Lean Manufacturing and Six Sigma are wildly popular continuous improvement methodologies, utilized by thousands of corporations today.

Some companies decide to implement lean manufacturing, while others believe six sigma is the necessary initiative to improve their business. There is now a growing list of companies combining both methods under the initiative called Lean Six Sigma. It is a fairly new approach, leaving many companies perplexed with the roadmap to implementation. It’s not surprising, since implementing either lean manufacturing or six sigma alone is a daunting task.

Lean manufacturing consists of about 25 major concepts, such as 5s, SMED, Error Proofing, Quality at the Source, Line Balancing, OEE, Kanban, Value Stream Mapping, Cellular Manufacturing, and Standard Operations. Some companies spend a few years implementing these terrific principles into their organization. Six sigma consists of a 5 phase methodology Define-Measure-Analyze-Improve-Control (DMAIC), utilizing hundreds of tools throughout the phases.

Combine both methods and all of these tools, and it’s easy to understand why initiatives fail. Unless the organization has the expertise to handle the implementation and help focus the efforts, the program becomes a shotgun approach and is doomed to fail. Most organizations could not withstand the chaos and prolonged costs without substantial payback.

Both lean manufacturing and six sigma principles are proven to work. Many companies have increased business, reduced costs, increased throughput, and lowered cycle times using both approaches. It only makes sense to utilize every tool available to obtain the maximum improvement possible.

It is critical for companies to let the problem determine the tools that are needed, rather than determine the tool and try and force the use of it. Some projects are obviously a lean manufacturing initiative. For example, if a machine has a 40 minute setup time and it is the bottleneck, then a SMED project is necessary. It may be part of a kaizen blitz or a simple SMED (single minute exchange of die).

There are clearly other projects which will be primarily a six sigma project. For example, a batch process plant using 12 different ingredients with various processes at different temperatures, speeds, and viscosities, would require a six sigma project to determine the best combination of machines, speeds, and viscosities to obtain maximum results. Some of the six sigma tools used would be statistical analysis, hypothesis testing, design of experiments, and analysis of variance (ANOVA).

There are many other types of projects where both lean manufacturing and six sigma tools would best solve the challenge. For example, suppose a batch processing problem involved the various ingredients, speeds, and temperatures. The best method might be a certain mix of machines, but the best one has a 5 person crew with a 2 hour setup time. It is time for the lean tools to reduce the cost per man hour utilizing OEE (Overall Equipment Effectiveness) tools as well as SMED, and possibly 5S.

A common use of lean tools in a six sigma project is during the Improve phase. The six sigma project Define, Measured, and Analyzed the problem, but a lean tool is necessary to solve it. Another six sigma tool will help Control it. If the company only used one of either six sigma or lean manufacturing tools, the problem may not get solved.

The beauty of six sigma is the methodical approach to opportunities. The advantage of lean manufacturing tools is the speed of implementation. When both tools are combined and used when necessary to solve business opportunities, the best result and greatest payback will be obtained.

Lean manufacturing is one of the most widely utilized business improvement methodologies. There are hundreds of consultants and schools teaching lean manufacturing principles.

The problem with many courses teaching lean manufacturing is the lack of real world experience of the instructor. Many have limited experience applying the principles, nor the interpersonal skills to influence change.

Lean manufacturing is not nearly as structured as six sigma or other continuous improvement initiatives. There is no standard approach to implementation or third party certifying body such as ISO.

Lean manufacturing consists of many different “tools”. The best courses teach the lean manufacturing principles as well as how and when to use the tools.

Some companies have heard that lean manufacturing implementation will reduce their waste and costs, and decide to just start implementing. They often start using one tool at a time until the boss declares it’s done.

Worse yet, some companies find a consultant that knows 5S and little else. When the consultant leaves, the clean and organized business eventually realizes they are clean, organized, and still full of waste.

The correct approach to implementing lean manufacturing begins with an analysis of the businesses needs, opportunities, and challenges. Once these opportunities are identified, the tools are used which will solve the issues. These tools might be lean manufacturing or six sigma tools. It simply wouldn’t be prudent to limit the success of a lean initiative to exclude any tool if it was known to solve the problem at hand.

In other words, the problems identify the tools rather than the tools being force into the organization.

Some of the lean manufacturing tools are 5S (Sort-Set in Order-Shine-Standardize-Sustain), value stream mapping, kanban, takt time, continuous flow, cellular manufacturing, TPM (total productive maintenance), SMED (single minute exchange of die), OEE (overall equipment effectiveness), line balancing, standardized operations,
7 wastes (muda), error proofing, kaizen, and root cause problem solving.

