Benchmarking is currently one of the most effective industrial performance improvement processes. For the company, it is a question of observing, adopting and/or adapting best practices, and this with the aim of improving the performance of some of its processes. The realization of benchmarking, whether it be internal or external, is not however without its difficulties. The first difficulty for the company is to manage to clearly define what a best practice is. We thus built a typology of best practices which could help to discern more effectively what could be relevant to exchange in benchmarking. The second difficulty for the company is to identify its best practices. The BPS method (Best Practice Specification) which we describe in this paper allows the company to locate and to specify the good practices likely to be transferred within the framework of benchmarking.