Fundamentals of Lean Six Sigma: Can Lean and Six Sigma Co-exist?

In an earlier post, I asked the question:

• How can Lean and The Theory of Constraints work together?

In my attempt to answer that question, I proceeded to describe the fundamentals of the Theory of Constraints.  In this article, I’ll do my best to explain the fundamentals of Lean Six Sigma (also known as Lean Management, Lean Enterprise, Toyota Production System, and Lean Manufacturing).

The Two Pillars of Lean Manufacturing

There are two pillars in Lean Thinking,

1. Respect for People
2. Continuous Improvement

Most consultancies, superficial practitioners, and most literature focus only on the tools under the Continuous Improvement pillar of Lean.  This is a mistake and many miss, mischaracterize, and fail to understand the spirit of how things are done with a Lean Thinking mindset or worldview.

One more important point before I move on:

everything we understand as Lean practices, principles, or tools come from either the Respect for People pillar or the Continuous Improvement pillar.

Respect for People

During my time at Toyota, the more common term was “Respect for the Human”, which carries a subtle difference.

Human, as opposed to People, carries with it an acknowledgement that, while we are all different, we all share very important characteristics:

• we all have thoughts, feelings, dreams, capabilities, gifts, and unique talents
• while we are all individuals, we are members of a community, country, all with their unique cultures and traditions; and we are all residents of the planet earth
• since we live on the earth, we must treat her well also

This basic mindset is a thread throughout how one carries-out Lean principles in an organization. The how is just as important as the what, but most forget this subtle but simple fact.

Here’s one example:

From my understanding, Kaizen actually comes from the Respect for People pillar.  Many make the mistake that it is purely a continuous improvement thing.  Kaizen is both a mindset and a method, but the bottom-line principle is this:

People have much to contribute.  We must develop our people, listen to them, and allow them to apply the principles of Lean to better their work area and the organization.  And, in doing so, people are growing, learning, and are happy.

Kaizen is much more about the development of the human than it is about changing the company for the better.  It’s about changing the human for the better first; then, it’s about changing the company for the better second.

Continuous Improvement

Most are familiar with the pillar of Continuous Improvement and the tools made famous by books on Lean and Toyota and made infamous by superficial lean consultants; tools like Kanban, Andon, Supermarkets, Takt Time, etc.

To better describe the pillar of Continuous Improvement, let me turn to Womack and Jones’ watershed work, entitled The Machine that Changed the World.

Specify Value

Value is defined by the customer.  And, the customer can be the end customer as well as the downstream process.

Value, can also be understood in terms of a question:

• If the customer were observing your process, product, or service: what would they have you continue doing?

The converse of that question and it’s response defines muda, or waste:

• If the customer were observing your process, product, or service: what would they have you stop doing?

Identify the Value Stream

In general, activities can be described as the following:

1. Value-added: This step in the process adds form, function, and value to the end product and for the customer.
2. Non-Value-Added: This step does not add form, function, or assist in the finished goods manufacturing of the product.
3. Non-Value-Added-But-Necessary: This step does not add value, but is a necessary step in the final value-added product.

(2) & (3) naturally create waste, of which there are 7 types:

• Over-Production: Producing more than is needed, faster than needed or before needed.
• Wait-time: Idle time that occurs when co-dependent events are not synchronized.
• Transportation: Any material movement that does not directly support immediate production.
• Processing: Redundant effort (production or communication) which adds no value to a product or service.
• Inventory: Any supply in excess of process or demand requirements.
• Motion: Any movement of people which does not contribute added value to the product or service.
• Defect: Repair or rework of a product or service to fulfill customer requirements.

Lean is difficult to describe.  The understanding comes from the doing. Codifying Lean Management in words is not easy; it’s easier to show you Lean than to describe it. But, despite the limitation of language, what I present here is my attempt at describing Lean.

In sum, Lean is about the complete elimination of waste; how Lean is carried-out requires that we do in the spirit of Respect for People.

In Conclusion

This is my attempt at describing the fundamentals of Lean Management.  As always, I have blind spots and ask of you, the reader, to help me with any important points that I’m sure I’ve missed.

In the next post, I’ll make an attempt at showing and reconciling how Lean Thinking and The Theory of Constraints can work harmoniously together.