Talking about the reuse of the software, in fact, the structure of the software is generally hierarchical, for example, the bottom of the intermediate layer, the intermediate layer generally has a system layer, and there are still some of the system layers. The application, first understanding the software is hierarchical. Second, first of all, you have to do a good software multiplexing, you must have a considerable understanding of your field and knowledge, such as telecommunications industries, banks, financial industries, have a very good understanding of this industry.
Software multiplexed granularity, I will give an example, in the face of class or Class's multiplex is very low, and it is not advisable, what is going to be reuse, to reuse a good architecture or framework, reusable subsystem, Reuse components, etc., reused in these granularities is truly meaningful. I have written a book a few years ago on the software reuse. I wrote a little, it is very difficult to reuse it, it is in your organization, how to reuse in the project development, what is the part is Can be reused, can be partially impossible to reuse. The premise of judging is that there is a very good process for your software, and there must be a good architecture analysis and the mastery of the domain knowledge.
