软件工程：Software Prototyping.pptVIP

Chapter 8 Software Prototyping Software Prototyping Rapid software development to validate requirements Objectives To describe the use of prototypes in different types of development project To discuss evolutionary and throw-away prototyping To introduce three rapid prototyping techniques - high-level language development, database programming and component reuse To explain the need for user interface prototyping Topics covered Prototyping in the software process Prototyping techniques User interface prototyping System prototyping Prototyping is the rapid development of a system In the past, the developed system was normally thought of as inferior in some way to the required system so further development was required Now, the boundary between prototyping and normal system development is blurred and many systems are developed using an evolutionary approach Uses of system prototypes The principal use is to help customers and developers understand the requirements for the system Requirements elicitation. Users can experiment with a prototype to see how the system supports their work Requirements validation. The prototype can reveal errors and omissions in the requirements Prototyping can be considered as a risk reduction activity which reduces requirements risks Prototyping benefits Misunderstandings between software users and developers are exposed Missing services may be detected and confusing services may be identified A working system is available early in the process The prototype may serve as a basis for deriving a system specification The system can support user training and system testing Prototyping process Prototyping benefits Improved system usability Closer match to the system needed Improved design quality Improved maintainability Reduced overall development effort Prototyping in the software process Evolutionary prototyping An approach to system development where an initial prototype is produced and refined through a number of stages to the final system T