An inventory strategy companies employ to increase efficiency and decrease waste by receiving goods only as they are needed in the production process, thereby reducing inventory costs.

This method requires that producers are able to accurately forecast demand.

Investopedia Says: A good example would be a car manufacturer that operates with very low inventory levels, relying on their supply chain to deliver the parts they need to build cars. The parts needed to manufacture the cars do not arrive before nor after they are needed, rather they arrive just as they are needed.

This inventory supply system represents a shift away from the older "just in case" strategy where producers carried large inventories in case higher demand had to be met.