Optimization-based process scheduling method and system

A machine-readable medium including instructions stored thereon which when executed in a processing system, cause the processing system to schedule the processing of workunits by:

• defining a plurality of workunits and a plurality of processing stations, each workunit of the plurality of workunits containing one or more items to be serviced by at least one of the plurality of processing stations;
• aggregating the plurality of workunits into a discrete number of workunit type-service type groupings consisting of a workunit type combined with a service type, wherein a service type is a type of service to be performed on each workunit;
• allocating to each processing station a total processing time for each workunit type-service type grouping for which the processing station is qualified based on a constrained optimization of a first objective function which load balances the total processing time across the processing stations and minimizes a number of setups on the processing stations;
• disaggregating the plurality of allocated workunit type-service type groupings by assigning particular workunits to each processing station to achieve the allocated total processing time for of each processing station;
• and
• determining a relative staff time for each workunit assigned to each processing station to batch the workunit type-service type groupings on each processing station based on an optimization of a second objective function.

A system comprising:

• a workunit deposit area configured to store a plurality of workunits for processing;
• a plurality of processing stations configured to process the workunits stored in the workunit deposit area;
• a transport system for routing individual workunits of the plurality of workunits from the workunit deposit area to at least one processing station of the plurality of processing stations;
• and
• an optimizing scheduler configured to execute program instructions that cause the routing and processing of the workunits by the processing stations by:
• defining a plurality of workunits;
• aggregating the plurality of workunits into a discrete number of workunit type-service type groupings consisting of a workunit type combined with a service type, wherein a service type is a type of service to be performed on each workunit;
• allocating to each processing station a total processing time for each workunit type-service type grouping for which the processing station is qualified based on an optimization of a first objective function which load balances the total processing time across the processing stations and minimizes a number of setups on the processing stations;
• disaggregating the plurality of allocated workunit type-service type groupings by assigning particular workunits to each processing station to achieve the allocated total processing time for of each processing station;
• and
• determining a relative start time for each workunit assigned to each processing station to batch the workunit type-service type groupings on each processing station based on an optimization of a second objective function.