From what I’ve written so far, you might
think that I have a negative view of Lean and Six Sigma, but such thinking is
far from the truth. In fact in many
cases, the Theory of Constraints cannot deliver sustainable bottom line improvement
by itself. The reality is, TOC does
provide the needed global system focus which is paramount to facilitating
organizational growth. As I said in one
of my earlier posts on this integration, the primary reason why Lean or Six
Sigma have failed to deliver acceptable ROI’s is they try to improve everything
all at once, rather than focusing on the most important leverage points. In my posting today, I will be repeating much
of what Bruce Nelson wrote in our book

*Epiphanized*(Appendix I) about the integration which is now popularly referred to as TLS. Some of the figures will be updated to reflect Bruce and my new way of presenting the concept of*focus*and*leverage*.
The foundational concepts of TOC can be
presented in a simple, but understandable way as a reference environment. If you understand the reference, you understand
the concept. If we use a diagram showing
a simple piping system with the primary goal of delivering water, then the
reference is defined. By presenting the
concept in this format, the basic principles will be much easier to comprehend
for people who have not yet had any experience with the Theory of Constraints.

The figure above describes the piping system
with different diameter pipes connected together supporting the water flowing
through this system. The water is gravity
fed and flows from top to bottom from Section A through the entire length of
the system until it exits at Section I.
If you were given this water system and asked what you would do to
increase the flow of water, or the throughput of water through this system, how
would you answer this question? For most
responders, the answer would be to increase the pipe diameter of Section E
since it is the choke point or bottleneck or constraint of this system. If you increased the diameter of any other
pipe section, it would have absolutely no effect on the throughput of water
through this system.

If you were asked how much you would increase
the diameter of Section E, how would you answer this question? Most responders would answer by saying that
the increased diameter of the Section E pipe would be determined by how much
more water the system needed to deliver (loads on the system). So in order to satisfy the need (demand) for
more water, you must have some type of metric for how much more water is needed
(increased loads on the system). Let’s
say that you increased the diameter of Section E to the same diameter of
Section B. What is the measured
throughput of water out of Section I was still not enough to satisfy the new
demand, what then? The new focus for
system improvement would shift to the new constraints (the constraints have
moved) which are now both Sections E and B.
These two sections become interactive with each other. The diameter of these two pipes now become
the new system constraint and they need to be improved to meet the increased
demand. So how does all this apply to
the real world?

The basic principles of understanding
constraints are all around us. For
example, instead of using the piping system to demonstrate the constraint, we
could have substituted an electric circuit with different sized resistors and
measured the flow of electricity through the circuit. The resistor location with the highest
resistance to electrical flow would be the equivalent of Section E in the
piping diagram. You could easily
demonstrate that the flow of electricity through that system is completely
dependent upon how much more electrical current was needed to satisfy
demand. And in order to increase the
electrical output, you need to reduce the resistance of the resistor that was
limiting the electrical flow.

The figure below is another simple visual
example of the same concept. Here we
have a four-step process used to produce some kind of process or service. If we apply the same

*systems thinking*and ask the same series of questions about the system, then we can effectively conclude that Step 2, at 17 days, is the process that is limiting the output from this system. By understanding this concept, you now know where to focus your improvement efforts. Improving any other process in this system, except for Step 2, yields no system improvements at all. Globally, the system will improve only when Step 2 requires less time.
With the foundational concepts of the three
improvement initiatives laid out and defined, where does this take us? If you apply the methods of TOC first ad use
TOC to analyze the system, and spend the necessary time to do it correctly,
then you can employ the other methods of Lean and Six Sigma to help exploit the
constraints. If the constraint quickly moves
to a new location, then go back to Goldratt’s Step 1 and start over. It is possible that the “fix and move” cycle
can repeat several times before the system is stabilized and requires the
implementation of Step 3, subordination.

If your current Lean or Six Sigma initiatives
are suffering from a lack of real bottom-line improvement, then what is being
presented here should be of interest to you.
Why? Because the biggest reason
many Lean or Six Sigma improvement initiatives fail to deliver sustainable
bottom line improvement is that they are primarily focused on the wrong
improvement point. The mistaken
assumption is, if you improve everything, then hopefully you will achieve the
benefit of something. This notion of
improving something in hopes of saving a few dollars should be abandoned as
wasteful. There is a better way. The necessary condition is that you take the
time to understand what the problem really is.
If you don’t understand and focus on the real problem, it will be
impossible to come up with the correct

*leverage*to implement a solid solution. Take the time to slow down your thinking and understand precisely where to focus your improvements. If you think in terms of TLS (that is, the combination of TOC, Lean and Six Sigma), your results will be much more gratifying.
Think for a moment, imagine what would happen
using the focusing power of the Theory of Constraints coupled with the
improvement potential of both Lean and Six Sigma. The crucial component to real bottom-line
improvement is to increase the throughput through the systems. Remember, throughput is not the same as
output. Throughput only materializes
when the sale occurs and fresh money is received from the customer and put back
into your system. So by identifying and
focusing the full improvement potential of Theory of Constraints, Lean and Six
Sigma on the global system, it is possible to increase throughput…..perhaps
exponentially!

Bob Sproull

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