Restart policies to maximize production quality in mixed continuous-discrete multi-stage systems

In sectors as semiconductor fabrication, pharma industry and food production, discrete production processes are intertwined with continuous production processes. Since continuous processes frequently produce large batches of material requiring fairly long processing times, restart policies aiming at scrap reduction especially due to work-in-progress perishability are commonly used to control the material flow in multi-stage production systems. A performance evaluation model integrating control mechanisms is proposed to assess the impact of local restart policies at system level. A real case study in the food production is presented, where the parameters of restart policies are optimized to maximize production quality.