The need for production systems that can react or respond to dynamic changes is continuously increasing because of the reduction of product life cycle time and the rise of competition. To improve responsiveness, we show that integrating the intelligence of the human operator into the system helps to face complexity. However, little work has been done about the optimization of such integration considering production system constraints (real time decision making, observability, etc.) and human operator constraints (mental workload, trust in management system, self-con®dence, etc.). This paper aims at discussing ways to take account of the cognitive abilities of the human operator and oers some advice on how to take accurately into account the integration of the human operator by the proposal of a set of global speci®cations. To illustrate how it is possible to contribute to the optimized design of a system based upon such speci®cations, we propose the concept of distributed production management system''. We ®rst address the spe-ci®c interface issue. A classical example of advanced display'' designed for continuous systems, that is, the Ecological Interface Design (EID) approach, is applied to discrete production systems. We show that such an approach is coherent with parts of the introduced speci®cations but can be adapted to large complex and discrete systems with diculty. To solve this issue, we propose the development of a distributed DSS where each local DSS integrates an advanced display and manages a set of production resources in cooperation with an operator, which reduces the global complexity.