Software development as a process of improving the software quality. It is a manage process that is based on application of the whole or part of the development process models in many cases. All the processes that take place during the development of software are integrally important and if they are not followed correctly then they all can lead to failure, IT project to fail or hinder further development. The key steps in software development include problem identification, research, solution requirements, preliminary design, detailed design, coding, testing and maintenance. A wide range of failure occurs due to the lack of knowledge or poor understanding of software process model principles. Failure can occur at any stage and consequences can have a huge impact on time and budget costs. This can be prevented if there is full awareness about the specifics of any software process model principles that are being used. The following article discusses some commonly used software development methodologies.