Patent ID: 7979151

Claim:
An automated manufacturing system, said manufacturing system comprising: a dispatch system comprising a scheduling unit, said scheduling unit determining a job order for processing multiple jobs, said jobs each comprising the same multiple consecutive process steps; a data storage device storing lists of processing tools, each list comprising at least one process-specific tool adapted to perform a specific process step, said dispatch system further comprising an assignment unit in communication with said data storage device, said assignment unit accessing said lists from said data storage device, and determining, based on said lists, possible combinations of process steps and tools for processing said jobs and randomly assigning, to each of said jobs, a specific combination of said process steps and tools selected from said possible combinations such that, as said jobs are processed in said order, said processing tools are evenly distributed across said jobs, and said data storage device further storing records of specific combinations of said process steps and tools employed to process said jobs; and a statistical process control (SPC) system identifying product variability at any specific process step, said statistical process control (SPC) system further being in communication with said data storage device, accessing said records of said specific combinations from said data storage device and determining, based on said records of said specific combinations, which specific processing tool used when performing said specific process step was a largest contributor to said product variability.