Cycle times will often be very much smaller than lead times. For example, in one recent process examined, the average wait to start treatment was 214 days, but the sum of the cycle times – the time taken for all of the processes that lead up to treatment starting – was about three and a half hours. There was definite waste within individual processes – at least half an hour and probably more – but by far the largest waste was the waiting time between the cycles. You can then use your measurements to identify value to the patient by working out the value added time as a proportion of the total lead time. All of the waiting between cycles was of no value to the patient, and some of the work within cycles was also of no value. When worked out as a percentage, about % of the lead time was of value to the patient. So, I use lead time for the total length of the process of interest, and cycle time for the length of individual activities – what Shigeo Shingo would have called operations. The degree to which I break down these operations in to smaller stages would depend on the improvement work on which I was engaged.
OK, I see it. There is unfortunately some confusion in the wording. For me, cycle time is the time needed at one process to make one product. What you are asking for is either the total work time, or the line takt (in my wording). Please note that unfortunately there is no nomenclature, and everybody means something different when talking about cycle time. See my post On the Different Ways to Measure Production Speed . For you, both ways can be calculated, the important question is: What do you need the number for? If management just wants a number, just give them a number.
(land, buildings, equipment) provide the physical capability to add
value and create products. The most common manifestation of
facility planning (or lack thereof) is the Plant Layout . An effective layout incorporates and enables the manufacturing strategy on which it is based. Lean strategy starts with workflow and
workflow is the result of process and layout. Mr. Lee has authored two books and many articles on Plant Layout
and Facility Planning. His approach is organized, practical and systematic.