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Labor content, cycle time and idle time


Cycle time, labor content and idle time are indicators for assessing the productivity of a process.

Cycle time: The cycle time is defined as the time between the output of two successive flow units (e.g. the time between two served customers or two treated patients). It is always equivalent to the time of the longest process step.

Total labor content: The total labor content is defined as the time sum of all process steps. If, for example, a process consists of two steps each claiming 20 seconds, the total labor content is 40 seconds.

Idle time: The idle time is defined as cycle time minus processing time. The idle time thus tells us for how long a resource (e.g. a worker) is not able to do anything, because he has to wait for another resource. If, for example, one worker in a sandwich restaurant prepares sandwiches while another operates the register, the second worker has to wait for a sandwich to be finished in order to collect on the customer. If the demand is maxed out, the idle time at the bottleneck is always 0.

Total idle time: The total idle time is the time sum of all idle time within a process.

These lecture notes were taken during 2013 installment of the MOOC “An Introduction to Operations Management” taught by Prof. Dr. Christian Terwiesch of the Wharton Business School of the University of Pennsylvania at


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