Software projects generally have to deal with producing and managing large and complex software products. As the functionality of computer operations become more essential and yet more critical, there is a great need for the development of modular software system. Component-Based Software Engineering concerned with composing, selecting and designing components to satisfy a set of requirements while minimizing cost and maximizing reliability of the software system. This paper discusses the fuzzy approach for component selection using "Build-or-Buy" strategy in designing a software structure. We introduce a framework that helps developers to decide whether to buy or build components. In case a commercial off-the-shelf (COTS) component is selected then different versions are available for each alternative of a module and only one version will be selected. If a component is an in-house built component, then the alternative of a module is selected. Numerical illustrations are provided to demonstrate the model developed.