I golf maybe once a year, and go through 20+ balls in a round. But my score always looks good because I must confess, I take a lot of mulligans and gimme putts. I also fudge my handicap, so if you were to go by the numbers alone, I really do look good at golf. But as I said, I am terrible.
OEE can be the same way.
Are OEEs well above 85%? Are targets beaten most hours? That would indicate that on paper, plant performance is very good – world class, in fact! However, these figures may provide a false sense of complacency, and actually hide improvements that could be made (just because on paper, the plant is performing well.) But before the world class title is bestowed, let’s make sure there aren’t any mulligans, gimme putts…or fudged handicaps.
If lines run through breaks/lunches and the target / scheduled minutes doesn’t increase then the plant isn’t counting those minutes in the OEE calculation and is taking a mulligan.
Are cycle times faster than what is used as the ideal cycle time for OEE? Consistently beating hourly targets? By definition this shouldn’t be theoretically possible but it happens and in this way the plant is fudging its handicap.
Plants don’t set out intentionally to game the system but with the constant change that happens on the plant floor taking a mulligan or fudging the handicap happens frequently. Maintaining the schedule to include the breaks/lunches that were run in the calculations is forgotten or overlooked. Ideal cycle times get set on customer demand or initial projections rather than theoretical maximum capacity.
What plants need is a tool to help eliminate the mulligans and fudged handicap so the score can be trusted. A tool that dynamically detects production during unscheduled times (breaks/lunches) and adjusts the scheduled in real time and that uses the data collected to determine historically what the best hour of production was and how far out the current Ideal Cycle Time is from reality.
That tool exists, ask me about it, but don’t ask me about my golf game.
Mike Comello, P.Eng. – Senior Project Manager