Reconfigurable manufacturing systems can change the structure of the systems to cope with manufacturing market requirements. Reconfigurability brings about new challenges for reconfigurable manufacturing systems' development. In order to describe, analyze, and verify the reconfiguration of reconfigurable manufacturing systems, a reconfigurable manufacturing system formal model is proposed from the perspective of multi-agent systems, in which two complementary formalisms, namely, object-oriented Petri nets and p-calculus, are employed as formalisms. The object-oriented Petri nets are utilized to model the initial structure as well as system behaviors of reconfigurable manufacturing systems, while p-calculus is adopted to describe the reconfiguration of reconfigurable manufacturing systems. Some supporting tools of Petri nets and p-calculus can be used to analyze, verify, and validate the reconfigurable manufacturing system formal model. The reconfigurability mechanism and consistency of reconfigurable manufacturing systems can also be analyzed by p-calculus.