The Basics of Lean Manufacturing and Six Sigma
Lean manufacturing and six sigma are not new concepts to business practices. In fact, lean manufacturing was implemented by Toyota back in the 80’s after they had studied the difference between U.S and European manufactures. From their studies, lean manufacturing was born and the way of focusing on eliminating waste and lead time was created. Six sigma was created by Motorola in 1986. The original intent was to improve the quality of process in its manufacturing operations, but now the process has been reiterated in all forms of business operations. There is a lot of information on these processes and even a certificate program for the six sigma process. Below is the breakdown of each process:
Six sigma uses two different sets of methodologies DMAIC and DMADV. Each one targeting a different area of the operations process.
Define – The objective is to outline the borders of the project. This can include the customer and their expectations, the impacted business processes, scope and budgetary items, team development, ect.
Measure – The objective is collect data and use metrics to track effectiveness.
Analyze – The objective is to discover the root cause of the businesses inefficiencies using the data you had previously collected. From the data you will be able to identify holes between current and desired performance.
Improve – The objective is to be able to implement a new process companywide that has been tested out.
Control – The objective is to develop procedures regarding the new process, control plans and train the staff.
DMAIC focuses on the manufacturing or production side of a product or service, while DMADV focuses on examining and improving the customer relations side of a company.
Define – The leaders identify wants and needs that are most important to customers. The information for customers wants and needs are found in historical information, customer feedback, ect.
Measure – Using data collection software measure customer needs, reviews of products and/or service.
Analyze – With the data collected evaluate areas that need to be improved to meet customer expectations.
Design – Combine the new process that was created from DMAIC and align it with a way to also meet customer needs.
Verify – Create a process that continually tests and checks that customer needs are being met on an ongoing basis.
Six sigma is derived from the statistical principle that “if you start at your process’ mean value and you eliminate defects within six standard deviations of the mean and the nearest specification limit, you’ll virtually eliminate all defects or errors.” (thebalance.com). The process of Six Sigma has a hierarchy to determine a person’s expertise in the methodologies:
Green belt – The initial level, a person with this training implements Six Sigma into their primary job duties are guided by black belts.
Black belt – Takes a month or more of training and requires completion of a Six Sigma project. This person dedicates their professional life to Six Sigma working under the Master Black Belt.
Master Black Belt – While being a mentor to green belts and black belts, the master black belt also monitors and makes sure the Six Sigma projects are maintained.
Six Sigma Champions – This is a person chosen by Executive Leadership. Their responsibility is to push for Six Sigma project and guarantee it’s resourced and on track.
Executive Leadership – The top of the hierarchy, this person determines the strategy for the Six Sigma implementation and set the borders and duties of each person on the project.
Toyota created lean manufacturing to eliminate waste and lead time. Here are the seven core areas to concentrate on:
- Inventory – a company should watch the volume of inventory they have in place as inventory is considered to be waste and should be minimal.
- Waiting Time – This applies to employees waiting for their task as they have to wait on a machine or someone else to finish their task before they can begin theirs.
- Motion – This refers to the amount of time employees spend walking from one section of the production line to the next.
- Transportation – This is the time spent moving materials and products around the warehouse or from location to location.
- Over-processing – production processes often have processes that do not add value to the product which is wasteful. For example, adding too many steps in an inspection.
- Over–production – creating more than needed, earlier than needed.
These are the top categories Toyota came up with. As companies have adopted this principle they have added or removed some categories fitting what is considered waste to match their company. Toyota also came up with four rules when implementing the lean manufacturing principle. These rules taken from TXM Lean Solutions are:
- All work is specified in terms of content, sequence, timing and outcome
- Every customer-supplier connection must be direct and there must be an unambiguous yes or no way to send requests and receive responses in the supply chain
- The pathway for every product or service is simple and direct
- Improvements are made using a scientific method under the guidance of a teacher, at the lowest possible level of an organization