This paper introduces a networked approach to design and operate agile manufacturing systems, able to plan, control and manage contingencies in a dynamic environment, characterized by supply, process and demand uncertainties. The aim of this paper is to present the NetMan generic concepts developed to support networked manufacturing. This approach is based on a distributed cooperative vision of manufacturing systems. We first present NetMan as a network organizational strategy by introducing the essence of NetMan organizational entities (NetMan center). Three typical networked manufacturing organizations from our application field are discussed in terms of distributed responsibility, physical and informational flows. We then present the NetMan cooperative relationships strategy, as a conceptual approach to implement operational networks. We present in this part a four-tiers relationship foundation to guide operations. Finally, we address the NetMan operational strategy. We show how this networked cooperative approach can be used to plan and control activities, and manage contingencies in a very close-to-reality manner. The NetMan experimental application is based on a real manufacturing case from a world class bus manufacturer.