Method and apparatus for controlling product routing in a manufacturing line

Within a manufacturing line wherein a plurality of production jobs are performed on a plurality of production units in a plurality of processing areas, a system for diverting a number of said plurality of production units to a designated area other than the plurality of processing areas, comprising:

• a first clock which measures a first time interval beginning every time a production unit is diverted to the designated area, wherein said first clock also outputs a first time interval signal having a value representing said time interval;
• a unit bypass counter which outputs a unit bypass count signal having a value representing the number of production units that have bypassed the designated area since the last production unit diverted to the designated area;
• a selected unit counter which outputs a selected unit count signal having a value representing the number of production units diverted to the designated area;
• a memory containing a preset value for said unit bypass count, a preset value for said selected unit count, and a preset value for said first time interval;
• a controller connected to said memory, said first clock, said unit bypass counter and said selected unit counter, said controller including a comparator for comparing the signal from the unit bypass counter, from the selected unit counter, and from the first time clock to the respective preset values stored in said memory, said controller also including a unit selection device to divert one of the plurality of production units to the designated area, when:
• either the value of said first time interval signal is greater than or equal to the preset value for said first time interval, and the value of said selected unit count signal is less than the preset value for said selected unit count;
• or
• the value of said unit bypass count is greater than or equal to the preset value for said unit bypass count, and said selected unit count signal is less than the preset value for said selected unit count.

A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the method steps for diverting a number of a plurality of production units to a designated area other than a plurality of processing areas, said method steps comprising:

• a) counting the number of production units that bypass the designated area beginning every time a production unit is diverted to said designated area, to obtain a unit bypass count;
• b) counting the number of production units diverted to the designated area to obtain a selected unit count;
• c) measuring a first time interval beginning every time a production unit is diverted to said designated area;
• d) comparing the unit bypass count, the selected unit count and the first time interval to a preset value for each of said unit bypass count, selected unit count and first time interval respectively;
• and:
• 1) diverting one of said plurality of production units to the designated area when the measured first time interval is equal to or greater than the preset value for the first time interval and the selected unit count is less than the preset value for the selected unit count;
• or
• 2) diverting one of said plurality of production units to the designated area when the unit bypass count is equal to or greater than the preset value for the unit bypass count and the selected unit count is less than the preset value for the selected unit count.