Software Engineering Discipline is constantly achieving momentum from past two decades. In last decade, remarkable progress has been observed. New process models that are introduced from time to time in order to keep pace with multidimensional demands of the industry. New software development paradigms are finding its place in industry such as Agile Software Development, Reuse based Development and Component based Development. But different software development models fail to satisfy many needs of software industry. As aim of all the process models is same, i.e., to get quality product, reduce time of development, productivity improvement and reduction in cost. Still, no single process model is complete in itself. Software industry is moving towards Agile Software Development.