What do we mean by "Push" in Lean material management?
This article defines and gives an example of what is meant by "Push" in the world of Lean Material Management.
Textbook Definition of Push
When you are pushing work or material, you are simply following a plan or schedule, and moving material to the next step without considering whether it is needed at that next step right now or not. Your measure of success in a Push environment is schedule adherence for your department. Whether the material is needed at that moment is not your concern.
Let's now look at an everyday example of the Push method, used in making sandwiches for sale.
Common Examples of a Push Technique
In the Push example making sandwiches, you first need to take a guess at how many sandwiches you can sell today. As you know, forecasting is hard, especially when it’s about the future. The strategy is to make the sandwiches ahead of time, and have them available when the customer arrives.
You then make that many sandwiches, and put them on display in a refrigerated case. You would have had to procure the raw materials, the bread and ingredients ahead of time as well.
During the day people come in to buy them, you hope. You may have a pretty good idea of average sales, but sales on individual days will vary a lot.
At the end of the day, you have three possible outcomes:
- You sold exactly the number of sandwiches that were made. This is possible but unlikely.
- You overestimated and we have some left over. Since the shelf life is only one day, you’ll have to eat sandwiches for dinner, again.
- You underestimated the number of sandwiches. You could have sold more, so that’s a lost opportunity.
Who makes and sells sandwiches this way? Lots of outlets, including your local gas station, and supermarkets. This is what we call PUSH.