A Single Machine Scheduling Problem with Discrete Machine Conditions In a real workshop, machine condition is an essential constraint to achieve an overall scheduling optimization. This paper studies a single machine scheduling problem with discrete machine conditions constraint and maintenance consideration. The scheduling sequence decides the actual processing time of jobs by the processing position in scheduling sequence. A tradeoff exists between the rejection of maintenance resulting in longer processing time and acceptance of maintenance leading to the delay of future jobs. A finitehorizon Markov decision process models the problem to minimize the makespan. An optimal scheduling decision sequence is developed to deal with the dynamic evolution. Computational experiments are conducted to evaluate the proposed approach.

Optimal Production and Maintenance Scheduling for a Multiproduct Batch Plant Considering Degradation Abstract   Performance decay due to asset degradation is an important constraint in industrial production and therefore needs to be actively considered. This paper focuses on shortterm scheduling for multiproduct batch processes with sequencedependent degradation and is motivated by a case study in which the sequence of multiplegrade batch runs impacts evolution of fouling. A continuoustime scheduling formulation is proposed to incorporate realistic features of the case study processes. The precedence scheduling concept for the sequential process is employed to model sequences of multiproduct orders and maintenance and is implemented using the general disjunctive programming method. The scheduling formulation is applied to the case study and further analyzed through comprehensive computational tests, which illustrates the efficacy of the proposed formulation.