There are a few tools that can and should be used with any lean manufacturing initiative. The 5S tool is a powerful workplace organization tool. This tool makes sense in any business. It would be hard to find an organization where order and organization didn’t make sense.

Root cause problem solving tools should be used in every lean manufacturing implementation. These tools vary based on the problem. Some of the more common are Cause and Effects Analysis, 5 Why Analysis, 8D method, CT trees, Process Mapping, and affinity diagrams.

Value stream mapping is another useful tool to determine where value is added and the areas of non-value added (muda). The value stream map depicts the flow of product and information on paper. Information such as inventory, distance, and bottlenecks are highlighted. Once the value stream map is completed, opportunities for improvement become obvious.

Tools such as line balancing, SMED, takt time, and OEE should be used to solve specific business opportunities. For example, SMED (single minute exchange of die) is a tool that is used to reduce machinery or process setup times. This tool is a lot more useful in businesses that run smaller order quantities and changeover often. OEE is an excellent tool to determine why a machine or process is not producing at world class levels. Once the reasons (opportunities) are known, they can be improved.

Kaizen (Japanese word meaning continuous improvement) is a very powerful improvement tool. It is basically a rapid (3-5 days) improvement method utilizing a cross-functional team to solve a business problem. A kaizen event team will use many other lean tools to help solve the problem.

Total Productive Maintenance (TPM) is an excellent tool to improve maintenance, which in turn helps improve all aspects of a manufacturing business, including OEE, setup times, downtime, costs, and profitability. TPM is based on having operators involved in the maintenance of their equipment. The operators often complete their own preventive maintenance, while other initiatives simply have them highly involved. Although TPM is a great tool, it wouldn't be as useful in a service organization without equipment.

Utilize lean manufacturing principles to identify and solve business issues and the financial impact will justify their use. If the tools are made to “fit” the organization, the result will be chaos, disruption, low morale, and financial loss.

Almost everyone in manufacturing has heard about lean manufacturing. Most large corporations are in various stages of implementation. Many companies are currently applying the principles and building a lean foundation. Others are sustaining the implementation and continuously improving on the foundation. There are also many corporations wondering what went wrong or why they haven’t obtained the results they desired.

The primary key for success in lean is to understand that it is a journey. There is no “silver bullet” in any manufacturing or service industry. If there were, it would be sold and every company would have it.

Lean begins with the top management of the enterprise. Top management must have the vision to understand both the requirements and expected results, and commit the resources to achieving them. If the expected requirements and resources do not match, any system such as lean manufacturing will fail.

The requirements depend on the business. If the business has 5000 employees spread across 15 facilities in 20 different states, the requirements will be large. A small facility with 100 employees will require less.

Management needs to understand that lean manufacturing is a journey. It is a system of applied principles that leads the enterprise to a state of “lean”. If management is expecting to achieve “headcount reduction”, they are choosing the wrong system. Any headcount reduction should take place prior to implementing lean manufacturing.

Lean systems involve everyone in the enterprise to work diligently to remove all muda (waste) in the system. There are eight common types of waste defined in lean manufacturing. These wastes are so pervasive in organizations that everyone must pursue and eliminate them. People simply are not going to work themselves out of a job, and therefore everyone must be supportive of the journey.

Lean also involves continuous improvement through “kaizen”. Kaizen in Japanese means “small incremental improvement”. Kaizens involve employees from all functions to work together to eliminate waste, improve productivity, and improve the business in all aspects. Again, management must have employees empowered to improve the operation.

One piece flow is another system utilized in lean manufacturing. Therefore SMED (single minute exchange of die) systems to reduce changeover times must be employed.

Other lean concepts utilized in the journey include “pull systems”, “cellular manufacturing”, “kanban”, OEE (overall equipment effectiveness), TPM (total productive maintenance), error proofing, root cause elimination, and many others.

All of these systems require the effort of a large mass of employees to be successful. Therefore, employees must not be fearful of losing a job or lean manufacturing will not succeed.

Once employees feel they can trust management, the lean journey can begin. The journey begins with lean manufacturing training and it never stops.

Lean manufacturing is not a system that can be administered or implemented by a few individuals. It can be led by a few individuals, but the implementation will involve everyone.

Every person in the organization should first understand why the company is implementing lean manufacturing. Is it to have a competitive advantage? Is it to stay in business?

