Join Steven Brown for an in-depth discussion in this video Just in time, part of Lean Six Sigma Foundations.
- Can you imagine a world in which you receive everything you need, exactly when you need it? Not early, not late, only when you need it. Well, that's what Just in Time is all about. Although the Just in Time or JIT strategy is most often associated with Japanese manufacturers, Henry Ford is considered the father of Just in Time in the United States. Simply put, Ford did not believe in using warehouses. He bought material to fit the production plan.
Only enough to meet immediate needs. Ford recognized that transportation was a critical factor for success in such a strategy. So he owned a private network of railroad cars and trucks to ensure smooth delivery of materials. Just in Time was reintroduced to the U.S. as a best practice in the 1980s when Toyota and other Japanese companies were excelling in all manufacturing industries and capturing a large share of worldwide markets with their products.
JIT means that raw materials, components, and subassemblies are delivered to the factory just when they are needed for production. This allows inventory to be maintained at minimal levels, thus reducing cost and increasing flexibility within the system. Should an item become obsolete or a defect is discovered, with minimal inventory, it is much easier and quicker to make the needed adjustments. JIT is applied within the factory itself, also.
Work is not started into the factory until there is actual or forecasted demand for the final product. This is commonly called the pull system in that it is customer demand that drives the output of the factory and all its internal operations. This is a very important concept to recognize because for decades, most industries in America, including automobile manufacturing, were run on business accounting principles. Maximizing the output of an expensive machine meant you could spread those capital costs over more products.
So companies ran their factories at maximum production levels and hoped to sell all the product they made during the year. In the automobile industry, with new models introduced every year, it created surplus inventory throughout the supply chain. JIT changed that approach significantly. Under JIT, work-in-process inventory is only moved from one work station to the next when it is needed. This is commonly controlled by a kanban system. Kanban means sign or signal.
And the system uses a basic communication device, often just a simple card, to notify each work station when more inventory is needed. The card signals the work station to produce and forward a specified amount of inventory just in time to the next work station. Total inventory is reduced and throughput is increased, helping to reduce cost through a much more efficient system. There are several key considerations to keep in mind here. A JIT strategy is highly dependent on an effective delivery system, as Henry Ford recognized.
The further away your suppliers are, the more difficult it is to deliver just in time. One of the reasons Japan has been so successful with this approach is because they are a relatively small country and they tend to source locally. One of the reasons the U.S. struggles to implement JIT is that the country is much larger, and American companies tend to source globally and regionally. Simply put, suppliers are further away. A JIT strategy is dependent upon standardized work processes and methods that are consistently performed.
Variability is the enemy of Just in Time. Clearly this is an area where Lean and Six Sigma work together to drive out both variability and non-value added activities. As I point out here, there are lots of interconnections in using these tools For example, standardized processes support Just in Time practices. As a Lean project manager, you must have a strong understanding of each tool and how it can be effectively applied to improving your process.
Steven outlines the process stages in Six Sigma (define, measure, analyze, improve, and control), along with the Lean toolkit: the 5s principles, kanban (scheduling), downtime, poka-yoke (error proofing), and kaizen (continuous improvement). He also explains how leadership works within Lean Six Sigma, the principles of project execution, and how Lean Six Sigma is applied to the service sector and supply chain management. Make sure to watch the "Next steps" video at the end of the course for further resources.
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- Why Lean Six Sigma?
- Understanding the five steps of Six Sigma
- Understanding the 5 Ss of Lean
- Leading a Lean Six Sigma project
- Controlling a Lean Six Sigma project
- Using Lean Six Sigma for services and supply chain management