In the field of Business Process Management formal models for the control flow of business processes have been designed since more than 15 years. Which methods are best suited to verify the bulk of these models? The first step is to select a formal language which fixes the semantics of the models. We adopt the language of Boolean systems as reference language for Boolean process models. Boolean systems form a simple subclass of coloured Petri nets. Their characteristics are low tokens to model explicitly states with a subsequent skipping of activations and arbitrary logical rules of type AND, XOR, OR etc. to model the split and join of the control flow. We apply model checking as a verification method for the safeness and liveness of Boolean systems. Model checking of Boolean systems uses the elementary theory of propositional logic, no modal operators are needed. Our verification builds on a finite complete prefix of a certain T-system attached to the Boolean system. It splits the processes of the Boolean system into a finite set of base processes of bounded length. Their behaviour translates to formulas from propositional logic. Our verification task consists in checking the satisfiability of these formulas. In addition we have implemented our model checking algorithm as a java program. The time needed to verify a given Boolean system depends critically on the number of initial tokens. Because the algorithm has to solve certain SAT-problems, polynomial complexity cannot be expected. The paper closes with the model checking of some Boolean process models which have been designed as Event-driven Process Chains.
最近的研究表明，分支双相似性是可判定的nBPP（赋范基本并行进程）和nBPA（赋范基本进程代数）。这些结果导致的问题，如果有任何其他模型的PRS（过程重写系统）的层次结构的分支双相似性是可判定的。本文证明了nOCN（normed One Counter Net）和nPA（normed Process Algebra）的分支双相似性是不可判定的。这些结果基本上意味着这个问题有一个否定的答案。
