> The problem is that these refrigerator cases are not as simple as your refrigerator at home. As a simple example, many systems allow you have control over the deadband: the exact low temperature at which the compressor turns off and the high temperature at which the compressor turns back on. You also have control over defrost cycles, compressor pressure and many other things (I worked with this a long while ago, and I don't remember all the details). … This is not something that a non-expert supermarket employee would be able to handle well.

I still don't see why the expert has to be remote, or why an integrated computer can't do the optimization. Or why it needs to be fiddled with at any significant frequency.