A Guide to Implementing the Theory of Constraints
Start By Stopping For A Moment
Slow down, block out
the rest of the world for a moment, and take the time to consider the
following. Have you ever found
yourself in a situation where you were waiting for someone to provide you
with something, something that you must work on, and in-turn, which you had to pass on to someone else? Someone else who may have also been waiting
for that particular piece of work? And
it wasn’t as though you had no other work – correct? In fact, it is most likely that you were up
to your eyeballs in work, other work – but not the work that you needed at
that moment. In fact its quite likely that you were continuing to receive work
that you didn’t particularly need or want at the moment, and you were passing
on work that others didn’t seem particularly enthused to receive, even if
they had been complaining about it only a few days previous. You probably wondered why you hurried.
I doubt that there
are very many who can’t relate to this.
In fact, for many of us, in our day-to-day working lives, it is the
rule rather than the exception. It doesn’t really
matter if you are on the shop floor or in corporate, manufacturing or
services, it pretty much seems universal.
Universal or not,
does it need to be like this?
I hope to show you
that, indeed, it does not need to be like this at all.
What this short
moment of reflection shows is that most of us already have a pretty good
intuition for the concepts of dependency, variation, and an understanding of
systems and therefore the necessary intuition to find the needed
solutions. And really that is all you
require to understand the Theory of Constraints.
Theory of Constraints
is the invention of Dr Eliyahu Goldratt, an Israeli physicist, educator, and
It’s a business
which seeks to strive towards the global objective, or goal, of a system
through an understanding of the underlying cause and effect dependency and
variation of the system in question.
It is equally
applicable to for-profit and not-for-profit organizations for; strategy, personnel,
marketing, sales, distribution, manufacturing, design, and project
This web site is
designed to be an introduction to some of the important concepts of the
Theory of Constraints and its successful implementation. It is biased a little toward the manufacturing
end of the spectrum. But if you run a
hospital for instance and can’t see the parallels, then please let me know.
It is likely that
you will have arrived at this material from a number of different directions;
that are already very successful (we aren’t making enough money).
that are not successful and in need of turnaround (we aren’t making any
ventures (we can’t achieve sufficient output with our current funding).
In each case we are making
insufficient of whatever it is that the organization needs to make in order
to be successful. In other words, we
are, in some way, constrained.
Although Theory of
Constraints developed out of for-profit based manufacturing, it has a much broader and more general
applicability. People in
not-for-profit organizations, or service organizations, or a paper-based
transaction will find the principles equally relevant and applicable.
Indeed you probably suffer from “flavor
of the month syndrome” – and we all do to some extent – then get your very
best “healthy skepticism hat” out and read on. But consider, also, that the very existence
of something called flavor of the month syndrome must demonstrate a deeper
and on-going need or a desire to improve something – our organizations – our
working lives. The problem seems to be
that we are constantly seeking something out, and constantly being forced to
abandon those methods that fail to deliver the results that we seek.
Equally, be aware
that it is almost 30 years since the beginnings of the solution to the problem
that has given rise to the concept of Theory of Constraints, and yet it is
still with us (1). And think of
just-in-time with its beginnings by Eiji Toyoda and Taiichi Ohno in the early 1950’s, and yet
it is still with us (2). What then of
statistical process control with an even deeper past extending back to Walter
Shewhart’s work in the 1920’s, and yet it too is still with us (3).
Why is it that
after 30, or 50, or 80 years, these 3 particular methodologies are still with
us, offering solutions that are just as valid today as they were at the time
of their inception? Think about it.
Why is this?
Well all of these approaches are systemic. Note the spelling; it’s not a mistake,
systemic rather than systematic. Certainly
these approaches are also systematic as well as we will shall see, however,
systemic approaches are concerned with the system as a whole, not with parts
of a system in isolation.
Think back for a
moment to the introduction when we imagined that we were stuck somewhere in a
process. Did the process look
something like this?
And where did you put
yourself? Probably somewhere in the
middle or near the end? That’s quite
interesting. I think most of us are
aware of an overall system or process, and yet we still break the system down
into local parts. Peter Senge wouldn’t
be surprised (4);
“From a very early
age, we are taught to break apart problems, to fragment the world. This apparently makes the complex tasks and
subjects more manageable, but we pay a hidden, enormous price. We can no longer see the consequences of
our actions; we lose our intrinsic sense of connection to the larger whole.”