Since employees have always thought of management as “cost cutters”, it should be explained that costs are expected to come down in the long run. It should be explained why that is necessary, and what it will mean for the business. Lower costs enable the company to sell product or service. It might preserve existing jobs and lead to more hiring.

Once the overall goals of the company are explained, training should begin with the basics.

This will include an overview of lean manufacturing, 5S, 8 wastes (muda), problem solving techniques, and simple value stream mapping.

After initial training, individual concepts should be explained which apply to the company. For example, companies with machinery will be implement SMED, kanban, OEE, and TPM. Companies carrying inventory will want all employees to understand the waste involved in it.

Almost every company will begin with some type of “review” process. This review process will provide the “gap” analysis between where the company is in terms of lean versus where it wants to be. For example, setup times might average 12 minutes but need to be done in 3. Or cycle time might be 18 hours and it should be 6.

Once the analysis is completed, the training and implementation begins. Most companies begin training with 5S (workplace organization). Most implementations also begin with 5S while value stream mapping is often done simultaneously. As with all lean concepts, 5S, value stream mapping, and the review process never end.

Once these are implemented, the journey begins. Lean concepts are the arsenal to move the company to a state of lean. The lean leader utilizes the tools necessary to improve each part of the organization. Most often, many of the tools are utilized in every area.

When implemented correctly, lean is contagious. People in all functions from the plant or office floor to the executive suite are constantly looking for waste and non value adding activities. When they find them, they do everything possible to eliminate it forever.

Today, there are many consulting firms which help companies incorporate the lean process into their manufacturing processes. The consultants lead, instruct, and jump-start companies in becoming lean in their manufacturing, product development, and supplier relation activities.

Consultants work with you in developing your lean strategy, prioritizing the needed changes, and implementing them to the point of self-sustaining continuous improvement.

The first phase in lean methodology begins by drawing a clear picture of how your business creates its products. Consultants assess the current practices to identify specific gaps between existing operations and truly lean ones. This review includes scheduling, inventory management, customer service, communications and quality, by interviewing key personnel, reviewing procedures, and observing all processes that take place in your organization.

The second phase detects avoidable costs by identifying wasted materials and work tasks through Overall Equipment Effectiveness (OEE) studies, reducing setup times, and implementing 5S methods.

The third phase involves diminution of variability through enhanced flow and quality by focusing on efficient operations and minimizing error. This process includes optimizing the pace of work, point-of-use fabrication, total productive maintenance practices, poke-yoke, and use of various statistical lean tools.

In the fourth phase, a demand-based pull system is calculated and executed to reduce overall inventory, order turnaround time, and works in progress. "Just In Time" and "Kanban" techniques are also introduced to improve lead time and reduce inventories.

The final phase focuses on Process Control - the founding of an ongoing continuous improvement procedure. The consultants also provide complete on-site training for all stakeholders, including the use of simulations and creating infrastructure which will help the organization achieve Operations Excellence.

Ultimately, the consultants will instill a culture of continuous improvement into your organization and create key performance indicators that management can use to fine-tune their overall performance.

A lean manufacturing system is a system that meets high throughput or service demands with very little inventory. The lean manufacturing system contains several important principles as well as a collection of tactical methods for achieving them. The key principles of lean manufacturing are discussed below.

Value Streams: Let customers pull value through the enterprise by understanding what they want and then produce to meet real demand.

Stretch for Perfection: Pursue perfection by continually identifying and eliminating non-value-added activities from all processes.

Employee contribution: Involve employees in continual improvement and problem-solving activities.

Quick Implementation: Implement a rapid plan-do-check-act improvement framework to achieve results fast.

Performance Measurement: Use metrics and rapid performance feedback to improve real-time decision-making and problem-solving.

Organizational Approach: Approach improvement activities from a whole enterprise or system perspective.

There are several lean manufacturing systems (software solutions), which are primarily based on the above principles. Some of these are standardized for a wide range of operations and end-products while others are customizable as per specific requirements.

One of the modules used in such systems is the factory designer, which analyzes process throughput, defines mixed-model product families, calculates process time, documents standard work instructions, defines and balances operations, determines resource requirements and simulates factory designs.

Another module is a Kanban Management System (KMS), which supports the design and management of a Kanban system for a lean facility. KMS calculates the quantities and provides an effective method of maintaining quantities and containers as business variables change. Yet another module is a resource planning system to validate the daily production plan. This module allows lean production managers to calculate necessary staffing to meet the daily production schedule and to optimize productivity by re-assigning resources to constraints.

Thus, lean manufacturing systems prove to be good investments, not just automating but also for properly implementing the lean manufacturing initiatives.