Design patterns are also used to increase the reusability as rup advocated . the abstract factory , observer and iterator patterns is introduced Rup过程鼓励复用，设计过程中使用很多设计模式来增加复用性，如抽象工厂、观察者模式和迭代器模式等。
Instead of using a tangle of abstract factories , service locators , singletons , and straight construction , each object is constructed with its collaborating objects 没有使用一堆抽象工厂、服务定位器、单元素（ singleton ）和直接构造（ straight construction ） ，每一个对象都是用其协作对象构造的。
Abstract factory pattern and reflection technology was used for strategy analysis and dynamic module call . details of the above mentioned study are described in the thesis . then , the expandability of the intperida system is discussed Intperida系统中身份鉴别策略解析和动态模块调用的实现采用了抽象工厂模式和反射( reflection )技术,本文对此进行了深入研究并进行了实际应用。
Second , improving the original design , include building the inheritance system for applicaion sheets , making strategy for a new flow node , and supporting the various database connections . we implemente the tasks by using three design patterns , they are abstract factory pattern , strategy pattern and template method pattern 第二，改进设计，主要是建立申请单的继承体系，为新建审批节点制定策略和支持连接到不同的数据库。这是通过三个设计模式来实现的，分别是抽象工厂模式，策略模式和模板方法模式。