So we do seem to
have an innate systemic understanding but we tend to still break things down
statistical process control, and Theory of Constraints are all system
approaches. Goldratt characterizes a
system approach as a warning against “concentrating on a local optima (in
place or time) and, by that, jeopardizing the performance of the system as a
statistical process control tells us that “as long as the deviation of a
process is within the statistical boundaries, the biggest mistake a person
can make is to re-align the process.
It is a warning against local optima in time; at this instant you may
think that you have brought the process to be closer to the average but
actually you enlarged the deviation of the system.” With regard to kanban in just-in-time “what
is it if not a technique that is built to prevent the local optima of a
worker producing all the time, producing even when down-stream operations do
not now need the results of his/her work?”
In Theory of
Constraints the key to not concentrating on local optima everywhere is
described by a special term – subordination.
We will return to subordination issues often.
We mentioned that
all of these methods were systematic as well as systemic. In order to be systematic we need a
focusing mechanism to guide us where to place our attention first, second,
and so forth. The focusing mechanism
and statistical process control is Pareto analysis; the focusing system for
Theory of Constraints is the 5 focusing steps which we will describe in full
in the page on process of change.
Each of these
methods while acknowledging
the overall system also acknowledges that within the system there is
dependency and variation. It is
acknowledgement of variation that sets these particular approaches far apart
from many other business approaches.
Have you ever seen a budget prepared with a target goal +/- some
variation for error? I don’t think
so. The variation is there without
doubt, but it is not acknowledged. And
if it is not acknowledged it can’t be managed. In fact, we manage to try and ignore it by
consistently estimating on the low side with lots of safety tucked away
everywhere. If we have lots of safety
tucked away everywhere then once and a while we should exceed our target goal
– ever wondered why that doesn’t seem to happen? It seems then that we never get to really
know our true potential.
Almost by default,
because we have defined a system with boundaries of some sort, we have also
defined that there must be finite capacity within that system. Usually defined by the slowest step in the
process in just-in-time and Theory of Constraints. It is sometimes useful to consider this
step as the weakest link in a chain.
And just as you can ignore the weakest link in a chain, but the weakest
link won’t ignore you, so too can you ignore the slowest step in a process but
the slowest step won’t ignore you. In
other words, regardless of what you do, the slowest step or weakest link will
determine the rate or strength of the whole system.
something manufacturing people do – right?
Well then consider this. Have
you ever heard someone say to you; “Well, we like your idea but we can’t
consider your proposal/request until next week when we usually consider
these?” Ah, that sounds like batching
to me, batching in time.
How about; “Yes,
we like your idea but we can’t process your application until we have a
sufficient number, please put it over there.”
Ah, that sounds like batching too, batching in quantity. You see we are all surrounded by batching
actions, some so common we hardly think about it at all. Is this important? Well I think so, especially if you consider
the comments about dependency and variation.
Batching increases the variation in the system and exacerbates the
Imagine you are a
downstream step from a batching operation of some sort. Maybe towards the end of the current batch
you are beginning to run out of work, you slow down, it’s important to keep
busy after all. But it’s also like the
calm before the storm; you know that when the next lot of work is released
then suddenly you will have a lot of work on your hands and you will have to
work quite quickly to move some of it through. So the work load is variable for no other
reason than we had to batch before your position in the process. Variation increases with batching.
The batching also
highlights dependency. You probably
had productive time towards the end of the last batch – that calm before the
storm – but you couldn’t use it. It
was lost to the system, and now that you are in the middle of the current
batch – up to your neck in work – you have no excess or spare capacity to
call upon to help you. If only you
could have somehow magically stored that capacity from the quiet period and
shipped it to the busy period when it would have been useful. So, batching also highlights dependency.
There are strong
parallels between the systemic approaches we have been talking about and the
concepts of detail and dynamic complexity of Senge.
In the Fifth Discipline he describes these
two types of complexity (4);
complexity – the sort where there are very many different variables to
complexity – the sort where cause and effect are subtle and the effect over time is not obvious.
In operating a
process, regardless of whether it is a small job shop or a huge factory, and
regardless of whether it contains highly variable human patients or uniform
mechanical parts, is full of detail complexity. However the underlying dynamics are limited in
variety and not particularly complex.
When someone tells
you that there are 17 different ways to grind a drill shank they are telling
you about detail complexity. When
someone tells you there are 3000 stock items, again they are telling you about detail
However, when an
action has different effects over the short run and the long run we are
really looking at dynamic complexity.
When an action has one set of consequences locally and a very
different set of consequences in another part of the system, then there is dynamic complexity. When obvious interventions produce
non-obvious consequences, there is dynamic complexity.
