Monitoring and Scheduling Methods for MIMO-FIFO Systems Utilizing Max-Plus Linear Representation

This paper proposes an approach to monitoring and scheduling methods for repetitive MIMO-FIFO DESs. We use max-plus algebra for modeling and formulation, known as an effective approach for controller design for this type of system. Because a certain type of linear equations in max-plus algebra can represent the system's behavior, the principal concerns in past researches were how to solve the equations. However, the re- searches focused mainly on analyses of the relation between inputs and outputs of the system, which implies that the changes or the slacks of internal states were not clarified well. We first examine several properties of the corresponding state variables, which contribute to finding and tracing the float times in each process. More- over, we provide a rescheduling method that can take into account delays or changes of the internal states. These methods would be useful in schedule control or progress management.