Although having no inventory is a goal that can never be attained, inventory is the enemy of quality and productivity. This is so because inventory tends to increase leadtime, prevents rapid identification of problems, and increases space thereby discouraging communication. The true cost of extra inventory is very much in excess of the money tied up in it.

"Just-in-time" (JIT) manufacturing has taught that inventory deliberately hides problems by covering them up. So, perhaps, a quality problem is not considered important because there are always extra parts available if one is defective. JIT encourages deliberate inventory reduction to uncover this sort of problem. Perhaps the safety inventory is deliberately cut. If nothing happens - fine, you have learned to operate with a leaner system. If stoppage occurs - good, because the problem has been recognised and can now be attacked at its root cause.

Examples: inventory exceeding specified quantity limit, so much inventory at workplace that double handling is needed, excessive safety stock.