IBM i General Design Standards › Design Standards for Programs › Organizing Programs into Modules

Organizing Programs into Modules

Organizing the functions of your application system allows you to:

• insulate against change
• allow independent development and testing
• simplify the design
• make the system more robust

Modularization should serve to hide most of the internals of the module. The interface to each module should explicitly reference all the information required to use the module, and be the only way of invoking the module.

Modules should be chosen according to a number of criteria. Each module should be concerned with one fundamental task and should not carry out functions that are similar to or overlap with any other module—it should be ‘orthogonal’. Each module should have strong internal cohesion and weak coupling with other modules.