Of all the resources we have, time is truly the only one where there is no chance of technology making it replaceable or renewable. We all know that, so why do we continue to waste it so indiscriminately?
Seems to me the answer is that we cannot see it messing up the floor, count it as it comes back as rework, or feel as engaged as when something tangible disappears before our eyes. The passing of time is usually only noted in the past tense.
It makes sense therefore to manage time obsessively, simply because it is so hard to do so, and if it was easy, everyone would be doing it. This simple observation implies that time management may be the source of real advantage.
If you just take inventory for instance.
Inventory and WIP is a tangible measure of the time you have to pay somebody for the failure in your demand forecasting, and extended process times. If there is any truth at all in the cliché, “if you cannot measure it, you cannot manage it” then the greatest opportunity for improvement in most operations I have seen is in measuring, and as a result improving, the productivity of time that has already been paid for.