Software development process model plays a key role in developing high quality software. However there is no fit-for-all type of process model exist in software industry. To accommodate some specific project’s needs, process models have to be tailored. Extreme Programming (XP) is a well-known agile model. Due to its simplicity, best practices and disciplined approach researchers tried to mold it for various types of projects and situations. As a result a large number of customized versions of XP are available now days. The aim of this paper is to analyze the latest customizations of XP. For this purpose a systematic literature review is conducted on studies published during 2013 to 2017. This detailed review identifies the objectives of customizations, specific areas in which customizations are done and practices & phases which are being targeted for customizations. This work will not only serve the best for scholars to find the current XP states but will also help researchers to predict the future directions of software development with XP.

Feature driven development (FDD) is a process oriented and client centric agile software development model which develops a software according to client valued features. Like other agile models it also has adaptive and incremental nature to implement required functionality in short iterations. FDD mainly focus on designing and building aspects of software development with more emphasis on quality. However less responsiveness to changing requirements, reliance on experienced staff and less appropriateness for small scale projects are the main problems. To overcome these problems a Simplified Feature Driven Development (SFDD) model is proposed in this paper. In SFDD we have modified the phases of classical FDD for small to medium scale projects that can handle changing requirements with small teams in efficient and effective manner.

Extreme programming is one of the widely used agile models in the software industry. It can handle unclear and changing requirements with the good level of customer satisfaction. However Lack of documentation, poor architectural structure and less focus on design are its major drawbacks that affects its performance. Due to these problems it cannot be used for all kinds of projects. It is considered suitable for small and low risk projects. It also has some controversial practices that cannot be applied in each and every situation like pair programming and on-site customer. To overcome these limitations a modified version of XP called “Simplified Extreme Programming” is proposed in this paper. This model provides solution of these problems without affecting simplicity and agility of extreme programming.