Pull Systems are another very important Lean Manufacturing concept. Traditional manufacturing used the “push” concept, making large batches of product and “pushing” them to each downstream operation whether they are ready for them or not.
Push systems also often have products produced that are not sold.
Ideal Pull Systems start at the opposite end, the customer, and once the customer signals an order, that last process signals to the upstream process to produce product. Each upstream process receives the signal (order) from the downstream process that it needs product, all the way back to the supplier of raw material.
Idea pull systems do not produce to inventory. Lean manufacturing concepts teach why inventory is one of the largest wastes in a company. Inventory costs money to purchase which raises the working capital necessary to run a business.