This paper reviews a proposal for the modular analysis of Petri nets and its applicability to factory automation systems. It presents new algorithms to harness this modular analysis in the determination of reachable states with specified partial markings, to determine possible deadlocks, both global and local, and also liveness. These algorithms have been implemented in a prototype tool which has then been used to solve a problem in factory automation which, even for relatively simple configurations, can lead to state spaces beyond the capabilities of many analysis tools.