The Origins of Just-In-Time
A couple weeks ago, the students in my ISAT 654 (Advanced Technology Management) class at JMU asked about where and when Just-In-Time (JIT) manufacturing actually started in the United States. Although I still can’t identify the FIRST company to adopt this approach, I was also curious about how the adoption of JIT in the US grew from the Toyota Production System (TPS).
Just-in-Time (JIT) is only one element of lean manufacturing, which is a broader philosophy that seeks to eliminate all kinds of waste in a process. Although JIT is often considered an enterprise-wide philosophy of continuous improvement, I’d like to focus on the mechanistic aspects of JIT – that is, the development and operations of a production system that employs continuous flow and preventive maintenance. In an effectively implemented JIT production system, there is little or no inventory – which includes Work-In-Process (WIP) – and production is tightly coupled to demand.
The origin of JIT can be traced back to Henry Ford’s production line, in which he was keenly aware of the burdens of inventory. However, Ford’s production system generated large volumes of identical products created in large batches – there was no room for variety, and the system was not coupled to demand levels.
In post-war Japan, Taiichi Ohno (“Father of JIT”) adapted the system at Toyota to handle smaller batch sizes and more variety in the parts that could be used to construct assemblies. In 1952, work on their JIT system was initiated, with full deployment of the kanban pull system by 1962. This was the genesis of the Toyota Production System, an elegant (and sometimes elusive) socio-technical system for production and operations. This approach bridged the gaps between production and continuous improvement and became the basis for lean manufacturing as it is known today.
After the oil crisis in 1973, other Japanese companies started to take note of the success of Toyotaand the approach became more widely adopted. The JIT technique spread to the United States in the late 1970’s and 1980’s, but due to inconsistencies in implementation and a less mature grasp on the human and cultural elements of the Toyota Production System, western companies experienced limited success. The Machine that Changed the World by James Womack made the JIT+TPS concept more accessible to US companies in 1990, which led to the widespread adoption of lean manufacturing techniques and philosophies thereafter.
JIT is very sensitive to the external environment in which it is implemented. For a review of Polito & Watson’s excellent 2006 article that describes the key barriers to smooth JIT, read Shocks to the System: Financial Meltdown and a Fragile Supply Chain.
(P.S. Why the picture of butter? Because JIT, when implemented appropriately, is perfectly smooth and slippery and thus passes The Butter Test.)