This phase of work is based on the requirements of the requirements specification, design, architecture, build the appropriate software systems and interfaces relations break down the entire system into a number of sub-systems or modules, defined subsystems or modules, specific to each subsystem design definition, writing software outline design and detailed design specifications, database or data structure design specifications, assembly and testing program. In the initial stage of any software or system development must fully grasp the user needs to be able to follow the system development process which functions should be implemented, in what size and what limits to set the priority to be positioned. Systems engineers will thus complete the final design of computer software maintenance, on this basis for the subsequent program development, system functionality and performance and limitations described in a definition. Maintenance refers to the development of the software has been completed (analysis, design, coding and testing) work and deliver future use software maintenance type, some software engineering activities carried out by the software product. That is according to the situation of software running on the software appropriately modified to meet the new requirements, and correct errors found run. Writing software problem reports, software modifications report. A medium-sized software software maintenance services, the development stage if it takes time for one to two years, it is put into use in the future, its operating or working time may last five to ten years. Then its maintenance stage also running during this five to ten years. Maintenance System Software | Chaoyang software maintenance | Shenyang Fung and provided by the Shenyang City HSBC and Information Technology Center. Shenyang City HSBC and Information Technology Center (www.4000010001.com) (www.tz1288.com) strong, credible, in Shenyang, Liaoning province IT project cooperation industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead abundance and information technology center and you hand in hand into the brilliant, for a better future!