Goals and results to be achieved in each column stage of Software Development

Switch from external (Outline Design, detailed design ); Program Development, coding, unit testing, system testing, and system maintenance. In the software development process, it is necessary to clarify the work objectives of each stage, the work content necessary to achieve this goal, and the standards to be achieved. Only after the work in the previous stage is completed can the work in the next stage be started. 1. the feasibility study clarifies the purpose, functions, and requirements of the System, understands the current development environment and conditions, and demonstrates the following content: ① Is it supported by technical capabilities; ② economic benefits; ③ legal compliance; ④ consistent with the operation and development of departments and enterprises; ⑤ whether maintenance after the system is put into operation is guaranteed. The purpose of the Feasibility Discussion is to determine the value of software system development. The analysis and discussion contents form a "System Development Plan". The main contents include: (1) development purpose and expected results; (2) Basic Ideas of the system, business Objects and scopes involved; (3) development schedule, development organization structure; (4) development and operation costs; (5) expected system benefits; (6) problems that may occur during development and precautions. 2. System Requirement Analysis System Requirement analysis is the most important stage in Software System Development. It directly determines the development quality and success or failure of the system. It is necessary to clarify the user requirements and the characteristics of the application field environment, measure the test taker's knowledge about the functions, data flows, and data connections of the system. Demand analysis should be attended by users and conducted research and study at the site of use. software designers should consult technical and user personnel with an open mind to discuss methods to solve demand problems and analyze the survey results, clarify the problem. The Requirement Analysis content is compiled into a system requirement analysis report ". 3. The system design can be divided into two phases: Outline Design and detailed design based on the system scale. The outline design includes: ① dividing system modules; ② determining the functions of each module; ③ User Interface outline design; ④ Outline Design of input and output data; ⑤ report outline design; ⑥ data connection and Process Analysis; 7. Logical design of files and database tables; Identification of hardware and software development platforms; and standardization of regular data and data uniqueness requirements. The detailed design of the system further embodies the outline design of the system. Its main tasks include: ① physical design of files and databases; ② Design of input and output records; ③ detailed design of the processing methods and content of each subsystem; ④ programming task book. The statement of procedure usually includes the program specification, function description, and program structure diagram, which is usually described in the hpipo (hierarchy plus input process output) diagram. 4. Program Development uses computers according to the requirements of the program design task book Algorithm The steps for solving language problems include: ① understanding and further division of the module; ② logical design in the unit of module, that is, the preparation of the flowchart in the module; ③ writing Code Program is compiled using the programming language; ④ functional testing and unit testing in the module. Program quality requirements include: ① The exact functions that meet the requirements; ② High processing efficiency; ③ convenient operation and user-friendly interface; ④ the program code is readable, and the function and variable identification comply with the specifications; ⑤ good scalability and maintainability. Reducing Program Complexity is also very important. The complexity of the system is measured by the number of interfaces between modules. Generally, the maximum number of interfaces of N modules is n (n-1)/2, the minimum number of interfaces for N modules is n-1. In order to minimize the complexity, layers are often used for the module division design. Note that the program or module should be easy to understand and modify, and the module should be independent of each other. Modifications to a module should not affect the functions of other modules, there are as few links as possible between modules. 5. system testing is intended to detect errors in the program. It is inevitable that errors occur in the designed software. System Tests are usually conducted by experienced designers to design test plans and test samples, and to write detailed reports on the test process. System tests are carried out on the basis of unit tests, including: ① design of the test scheme; ② test; ③ write the test report; ④ the user evaluates the test result. 6. documents and documents include all Technical materials And the documents required by the user. Software System documents can be divided into system documents and user documents. User documents mainly describe system functions and usage without considering how these functions are implemented. system documents describe system design, implementation and testing. Documents are the deciding factors that affect Software maintainability and availability. In a word, every piece of paper of system programmers should be retained. Therefore, Document compilation is an important task in software development. System documents include: relevant documents for developing software systems in the planning, requirement analysis, design, preparation, debugging, and operation stages. During the modification of the software system, the system documents should be updated synchronously, And the modifier and modification date should be indicated. If necessary, the reasons for modification should be indicated, and outdated documents should be remembered as useless documents. User documentation includes: ① system function description; ② installation documentation, describes the system installation steps and system hardware configuration methods; ③ other meaningful reference: http://se.csai.cn/SoftDocuments/No085.htm