What is just-in-time (JIT) production? How does a JIT system help managers minimize inventory costs?

A just-in-time (JIT) production system is a method of inventory control in which materials are acquired and put into production at precisely the time they are needed. The system helps managers minimize manufacturing inventory costs because:
-All resources are continuously flowing, from their arrival as raw materials to subassembly, final completion, and shipment of finished products
-JIT reduces to practically nothing the number of goods in process and saves money by replacing stop-and-go production with smooth movement
-Once smooth movements become the norm, disruptions become more visible and thus are resolved more quickly
-Finding and eliminating disruptions by continuous improvement of production is a major objective of JIT