Method and apparatus for improving manufacturing processes

A method for scheduling and operating a factory having a plurality of workstations, each workstation performs one or more processes, each process operating on a batch of material, the method comprising the steps of:

• determining the rate of material flow out (FLOWOUT.sub.ij) of each process within each workstation of a factory for the factory to meet predetermined shipping rates;
• determining the cycle time CT.sub.j for each workstation j to process a batch of material based upon the following relationship:
• CT.sub.j =[.SIGMA.SUeff.sub.ij ]/[1-.SIGMA.(Peff.sub.ij)(FLOWOUT.sub.ij)]
• where, for process i within workstation j, SUeff.sub.ij is the effective set-up time, Peff.sub.ij is effective time to process one unit of material, FLOWOUT.sub.ij is the material output flow rate, and n is the number of processes performed by workstation j;
• and
• identifying inefficient workstations having the longest cycle times by an evaluation of cycle times and batch sizes;
• and
• operating the processes performed by the identified workstations having the longest cycle times to reduce the batch size and cycle time of the identified workstations.

A factory for manufacturing and shipping goods, the factory comprising:

• a plurality of workstations, each workstation performing one or more processes, each process processing a batch of material having sizes determined by a system for scheduling manufacturing processes to meet a shipment schedule;
• and
• a system for scheduling manufacturing processes to meet a shipment schedule, the system including:
• a memory for storing data values of variables received from the factory representing shipping rates of a mix of products produced by the factory, processing times per unit of material for each process in each workstation and set-up times for each process in each workstation;
• a microprocessor, coupled tot he memory, for determining the rate of material flow out of each process within each workstation necessary for the factory to meet the shipment schedule and for determining the size of the batch of material for each process of a workstation necessary to meet each material flow rate out of each workstation for each process;
• and a means for providing the batch size for a process to the factory.

A factory production scheduling and organization process, the process outputting information for optimizing production scheduling and organization and improving the efficiency of a factory production line to meet a predetermined shipping rate, the factory production line comprised of a plurality of interconnected workstations each performing at least one process, comprising the steps of:

• receiving factory production line organization and operation data;
• modelling the factory production line, according to the input factory data, by generating flow rates of material through each workstation for each process and processing capacities of each workstation for each process to meet the predetermined shipping rate for the production line;
• analyzing the factory model according to the factory data and generated workstation material flow rates and workstation processing capacities for each process to evaluate workstation performance, process and production line performance, and identify optimal production line operating and supply characteristics;
• and
• operating the production line to implement the identified optimal production line operating and supply characteristics to substantially meet the predetermined shipping rate.

A method for analyzing the scheduling and organization of production for a factory, the method outputting information on optimizing factory production scheduling and organization to meet a predetermined shipping rate, said factory comprised of a plurality of workstations each performing at least one process, comprising the steps of:

• receiving factory organization and operation data comprising workstation processing times and workstation set-up times for each process;
• modelling the factory according to the input organization and operation data by:
• (1) determining the effective processing time for each workstation to process one unit of material according to a given process;
• (2) determining the effective set-up time required to configure each workstation to change between each process performed by the workstation;
• (3) determining the flow rates of material in and out of each workstation for each process required to output material from the factory meeting the predetermined shipping rate;
• and
• (4) determining the production capacity of each workstation to handle material flow rates in and out of each workstation for production of material units at the rate necessary to meet the predetermined shipping rate;
• and
• analyzing the production performance and efficiency of the factory by:
• (1) evaluating the material flow rates through each workstation for each process cycle time between processes for each workstation to identify optimal material supply requirements for each workstation necessary to meet the predetermined shipping rate;
• (2) simulating factory operation at peak capacity levels by scaling material flow rates through each workstation to capacity levels and evaluating the material flow rates and process cycle times at peak capacity levels to identify inefficiently operating workstations and processes to establish improvements in factory organization and operation;
• and
• operating the plurality of workstations to implement the established improvements in factory organization and operations on factory production facilities.

A method for improving the performance of a factory having a plurality of workstations performing one or more processes, each process operating on a batch of material, the method comprising the steps of:

• determining the batch size of material required by each workstation j to perform each process i;
• determining a cycle time (CT.sub.j) for each workstation j to process the material;
• evaluating the cycle times and batch sizes to identify inefficient workstations and improve the processes performed by each workstation in order to reduce the batch size and cycle time of that workstation;
• and
• operating the processes of the identified inefficient workstations to implement the improvements identified as a result of the evaluation of the cycle times and batch sizes.