Fuzzy Optimization Models for Quality and Cost of Software Systems Based on COTS

Abstract With the rapid increasing of the complexity, size and cost of software systems, the use of existing COTS (Commercial Off-The-Shelf) products has been playing a more and more important role in developing a high quality software system to satisfy both the user requirements and the developer budget. So selecting the best COTS software products has become the key to the quality and cost of software systems based on COTS. This paper presents a fuzzy optimization model for selecting the best COTS software product. The objective function of the model is to maximize quality within a fuzzy budgetary constraint. The software system consists of several programs, where a specific function of each program can call upon a series of modules. Several alternative COTS products are available for each module. A weight to the modules is given by utilizing the Analytic Hierarchy Process (AHP) based on the access frequencies of the modules. A simplified example is given to demonstrate each optimization model, and the results show that the proposed model is correct, feasible and valid