Components

Routines and Modules

A routine is a generic program unit - a function, procedure, or main program
The quality of routines in a program have a tremendous impact on the reliability of that program.

A module is a collection of objects that are logically related. These may include constants, data types, variables, and program units. (routines)

Modularity and Abstraction

• Characteristic of all design methods.

• Components have clearly defined inputs and outputs, and clearly stated purpose.

• Easy to examine each component separately.

• Organized in a hierarchy so the system can be investigated one level at a time.

• Components at one level refine those in the level above.

• The more abstract top levels hide the details of lower level functional or data components