According to the union decomposition technology of Petri net, this paper proposed a new method that decomposes an acyclic and multi-output net system into several single output subnets and proved its correctness. Firstly, the Petri net model for the fault diagnosis system of production manufacturing and E-commerce manufacturer was built up. Secondly, the proposed method was adopted to decompose the built Petri net model. Thirdly, the consistency between the subnets status after decomposition and the initial net status was verified by calculation. As a consequence, the paper presented a new fea...