Every time you walk the shop floor, you should take note of which machines are running and which ones aren’t. Ideally, you should find only two reasons why a machine is sitting idle (other than having no work for it). One: it’s in setup – and the setup person is actively working to complete the setup. Two: the operator is loading parts, and will be able to run the next cycle immediately after doing so.
If you find other reasons why machines sit idle, it should be taken as a signal that the machine is being under-utilized. That is, it could producing more. It is not living up to its full potential.
In the real world, this can be difficult to achieve. We tend to place personnel utilization (getting the most from our people) at a higher priority than machine utilization (getting the most from our machines). Machines often sit idle because their waiting on people. It’s as simple as that.
Why are machines waiting for people? We’ve probably heavily loaded setup people and operators with many responsibilities. They’ve got so much to do that they can’t keep up with the machines they run.
Operators, for example, probably have to load and unload parts, clean and debur parts, measure them, report to an SPC system, make offset adjustments, do paperwork, and perform preventive maintenance on the machine. Oh yeah – then we expect them to run two or more machines.
Setup people, on the other hand, may be responsible for several machines, and if two machines complete a production run at the same time, one of them – of course – will sit idle waiting for the setup person to complete the setup on the other.
If and when you’re faced with improving your company’s output (becoming more productive), one great – and usually easy – way to get better is to minimize or eliminate all but the two reasons just given regarding why machines sit idle.