Push versus Pull Production

In Just-in-Time work systems, the terms 'push' and 'pull' are often misinterpreted to mean that people need to come get their work because its there or the act of pulling work between stations. The common understanding usually shared is that a 'push' system is one in which production is made according to a forecast, before an order exists, and is therefore pushed to the customer while the production schedule of a 'pull' system consists completely of customer orders.

Rather, these terms refer to the context of a work flow control system that effects performance. In a 'pull' system, information related to the status of work-in-process, that is information from within, is used to authorize or trigger the movement of work within the system. Commonly this involves but is not limited to use of a Toyota-style 'production kanban' or visual card.

Therefore a 'pull' system establishes an internal limit on the work-in-process while a 'push' system does not. This is because in a 'push' system work is released on the basis of external information from outside the system without a feedback loop communicating the status of work-in-process. This results in no control on the fluctuation of work-in-process. In a manufacturing system the advantage of a 'pull' system is the promotion of a continuous flow in relation to inventory in the buffers between work stations.

In reality, most production systems are hybrids of 'push' and 'pull' with external and internal signals to authorize production or the release of work.

To create a 'pull' production system in healthcare work processes is challenging. So now you know why its easy to confuse 'pull' with the physical act of 'come and get it'!