The use of traditional production planning techniques is constrained by large numbers of decision variables, uncertainty in demand and time production, and non-deterministic system behaviour, characteristics intrinsic in manufacturing. The aim of this paper is to present a methodology that combines the modelling power of petri-nets (PN) to represent both manufacturing architecture and production logistics, together with the optimisation performance given by constraint programming (CP). While PN can represent the entirety of any system, CP is effective in solving large problems, especially in area of planning. The foundations to generate a Constraint Satisfaction Problem (CSP) from a PN are given.