灵活运用设计模式可以解决在软件维护性和复用性上存在的问题，其目标是为软件系统构建灵活的可扩展的设计方案。

The flexible use of Design Patterns can improve the reusability and maintainability of software. The goal of Design Patterns is to build an extensible solution for software systems.

结果往往是如同一个在超级市场购物的顾客结账时惊讶地发现，购物篮（我们可以将其比作软件维护的需求）中一些本来很便宜的货物算在一起居然是一个很大的数目。

Like in a supermarket the user is afterwards astonished that the many cheap goods in the basket (comparably maintenance requirements) cumulate to a large sum at the cash point.