Improving Maintainability of COTS Based System Using Aspect Oriented Programming: An Empirical Evaluation

Commercial off the Shelf Software (COTS) based development leads to a faster time to delivery for the software systems. However, the maintenance of these systems tends to be more costly as components may have to be removed or replaced, and also these components may have recurring maintenance fees. The maintenance of a software component lies with the component developer and maintenance tends to be the most expensive phase of the software process. It is therefore ideal to have components which are easier to maintain. Also, the glue code that is used for bringing these components together should have fewer faults and be easy to maintain. In this paper, we studied the effects of AOP (Aspect-oriented programming) on the maintainability of two COTS based systems: Openbravo POS and Jasper reports. The effects were measured using the maintainability metrics of the ISO/IEC 9126 model. The results show that the AOP versions of the systems are more maintainable than the COTS-based OO versions of the systems. Specifically, the AOP versions are found to be loosely coupled, less complex and highly cohesive and the impact of change during maintenance low. However, we have also noticed that there are some implicit coupling introduced in the AOP versions that require further investigation.