Toyota Production System (TPS).
Toyota Motor Corporation's vehicle production system is a way of "making things" that is sometimes referred to as a "lean manufacturing system" or a "Just-in-Time (JIT) system," and has come to be well known and studied worldwide.
TPS Concept.
- JIDOKA (Highlighting / Visualization of Problem).
If a defective part or equipment malfunction is discovered, the machine concerned automatically stops, and operators stop work and correct the problem.
For the Just-in-Time system to function, all of the parts that are made and supplied must meet predetermined quality standards. This is achieved through jidoka.
Jidoka means that a machine safely stops when the normal processing is completed. It also means that, should a quality or equipment problem arise, the machine detects the problem on its own and stop, preventing defective products from being produced. As a result, only products satisfying the quality standards will be passed on to the next processes on the production line.
Since a machine automatically stops when processing is completed or when a problem arises and is communicated via the "andon (problem display board)," operators can confidently continue performing work at another machine, as well as easily identify the problem cause and prevent its recurrence. This means that each operator can be in charge of many machines, resulting in higher productivity, while the continuous improvements lead to greater processing capacity.
- JUST IN TIME (Productivity Improvement).
Making only "what is needed, when it is needed, and in the amount needed!"
Producing quality products efficiently through the complete elimination of waste, inconsistencies, and unreasonable requirements on the production line.
In order to deliver a vehicle ordered by a customer as quickly as possible, the vehicle is efficiently built within the shortest possible period by adhering to the following:
When a vehicle order is received, a production instruction must be issued to the beginning of the vehicle production line as soon as possible.
The assembly line must be stocked with small numbers of all types of parts so that any kind of vehicle ordered can be assembled.
The assembly line must replace the parts used by retrieving the same number of parts from the parts-producing process (the preceding process)
The preceding process must be stocked with small numbers of all types of parts and produce only the numbers of parts that were retrieved by an operator from the next process.
Roots of Toyota Production System
The Toyota Production System, which is steeped in the philosophy of the complete elimination of all waste and imbues all aspects of production with this philosophy in pursuit of the most efficient production method, traces its roots to Sakichi Toyoda's automatic loom. The TPS has evolved through many years of trial and error to improve efficiency based on the Just-in-Time concept developed by Kiichiro Toyoda, the founder (and second president) of Toyota Motor Corporation.
Central to the TPS is the philosophy of "the complete elimination of all waste."
Waste can manifest as inventory in some cases, processing steps in other cases, and defective products in yet other cases. All these "waste" elements intertwine with each other to create more waste, eventually impacting the management of the corporation itself.
The automatic loom invented by Sakichi Toyoda not only automated work that used to be performed manually but also built the capability to make judgments into the machine itself.
By eliminating both defective products and the associated wasteful practices, Sakichi succeeded in tremendously improving both productivity and work efficiency.
Kiichiro Toyoda, who inherited this philosophy, set out to realize his belief that "the ideal conditions for making things are created when machines, facilities, and people work together to add value without generating any waste." He conceived methodologies and techniques for eliminating waste between operations, between lines, and between processes. The result was the so-called Just-in-Time method.
By practicing the philosophies of "Daily improvements" and "Good thinking, Good products, " the TPS has evolved into a world-renowned production system. Furthermore, all Toyota production divisions are making improvements to the TPS day and night to ensure its continued evolution
Nowadays, the "Toyota spirit of making things" is referred to as the "Toyota Way." It has been adopted, not only by companies inside Japan and within the automotive industry, but in production activities worldwide, and continues to evolve globally.
Kanban System
In the TPS, a unique production control method called the "kanban system" plays an important role. The kanban system has also been called the "Supermarket method" because the idea behind it was borrowed from supermarkets. Supermarkets and mass merchandizing stores use product control cards on which product-related information, such as product name, product code, and storage location, is entered. Because Toyota employed kanban signs in place of the cards for use in production processes, the method came to be called the "kanban system." At Toyota, when a process goes to the preceding process to retrieve parts, it uses a kanban to communicate what parts have been used.
Why use a supermarket concept?
A supermarket stocks the items needed by customers when they are needed in the quantity needed, and has all of these items available for sale at any time.
Taiichi Ohno (a former Toyota vice president), who promoted the idea of Just-in-Time, applied this concept, equating the supermarket and the customer with the preceding process and the next process, respectively. By having the next process (the customer) go to the preceding process (the supermarket) to retrieve the necessary parts when they are needed and in the amount needed, it was possible to improve upon the existing inefficient production system in which the preceding processes were making excess parts and delivering them to the next process.
The assembly line must be stocked with small numbers of all types of parts so that any kind of vehicle ordered can be assembled.
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Posted by haneyama
at 2:57 AM EDT
