The present thesis is about the field of system engineering and innovation engineering. It took place in the financial industry within the group of banking insurance Groupama. Services represent 64% of world's GDP (Gross Domestic Product). This branch employed in 2007 in France about 20 million people against 5 million for industry. Still the research on the innovation processes presents a gap with only one NSD (new services development) article against four NPD (new products development). The aim of this work is to propose a method for management of innovation projects in the services branch. To formalize the management of innovation projects for the services, while preserving the space required for innovation, we use a NPD's type formalism in order to define a NSD process while respecting the specific flexibility of the innovation in the services branch. The center of our hypothesis was to identify invariants within the NSD process. We propose six classes of invariants: IDOs (Intermediate Design Objects), the resources, the skills, the tasks, the indicators and the methods. Theirs interactions are shown in a UML Diagram of Classes. A project may be represented as an "addition" of IDOs, where they are the result of 5 other invariants arrangements. These six classes of invariants were validated on Groupama projects. They are relevant to describe, monitoring, capitalize, re-use of the knowledge acquired on previous projects and to manage innovative projects as well. We also propose a process of piloting of the NSD projects, formalized by a Diagram of Phases Sequencing of MEGA.
