Design Patterns/Principles And Its Applications To Agent

Usually, it takes about half a year to develop a software system, but takes about many years to maintain it. During the lifecycle of a software project, the cost needed on the maintenance is two times as much as ones on the original development. So we should aware that it is a good software system only if new modules or modifications can be plugged into old system smoothly.Researchers are in the full conviction that a maintainable system has higher reusage rate. But in fact, as a coin has two sides, maintainability and reusability are independent aims of software design. Therefore, for the object-oriented software system, it is the most important issue to enhance the reusability of the system, meanwhile we keep the maintainability of the system.Fortunately, this purpose can be attained by use design patterns and design principles. Design patterns are the embodiment of design principles about concrete matters. UML (unified modeling language) is the symbol standard to illuminate design patterns and design principles so that software designers can intercommunicate ideas.Agent is also a software system that must comply with the regular design principles and use some appropriate patterns. This thesis analyses the agent framework based on the design patterns and design principles, while prevenient researches focus the attention on the point view of artificial intelligence. This thesis makes great efforts to improve the design of agent in order to get the better reusability and maintainability.