Program execution based module cohesion measurement

Module cohesion describes the degree to which different actions performed by a module contribute towards a unified function. High module cohesion is a desirable property of a program. The program modifications during successive maintenance interventions can have negative effect on the structure of the program resulting in less cohesive modules. Therefore, metrics that measure module cohesion are important for software restructuring during maintenance. The existing static slice based module cohesion metrics significantly overestimate cohesion due to the limitations of static slicing. In this paper, we present a novel program execution based approach to measure module cohesion of legacy software. We define cohesion metrics based on definition-use pairs in the dynamic slices of the outputs. Our approach significantly improves the accuracy of cohesion measurement. We implemented our technique and measured module cohesion for several programs. Cohesion measurements using our technique were found to be more insightful than static slice based measurements.