Because of the quick growth of modular software development, the commercial-off-the-shelf (COTS) optimization selection model has become more well-known in software systems. In a software system, every module offers a range of options varying in characteristics such as quality, cost, size, execution time, and reliability. Considering these differences, selecting the appropriate COTS product can be difficult for software developers who use components. The selection process result will greatly affect the growth of COTS-based systems. Various optimization models have been proposed in the literature for selecting COTS products. Predicting the values of various model parameters accurately in the real issue of COTS products is difficult due to lack of data and errors in measurements. Hence, employing a flexible optimization model instead of a crisp optimization model could yield results more preferred by the decision maker (DM). This paper presents the use of GA variants for choosing the best COTS products for software development in a modular system. In this document, the DM needs to define different aspiration levels (ALs) based on their preferences and various shape parameters (SPs) in the exponential membership function (EMF) to show the effect of integrating solutions for effective allocation planning. A numerical example is given to demonstrate the effectiveness of GA variants in a real-world data set.