Introduction The design of working places fitting for all the employees is a major issue for the prevention of health and safety. It is a double challenge: because of the target, the result of the design, but also regarding the methods of intervention. The management of changes is a way to promote a learning and collaborative organisation, and thus the role of the final users. The participation of the employees in the design process is an important issue to achieve these goals, but it is a complex process which needs several requirements. The involvement of employees can lead to failure if the conditions and the aim of the participation is not clear enough.

Methods An ergonomic intervention aiming the design of a reception desk for 280 agencies of a bank company has been carried out. After two attempts which led the company to a social conflict, they decided to start over the process with an ergonomist, with a different management. A steering group and a working group had been set up, simulations and test period had been carried out.

Results The result of the design and it acceptance by the employees show that the process is as important as the goal. We can attest that several conditions must be controlled: which structure of the project, who to be involved, how, for what regarding their professional position, with which knowledge of the real work situations?

Conclusion The way we build the interventions must be in link with our vision of the future operation and the place of the users in the organisations. The project structure must insure two goals: the involvement of the relevant managers and the participation of the employees concerned by the implementation, but with tools and a methodology. It is both a matter of efficiency and a dynamic for healthy organisations.