Software process modeling has attracted much research effort in Software Engineering. However, there is little work reported for the verification of process models. In fact, the verification is often either performed by hand or it is left to the enacting mechanism to detect inconsistencies during execution. Since process models are becoming more and more powerful and complex, their verification is also becoming increasingly difficult and critical. Our proposition is that in the same way as we need process modeling to facilitate software manufacturing, we need special tools to help verify the consistency of software process models. This paper presents part of our research and our experience in designing and prototyping such a tool for the verification of software process models in the ALF project (Esprit No.1520). The tool helps verify the partial consistency of process models by statically detecting various inconsistencies. This prototype uses techniques developed in different fields such as compilation, constraint solving and logic. To our knowledge, this is the first tool of its kind designed for the static checking for process models.