Production planning approaches considering availability of complete information, usually fail to deal with real manufacturing environments characterized by uncertainty affecting the time to execute the manufacturing operations, the routing of the parts, the requirement of materials and resources. This paper analyses the problem of negotiation and planning of external resource usage in a manufacturing system affected by uncertainty. In particular the need of resources is considered uncertain and it is modelled through a scenario based formulation. A rolling horizon approach is proposed which applies a two-stage stochastic programming method against the occurrence of multiple uncertain events.To demonstrate the viability of the proposed approach, an application example based on a real manufacturing plant producing machining centres is provided. © 2007.