6 lean manufacturing principles

Most manufacturing companies will waste a large amount of resources in a single year -- sometimes as much as 90%. Following lean manufacturing principles, which originated from the Toyota Production System, is one way for businesses to eliminate these costs using continuous improvement tools designed to identify and eliminate waste.

According to a U.S. Bureau of Census survey of 30,000 manufacturing facilities, the more lean manufacturing tools a company adopted, the faster it grew, and the more profitable and innovative it became. For U.S. automakers, lean is also credited with raising the time line-workers spend doing value-added tasks to over 90% -- compared to only 15-30% in the 1970's. The investment in lean is clearly worth the effort.

By identifying what does not add value to the customer, or what is wasteful, a company can begin to streamline it’s processes to operate more effectively. This can create improvements in productivity, material costs, and scrap. The following six lean manufacturing principles guide the process:

1. Map the value stream

Production processes, material information, and work flows should be diagrammed to determine the current state of operations. This allows lean managers to identify inefficiencies and where improvements can be made, as well as giving them a better understanding of the operation.

2. Flow processes

Lean manufacturers need to create flow among their processes. Materials, information, and workers should all move through the production process smoothly. This may require moving from silos to a cross-functional approach across departments and processes. While this can be a large undertaking, studies have shown focusing on flow improvements can lead to a minimum of a 50% improvement in efficiency.

3. Make what is necessary

Just-in-time (JIT) manufacturing is a principle of lean. Most lean facilities employ a pull system, in which customers’ orders signal both the supply and production schedules. Manufacturing occurs when it is dictated, as customers pull the product when it is needed. Products are not built in advance, so inventory levels are not in excess, which saves money for the manufacturer.

4. Reduce waste

The correct use of lean tools and techniques will allow you to find waste everywhere in the manufacturing environment. The seven wastes as defined by Toyota can be found in transportation, inventory, motion, waiting, overproduction, over-processing, and defects. Some lean practitioners also add underutilized employees to this list. By reducing yield loss due to defects or operator error, overall profitability will increase.

5. Ask employees

Lean manufacturers give their employees a voice in making the company more efficient. Employees are encouraged to report waste, making them active participants in the lean process. Let them lead lean training sessions and ask for feedback afterward. The more involved employees are, the better the outcome.

6. Continuous improvement

Adopting lean principles is not a one-time or static project. Continuous improvement is one of the most fundamental lean principles. Lean manufacturers analyze and evaluate to continuously cut waste and create value.

Why use lean?

Lean principles that are aligned throughout the supply chain can help a company overcome difficult economic periods and create a competitive advantage. Lean manufacturing can improve material handling, inventory, and quality, leading to a better product being delivered to the customer. A manufacturing company that employs lean principles will gain a competitive edge in the market.