An error-comprising workflow dejinition might provoke serious problems to an enterprise especially when it is involved with mission critical business processes. Concurrency of workflow processes is known as one of the major sources causing such an invalid workflow process definition. So the conflicts caused by concurrent workflow processes should be considered deliberately when dejining concurrent workflow processes. However it is very dificult to ascertain whether a workflow process is free from conflicts or not without any experimental executions at runtime. Which will be very tedious and time consuming work to process designers. If we can analyze the conflicts immanent in concurrent workflow definition prior to runtime, it will be very helpful to business process designers and many other users of workflow management system. In this papel; we propose a set-based constraint system to analyze possible read-write conflicts and write-write conflicts between activities which reads and writes to the shared variables in a workflow process dejinition. The system is composed of two phases. In thejirst phase, it generates set constraints from a structured workflow dejinition. In the second phase, it jinds the minimal solution of the set constraints.