I. Introduction
In recent years, with the gradual mature and application of the new techniques such as software architecture, software components, software large granularity reuse etc., software engineering method based on product line have aroused broad attention of software engineering filed and already become the hot spot and priority of the current studies in software engineering field. The core of software product line studies is to apply the techniques of software architecture, software components, software large granularity reuse and realize the industrialization and automatic production of mass custom-made software products in a specific field, which is similar to product line automatic production modes of modern manufacturing industry products (such as cars, TVs etc.). This is the ideal software production mode pursued for 40 years of software engineering development, which has the very important effect on the formation and development of modern software estate, and will produce the gigantic society and economic effect. [1]–[3]