Guru: Cohesion First – What A Procedure Should Be Responsible For

Cohesion is a fundamental principle in software design that dictates how closely related the responsibilities of a procedure should be. In the context of IBM i (AS/400) systems, understanding and implementing high cohesion within procedures enhances both performance and maintainability. A procedure must focus on a single task or closely related tasks, ensuring that its purpose is clear and its implementation straightforward.

• High cohesion leads to easier debugging and testing, as each procedure can be evaluated independently.
• It promotes code reuse, as procedures designed with specific responsibilities can be utilized across different applications.
• High cohesion simplifies the onboarding process for new developers, as they can quickly grasp the functionality of a well-defined procedure.

Conversely, low cohesion results in procedures that are difficult to understand and maintain. Such procedures often encompass multiple responsibilities, leading to increased complexity and a higher likelihood of errors. In IBM i environments, where legacy systems often coexist with modern applications, maintaining high cohesion becomes even more critical. Developers must prioritize the design of procedures that adhere to this principle, ensuring that each procedure encapsulates a single responsibility. This approach not only aligns with best practices in programming but also enhances the overall architecture of the system. By focusing on cohesion first, developers can create robust, efficient, and maintainable code that stands the test of time in the dynamic landscape of IBM i systems.