Industrial Grade Production Monitoring System is a system linked to optical sensors on the production line which allows monitoring of production performance both on and off the shop floor. The System has the feature that for each production line the number of units which should have been made is calculated on an on going basis. The System is controlled by either a central PC or local controller and allows complete preprogramming of shift patterns and production rates. The Industrial Grade Production Monitoring System has the feature that slave line displays can be added on any line to replicate the information from the master display.