During the frozen time period for the MRP production schedule, changes in the production plan are typically not allowed. True or False?

True! That's why it's called the "frozen period"; it's like your plans are frozen in place, unable to move. Another common term is time fence; I like to imagine it as a fence that you need to climb over to reach the other side.The reason you have a frozen period is that changing schedules is costly; you don't want to be constantly shifting back and forth at the drop of a hat. The...

True! That's why it's called the "frozen period"; it's like your plans are frozen in place, unable to move. Another common term is time fence; I like to imagine it as a fence that you need to climb over to reach the other side.

The reason you have a frozen period is that changing schedules is costly; you don't want to be constantly shifting back and forth at the drop of a hat. The optimal length of your frozen period will depend on how costly it is to change strategies; as technologies like 3D printing and just-in-time manufacturing get more commonplace, this switching cost might actually get so low that there's no need for a frozen period, or at least make it extremely short.

That doesn't mean that you stop thinking about your plans during the frozen period; in fact, it's quite typical to observe what is and isn't working during the frozen period and use it to plan the schedule for future periods. But the idea is that unless you have a really compelling reason, you don't try to change the plan for this particular run while you're still in the frozen period, because the change would be too costly.