Logical cohesion is one of the levels of cohesion in software engineering that describes how closely related the tasks or operations within a module or component are based on some logical relationship, but this relationship may not always be obvious or meaningful. In modules with logical cohesion, elements are grouped together because they perform operations on the same data structures or share some common characteristic, even though their purposes may not be strongly related. Here are key characteristics and considerations related to logical cohesion:
Common Theme: Elements within a module with logical cohesion share a common theme or feature, but this theme might not represent a clear, functional purpose.
Limited Logical Relationship: The logical relationship between elements may not be as strong or well-defined as in other cohesion types. Elements are often grouped together because of some superficial connection.
Limited Independence: Tasks within a module with logical cohesion can have limited independence, meaning that changes to one task may impact others, but the relationship is not as clear as in other cohesion types.
Documentation Challenges: Modules with logical cohesion may require more comprehensive documentation to explain the logical relationship between elements and why they are grouped together.
Potential Confusion: Logical cohesion can sometimes lead to confusion among developers who may not immediately understand the rationale for grouping certain elements together.
Examples: Examples of modules with logical cohesion might include a module that processes various types of data records without a strong functional theme, or a module that contains a collection of utility functions related to different aspects of the system.
Situational Applicability: Logical cohesion may be suitable in situations where a module needs to manage various aspects or characteristics of a system without a clear, single-purpose function.
Balancing Cohesion and Coupling: When designing software, it's important to balance cohesion and coupling. While logical cohesion may be appropriate for certain tasks, it's generally desirable to aim for higher levels of cohesion, such as functional cohesion, within modules to promote modularity and maintainability.
In summary, logical cohesion is a level of cohesion in software engineering that describes modules where tasks or elements are grouped together based on some logical relationship or common theme, even though the relationship may not represent a clear, functional purpose. While it can be suitable in certain situations, it may require additional documentation and can potentially be less intuitive compared to modules with higher cohesion levels. Careful consideration should be given to the appropriateness of logical cohesion for a given module or component.
