performance may be a problem. Insufficient CPU/DASD power cannot possibly support the application complexity and number of users.

Quality and speed have a price. If you want these, then you must be prepared to pay a reasonable price.

Remember KISS - Keep it Short and Simple. Avoid "over-development" by resisting the urge to give users 150% of what they want, presented to them in a fashion that is 200% better than before.

These types of solutions impress end users, but usually add to the size and the complexity of the application (which increases its maintenance cost) and the amount of resource it consumes (which may mean that you need a more powerful computer to run it).

If you progressively alter your original STANDARD intention into a SUPER solution, you must make sure that you can afford the "running costs" before you implement it.

This may be a problem when using 4GL tools.

Since 4GL tools are fast at designing and developing applications, they allow you to develop a SUPER application at the same cost, and in the same time frame, as you formerly produced a STANDARD application.

However, you must make sure MIS staff and machines are capable of running and maintaining the SUPER solution.

4GL tool users generally fall into 2 categories:

Both users gain significant benefits for their organizations, but the second type of users need to understand that the increase in the complexity and functionality may require more resources to run and maintain their applications.