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Understanding lead time and critical path


Lead time: How long it takes for a part to arrive once you have ordered it.

Critical Path: A list of jobs or stages, each one dependent (unable to start) until the previous stage has been completed.

Time, we discover, does not equal output. Quality aspects aside, two people given the same amount of time will produce vastly different quantities of final product. Two simple concepts to apply to your next (or current, or long overdue) project are lead time and critical path.

Lead time is lost time. Ordering a spare on Saturday morning is not much use if you need it that weekend. Sitting around waiting for things to arrive is not productive. Lead times are often connected to "preparation" and many of these steps can be moved out of weekend time and into the weekday. For example, it may take 10 minutes to find a spare part online, then 4 days for delivery.

The Critical Path shows you which stages must be completed before the next stage can be started. Two or more stages may be able to be done in parallel (simultaneously). Some processes are not on the critical path at all, meaning they can be done at any time without affecting other steps.

Map out the steps of your next project and think about which stages can be moved around. There are some stages that are on the critical path and have significant lead times attached (like waiting for a coat of paint to dry). However, many steps can be brought forward, broken up or rearranged to get maximum value out of your offpeak time - and in turn set you up for a productive weekend.
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