“The real leverage
in most management situations lies in understanding dynamic complexity, not
complexity (4).” Restated; the real
leverage in most management situations lies in understanding cause and effect
dependency and variation.
Let’s be clear
then, there is nothing wrong with detail complexity when it is applied to
various attributes of products in a process. In fact,
you already have the expertise to deal with this; otherwise you wouldn’t be
in business. The error, if you like,
is when we attempt to apply detail complexity to the process that produces
the products. This is the domain of
We can combine the
dynamic and detail complexity concepts of Senge with the global objective
versus local objective concepts of Goldratt in a simple 2 by 2 matrix. This is what we get.
This gives us two
diametrically opposed concepts. The
first is a combination of dynamic complexity and global optimization which we
will call the systemic/global optimum approach. The second is the combination of detail complexity
and local optimization which we will call the reductionist/local optima
approach. These are two key concepts
that underline much of the discussion and development in the following pages. Let’s list these for further clarity;
They represent two
different lenses through which we can view our organizations.
Let’s return to
Senge once more; “The most powerful learning comes from direct
experience. Indeed we learn eating,
crawling, walking, and communicating through direct trial and error – through
taking an action and seeing the consequences of that action; then taking a
different action. But what happens
when we can no longer observe the consequences of our actions? What happens if the primary consequences of
our actions are in the distant future or in a distant part of the larger
system within which we operate? We
each have a ‘learning horizon,’ a breadth of vision in time and space within
which we assess our effectiveness.
When our actions have consequences beyond our learning horizon, it
becomes impossible to learn from direct experience (4).”
“Herein lies the core learning dilemma that
confronts organizations: we learn best from experience but we never directly
experience the consequences of many of our most important decisions.”
What if there was
a simple way to verbalize and capture the cause and effect which we never directly experience, but
which we none-the-less have the intuition for? What if we could overcome this core
learning dilemma? Senge proposed
computer-based “microworlds,” but what if we could do it on the back of an
envelope – pen and paper? There is a
mechanism that allows us to verbalize, construct, analyze, and communicate
these cause and effect relationships, and moreover, to propose workable
solutions to the problems that they cause.
This is known as the Thinking Process.
Mention of the Thinking Process brings
us to the concept of elegance. In the
sciences the meaning of elegance is one of simplicity and ingeniousness. An elegant solution to a problem is a cause
for considerable respect. Theory of
Constraints seeks elegant solutions to problems, rather than sophisticated
ones. Elegant solutions are more
likely to have broken some deeper core or underlying problem; sophisticated
solutions are likely to have addressed a limited number of higher order
problems (symptoms) while leaving the underlying core problem unresolved.
The solutions may
be elegant, but they are also incredibly robust. This robustness means that doing something,
anything, which is aligned with the direction of the solution, is most likely
to bring about an improvement or movement towards that improvement. In contrast the surest way to fail is to
sit around measuring and data gathering and waiting until you are sure your
implementation will be perfect. It
won’t be perfect because it will never start.
Robust solutions can stand a lot of rough handling. The best thing to do then is to do
If a picture is
worth a 1000 words, then please accept the following as a visual summary.
Most of all,
Constraints is a work-in-progress. It
evolve into new areas as people discover its broader applicability and it
also continues to improve in delivery in established areas as people refine
Hopefully you have
been armed with some key concepts. We
want to improve systems. We need to recognize that
dependency, variation, and finite capacity exist in these systems. We need to understand that seemingly
complex cause and effect occurs via these dependencies, both in time and in
space, and this has been termed dynamic complexity. Understanding these features is the key to
gaining control and moving our system in the direction that we desire.
Let’s have look
then at the effect of this on the bottom line.
(1) McMullen, T.
B., (1998) Introduction to the Theory of Constraints (TOC) management
system. St. Lucie Press, pg 114.
(2) Ohno, T.,
(1978) Toyota production system: beyond large-scale production. English translation, Productivity Press, pp
(3) Lepore, D.,
and Cohen, O.,
(1999) Deming and Goldratt: the Theory of Constraints and The System of
Profound Knowledge. North River Press,
(4) Senge, P. M.,
(1990) The fifth discipline: the art & practice of the learning
organization. Random House, pp 3, 23,
(5) Goldratt, E.
M., In: Cox, J. F., and Spencer, M. S., (1998) The constraints management
handbook. St Lucie Press, pp ix-xi.
Copyright © 2003-2009 by Dr K. J. Youngman