Question

OVERALL EQUIPMENT EFFICIENCY

A CNC machine tool is used for single shift working, the machine tool is operated for 8 hours per shift for 5 days per week. The CNC machine fool produces terminal blocks at a planned production rate of 60 units per hour Using the Availability, Performance and Quality losses given in the table below, (all values are in minutes per week) Calculate the average Overall Equipment Efficiency (OEE) for the machine tool over the three week period and using the principle of 'Best of the Best the expected increase in revenue during these three weeks if achieved. Assume the sales value of a terminal block to be 10 each Week Quality Losses No. Availability Losses Performance Losses 1150 320 1000 400 1180 190 240 120

Answer 1

Using the data given the total losses per week is the sum of all losses taken separately. Hence Total losses= Week 1 Loss + Week 2 Loss + Week 3 Loss = (1150 + 320 + 190) + (1000 + 400 + 170) + (1180 + 240 + 130)

=1660 + 1570 + 1550 = 4780 minutes. Total minutes available in a 5 day week operating 8 hours per shift = 60*8*5*3 = 7200. Hence equipment efficiency = (7200 - 4780)/7200 = 33.6%

If 100% efficiency is achieved then the lost 4780 minutes are made up at 60 units per hour giving us 4780 additional units. Hence increase in revenue = 10*4780 = $47,800.