Investigating correlation between the object-oriented design maintainability and two sub-characteristics: Understandability and modifiability

Two sub-characteristics of Boehm's maintainability model are understandability and modifiability. The model does not clearly suggest which sub-characteristic has more influence on maintainability than the other. The goals of this work are to explore the relationship between the maintainability of object-oriented designs and its two sub-characteristics and to explore the structural complexity design metrics which can be indicators of maintainability. A controlled experiment is performed in order to achieve these goals. Combination technique called a weighted sum is applied for constructing the equation indicating the relationship. The experimental result reveals that modifiability has more influence on the maintainability than understandability.