Firstly the designer must try and obtain as detailed a design brief as possible so that he designs what is actually required. This will inform him as to what is necessary and which parts are optional.

• 首先，设计者必须获得尽可能详细的设计任务书，这样他可以明确设计的要求。这会给他指明什么是必须的，哪些部分是可选择的。