Begin before master specifications, planning the overall design is very important, can reduce a lot of work, improve the efficiency and quality, even is the key to avoid project go to collapse, and after coding, there are a lot of work, such as testing, unit testing, system testing, integration testing, regression testing, test is in order to improve the quality of software, after consign is used, there are a lot of maintenance, maintenance is not only refers to fix bugs, upgrade is also one of the most important aspects of the maintenance function, and takes on maintenance cost is coding for several times,