Participatory design in lean production: which contribution from employees? For what end?

The proponents of lean production have pointed to the positive effects of the work organization on employees in terms of autonomy, enhanced skills and empowerment mainly by their participation into the continuous improvement of work process. But studies that have examined this issue suggest that the increase in autonomy is not sufficient to compensate for increases work intensity. Participatory design has grown extensively in manufacturing since the 1980's under the impulsion of the Scandinavian socio-technical system approach and it's central in the model of lean production performance. Its main objectives are to improve quality, increase productivity and safety through employee's participation to the reduction of non-value added activities, such as defined by lean production. In the line of the studies on participatory design and continuous improvement the present study examines the functioning of work groups, based on the kaizen model, the aim of which was to improve the proportion of "value-added activities" and working conditions, essentially physical constraints. The main results are consistent with the literature and show that accelerated forms of re-conception activities give employees limited room for maneuver to elaborate solutions based on the analysis of the real activity. This study is part of a broader initiative that goes in the direction of continuous improvement of the design process itself so that it integrates the real constraints of work and propose changes bases on work as it actually takes place, beyond pre-established performance goals bases on the reduction of "non added value activities".