Did you know that most lean manufacturing concepts were developed from the philosophies of Benjamin Franklin?
And Henry Ford cited Franklin as a major influence on his own business practices, which included Just-in-Time manufacturing.
Let’s take a look at some of the guiding principles for implementing a lean manufacturing protocol…
First and foremost is waste reduction/elimination. Historically, this is the foundation of modern-day lean manufacturing, identified by Toyota Production System in the 1990’s.
Many of the other principles revolve around this concept. There are seven basic types of waste in manufacturing:
- Overproduction (production ahead of demand)
- Unnecessary Motion (moving people or equipment more than is required to perform the task)
- Excess Inventory (all components and finished product not being processed)
- Production of Defects (leading to rework, salvage and scrap)
- Waiting (i.e., waiting for the next production step or interruptions of production during shift change)
- Transportation (moving products that are not actually required to perform the task)
- Overprocessing (resulting from unnecessary work that adds no value)
Waste reduction/elimination involves reviewing all areas of your organization, determining the source of all non-value-added work, and reducing or eliminating it.
Continuous improvement is sometimes referred to by the Japanese word “kaizen,” which literally means “change for the better.”
As the name implies, continuous improvement promotes constant, necessary change toward achievement of a desired state. The changes can be big or small, but they must lend themselves toward improvement.
To be effective, continuous improvement should be a mindset throughout the entire organization. Lean manufacturing experts suggest that you not get caught up in only trying to find the “big ideas,” as small ideas can often lead to big improvements.
For instance, at Toyota, the culture of continual aligned small improvements has yielded large results in overall improved productivity.
Respect for Humanity
The most valuable resource for any company is its people. Without them, the business simply will not succeed.
When employees do not feel respected, they tend to lose respect for their employer. This can become a major problem when a company is trying to implement lean manufacturing principles.
To achieve this, levelized production takes into consideration both forecast and history.
Your customer orders most likely fluctuate daily. Let’s say on Day 1, they want 10 black and five red parts. The next day, they want 12 red and seven black. On Day 3, they only require 13 parts.
Using levelized production:
- On Day 1 you would set the level volume at 15 parts per day, and production would replenish the 15 parts that were ordered.
- On the second day, the order is 19 parts (four parts higher than our levelized production volume). Production would still build 15 parts and the shipping area would take four parts from an inventory called “fluctuation stock.”
- On the third day, the order was 13 parts, which is two less than the levelized volume. So two parts are put back into fluctuation stock.
The basis behind just-in-time production is to build what is required, when it is required and in the quantity required. In conjunction with levelized production, this principle works well with the pull system. It allows for movement and production of parts only when required.
The goal in lean manufacturing is to maintain finished product inventory at the lowest levels possible, while ensuring delivery does not suffer. Of course, it is nearly impossible to carry zero inventory, particularly in facilities where short lead time is essential. So you will need to carry a store of parts to pull from when required.
To facilitate just-in-time production, companies typically employ a system of “kanbans.” A kanban is a hand-sized card that moves with the product or material. It signals when the product is to be built or when the material can be moved.
The kanban basically serves as a work order or pick list. But it also serves as a visual control, to identify the contents of each box. A third function of a kanban is inventory control, to determine the amount of finished product on hand.