More Cycle Time Questions from Search Results

A couple of more exam questions showed up in search results.

4. what can happen if the cycle time is much shorter than the takt time

The searcher didn’t even bother typing this one – just cut and paste the entire thing, including the question number.

Fortunately the answer is really easy:

Raiders of the Lost Ark warehouse

If you keep this up, you’ll need another building.

OK, here’s one that is a little more subtle:

185 units in 14 hours is what cycle time

Hmmm. My first thought is to go back to Who is Grading the Questions?

think whoever wrote this question is looking for something like 14 hours  (840 minutes) / 185 units = 272 seconds / unit (more or less). But that’s an average, it isn’t a cycle time.

The Average Rate of Output is not “Cycle Time.”

The average doesn’t give you any more information than the original question. This is simply a rate of output: 185 units in 14 hours. Cycle time is the measured time to complete one cycle.

There might be a single cycle that produces a batch of 185 units. Let’s say, for example, in a cure oven process that takes 14 hours to load, run and unload. Then the cycle time is 14 hours.

If the pieces are moving in a sequence of operations, but in a lot (which is different from a batch), where Operations 1 is completed on all 185, then Operation 2 is completed on all 185, etc. and maybe that all takes 14 hours? I have no idea what the cycle time(s) for the operations are. Most of the time the units are waiting in queue for the other 184 items to be done at each operation.

If we have true one-by-one flow then I have at least 185 cycle times. Hopefully they are all about the same, but likely that isn’t the case.

Are we measuring exit cycles (the cadence of output at the end of the process), or operator or machine cycle times?

By taking the average we are obscuring all of this information. Calling the average the “cycle time” just makes it worse because it gives people the impression that they are the same.

Cycle time is not calculated. It is measured. You cannot determine cycle time by applying mathematical operations on numbers. You have to go observe with a stopwatch.

And finally:

within each four hours worked, workers can take a total of 48 minutes in allowance (so allowance factor is based on workday). if the observed time is 6 minutes, and performance rating is 95%, what is the standard time (in minutes; give three significant digits after the decimal point)?

Even if I could understand the question, down to thousandths of a minute? Seriously?

</rant> <!– Until next time –!>

 

 

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