The main aim of Enterprise Architecture (EA) is to master the development and the evolutions of Information Systems (IS). The EA process consists of designing the IS target architecture from several views, according to the company strategy. The business view represents the target organization of the particular company. The functional view focuses on the target functional architecture of that company’s IS. In this paper, we propose a new formal solution to analyze and to improve the consistency between the target functional view and the target business view of telecom services. This solution is based on the definition of a strategic alignment of the target functional view with the target business view. Alignment is validated with a real case study implemented and deployed at Orange--France Telecom on their messaging service. An alignment measure completing this analysis provides an estimation of the gap between a target functional view and a target business view.