My first interaction with Lean Manufacturing in real life was during my internship last summer, working at the Chrysler LLC, with the assembly line planning team. I was introduced to a new concept called World Class Manufacturing, WCM in short. Fiat and Chrysler CEO, Sergio Marchionne, emphasized WCM as “Chrysler’s Universal Language” and thus earning him the prestigious award of Michigan Manufacturer of the Year, among the competitors such as General Motors and Ford. You can listen to Marchionne’s interview on npr from January 18, 2013 talking about the last three years of Chrysler company and also around 02:45 you can hear Mr. Marchionne talk about how they have taken Toyota’s manufacturing system to a new level in the link below:
But what is this Toyota manufacturing concept that could revive a dying giant and make them the most successful American auto manufacturer? It is a story of family values building up to a manufacturing culture.
Lean manufacturing, pull, Kanban, Kaizen, Jidoka, Just in Time… Those are some of the terms that Toyota influenced or introduced to the manufacturing world and proved that a well-organized, constantly developing manufacturing can greatly impact the balances in international markets. With a strong desire for improvement, Toyoda family rooted all of its manufacturing to the idea of non-stop, constant development, widely known as “fix what is NOT broken”
As a young entrepreneur, Kiichiro Toyoda not only found today’s Toyota Motor Corporation, but also introduced a new, dynamic culture to the world’s manufacturing scene. His manufacturing strategies had shaped today’s field of industrial engineering. In order to understand this culture of Toyoda family, it would be appropriate to take a look at Sakichi Toyoda, father of Kiichiro San.
Inspired by his mother’s hand looming process, Sakichi Toyoda invented an automatic weaving machine. From an improved hand loom to power looms, Toyoda family achieved a breakthrough in history for automating the weaving process. With the growth, Kiichiro San began his research on small gasoline-powered engine. In 1937 Toyota Motor Co., Ltd. was established. Their most valuable asset and core competence have always been their family value of constant improvement.
Thus, when Kiichiro San decided to mass produce their Model-G Loom Machine under the company name, Toyota Automatic Loom Works, he implemented the American assembly line methods and refined the methods of American mass production to established the famous just in time method, which allowed only to “make what is needed, when its needed and only at the amount needed”.
In manufacturing, each process consists of three types of activities; value added, non-value added and necessary non-value added activities. Value added activities are the ones that add a value to the final product and thus costumer is willing to pay for, such as the operation of plastic injection machine. Non-value added activities are wastes that need to be eliminated, such as revision or recounting of a container. Non-value added but necessary items are sort of wastes that can be minimized or automated to reduce the costs. An example would be the time and effort spent in changing a drill’s tip to produce another part.
One of the biggest mistakes many companies make is to implement a game plan solely based on the idea of saving money by cutting “extra” costs to maximize profits. Even today, many manufacturing companies neglect the opportunity to optimize and improve and certainly don’t appeal to “fix things that are not broken” For example, in Toyota’s manufacturing, operator plays a significant role. Toyota not only acknowledges that the operator, who works everyday doing the same task over and over again, knows the best practice but also includes the operator into the equation of improvement.
Here are some of the most important lean manufacturing concepts briefly explained:
Kaizen, Japanese for “improvement” or “change for improvement” is the solid example of Toyota’s constant development culture and a symbol for their success. It allows processes that are functioning to be examined and improved. Kaizen takes into consideration of the operator’s suggestions for the process development. On a larger scope, Kaizen is used for balancing throughput, reducing changeover times and implementing a better practice of the procedure to convert as many wastes to value added practices.
Push vs. Pull
Also known as Ford’s manufacturing principle that had been the backbone of American manufacturing, Push system is highly dependent on the in-advance production planning. It follows a bottom-up fashion of manufacturing, where each operation is scheduled by the use of MRP (Manufacturing resource planning), however, takes away the flexibility in production, creating inventory and thus waste.
For the pull production, on the other hand, a single point is given a production order on the basis of daily consumer need. This process, in return, will trigger the preceding operations for production and thus a top-down production order is conducted between processes, by the use of Kanban cards.
Kanban serves as both a visual aid to signal production and production/withdrawal permission between processes. In the figure below, when distribution consumes a box, it sends the Kanban to manufacturing. Upon receiving the Kanban, manufacturing replenishes the supply for distribution. This minimizes the work-in-progress inventory and production is at pace with the customer demand. This allows the manufacturer to have accurate lead times, reduce wastes and have the flexibility to meet multiple consumer demand in a single shift.