Every activity can be broken down in process or seris of tasks creating value, and one or more support process. Analysis of these tasks reveal some of them are realy useful, because creating value, while other are realy useless, because they don't create value but consum energy and ressources instead, typical wastes. Hence, lead time is extended by these useless activities, delaying the value delivery to clients.

A lean process is a now "slender" process which was lightened of wastes and excess inventories which made it obese and less performant.

No client, if he knew, would accept to pay premium for products and/or services he "buys" to compensate inefficiency of his supplier. The inefficient supplier will not reveal his own poor performance, but competitors will, proposing better products at lower costs in faster delivery.