The time between recognition / origin of the need; through to usage or consumption is...

Explanation

There are different views of 'lead time'; in part depending on where you are standing. The QUESTION NO: refers to total lead time, sometimes referred to as 'true' lead time.

The other lead times all exist, in the eyes of the various parties to any particular transaction.

One should note that the internal lead time (ie within the buying organisation) is often much longer than the external lead time. The idea that 'procurement' or suppliers take a long time to process a re-quirement can be illusory.