Cumulative Percentage Loss I wondered if anybody knew how to calculate a percentage loss/gain of a process over time?
Suppose for example Factory A conducted activity over 6 periods.
In t-5, utilisation of resources was: 80%
t-4: 70%
t-3: 80%
t-2: 100%
t-1: 90%
t: 75%
Therefore, but for the exception of two periods ago, at 100% utilisation, there has been a utilisation loss. 
Is it possible to calculate cumulative utilisation loss over this period?
Any help would be appreciated, 
Best,
Andrew
 A: For each period, the loss is $100\%$ minus the utilization, so your losses are $20\%, 30\%, 20\%, 0\%, 10\%, 25\%$.  The total of these is $105\%$, which means that in the six periods you have lost just over one period of utilization.  If you average them, you get $17.5\%$, which means that you have lost that percentage of the possible utilization of the six periods.
A: For this example, just over 1 day production has been lost if you think of all days having similar normal production, as Ross Millikan's answer shows. Some processes compound though. If this were percentage left of a given stock value on each day without reset, then it works as follows:$$1\cdot0.8\cdot0.7\cdot0.8\cdot1\cdot0.9\cdot 0.75=0.3024=30.24\%$$ so your stock would be worth 30.24% of it's original value, having lost 69.76% of it's original value. If it were gains then without withdrawing any of it, it would be: $$1.8\cdot1.7\cdot1.8\cdot2\cdot1.9\cdot1.75 -1= 3562.82\%$$ There are more possible scenarios, but I think that is enough.
