Integration, Verification & Validation processes are key activities regarding the Quality, Cost and Delivery time, and thus has a huge impact on the projects profitability. IVV processes are complex and have to take into account in a coherent way various elements such as skills, organizations, means, process and risk management. Therefore, a maturity model is well adapted to describe how to evaluate and improve an industrial context. In order to help managers to assess their IVV process and reach a performance level corresponding to their goal, an assessment notation has been carried out (IV²AN). As the main idea is to improve step by step and not to jump directly to the higher level, the assessment notation proposes some ideas for a smooth deployment to improve and gain in development performance. This paper describes this approach, based on criteria which seem important to the INCOSE's French Chapter (AFIS) IVVQ Working Group and shared by several industrial companies.