A Guide to Implementing the Theory of
Constraints (TOC) |
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Good
Intentions Are Not Enough “It is said that the way
to hell is paved with good intentions.
Good intentions are not enough to solve the problems that arise among
people (1).” Takashi Kawase
a very successful and respected kaizen/JIT academic and consultant knows only
too well when he says that good intentions are not enough to solve the
problems that arise among people. In
this section we will limit ourselves to some Theory of Constraint specific
techniques that might help, in addition to good intentions, to align people
within a manufacturing implementation. Let’s break
this down into two parts. The first
dealing with the issues – conflicts – that arise out of detail complexity and
how to reframe these in a way that they can be solved. In the second part we will deal with the
issues – conflicts – that arise out of dynamic complexity and how they too
can be solved. Let’s return
to our departmentalized version of our system for a moment. The version that we previously drew for the
section on people.
We can write
this conflict as a “cloud”. A cloud is
a very useful graphical mechanism for breaking conflicts. A detailed description of clouds is given
in the thinking process section.
However we will use it here in advance. Let’ draw a
cloud for this particular problem.
The power of
the cloud comes from the belief that there are no conflicts in nature – only
erroneous assumptions (2). The
assumptions “hide” under each of the arrows in the diagram. Let’s draw
some of them in.
Let’s do that.
This is how
our diagram now looks.
Consider the
situation now where foreman A and foreman B are both a part of the same
supervisor’s area.
Let’s draw
that.
Dynamic
complexity issues must be framed in terms of the whole system if they are to
be satisfactorily resolved. And in our
reality there is likely to be an internal constraint or at least an internal
control point to consider. Let’s draw
that.
Let’s suppose
the conflict is something like this.
The
lieutenant’s cloud addresses the case were we want to do things that are
necessary for the success system but we are unable (3). This arises because the people concerned
have the responsibility for success but do not have the authority to carry
out the needed action. Cohen also
calls this a misalignment cloud or a firefighting cloud. The
construction and use of the lieutenant’s cloud is sufficiently important that
it is addressed on a separate page.
Please learn how to construct and use the lieutenants’ cloud and internalize the process. Think about it
for a moment; we already recognize and understand the focusing steps
“identify,” “elevate,” and “exploit.”
We know them well from the world of local efficiency and product
costing – the world of the reductionist/local optima viewpoint. But “subordination” is different. The concept of subordination doesn’t exist
in the reductionist/local optima world; it only exists in the world of the
systemic/global optimum viewpoint. We
especially examined this concept in a number of different places in the page
on process of change and again in the page on implementation details. Effective
subordination can be divided into two; (1) Doing things that are necessary for
the systems success. (2) Not doing things that are not necessary
for the systems success. Subordination
isn’t so much a problem of failing to do new things that are necessary,
because this requires some sort of positive action. Subordination is more a problem of failing
not to do things that are no longer necessary – especially no longer doing
old things, things we have always done; because this doesn’t seem like a
positive action any longer. Not doing
old things, things that were so common in the past that they have become
automatic, is a major cause of misalignment in TOC implementations. Whereas the
lieutenant’s cloud most often addresses making sure we can do something that
should be done, in many other instances we must also address not doing things
that don’t need to be done – in a way addressing inertia. In
drum-buffer-rope the number of things that we must control is substantially
reduced to those that are really important
– material release date, divergent/convergent control points, drum schedule,
and shipping/completion schedule. This
can be quite different from current mode of operations, especially if the
organization is using some variant of MRPII.
Thus the subordination conflict becomes; do something that is not new
and is required versus not doing something old and which is not
required any further. In other words;
don’t control everything, versus control everything. Let’s have a look at this.
In order to be
successful in our implementation we must protect the whole system, and in
order to protect the whole system we must not control everything. On the other hand, in order to have a
successful implementation we must protect each department in the system, and
in order to protect each department we must control everything. Hmm. There is a conflict between the desire to
control everything and the desire not to control everything. Because I
personally see many system-wide needs as “dynamic complexity” problems and
many departmental needs as “detail complexity” problems, I would like to also
frame this conflict in terms of detail
complexity and dynamic complexity
In the past
every time there was a problem, a new measurement would be introduced. Even when the problem went away, or even if
the problem wasn’t particular to that area it is likely that the measurement
is still in place. Inordinate amounts
of time are consumed by line management recording data and preparing reports
that are of little benefit, except that it gives a feeling of being in control
– and to protect line management from blame if something should go wrong
somewhere else. You will see
this cloud expressed again and again and again during an implementation. No one will say outright that they are
scared of losing control of their area or of their performance; you have to say
it for them. Once it has been
verbalized – brought out into the open, and acknowledged, then progress will
be made. Often, the
most effective way to break this cloud once it has been verbalized is ask for
a trial with a set time frame. People
who fear losing control of everything will welcome a trial to prove that
matters will only get worse (as they suspect), and safe in the knowledge that
it is for a limited period only.
However, you will find that within a short while people will discover
they didn’t need to control everything at all. They have learnt to control what is
important. They will acquire a new
confidence and at the end of the trial period you will find that the subject
has been “forgotten” about. Indeed
don’t even mention the matter again.
Effectively the cloud is broken.
We now have the following;
To break this
cloud we must remove the old action that caused the problem. But remember there was an assumption that
the old action answered. Let’s draw
that in.
For example,
reduced work-in-process will meet a new system need for reduced lead times,
but people worry that it will cause the constraint to slow down; because of
an old assumption that work-in-process waiting causes people to work
faster. The solution here is to reduce
work-in-process more gradually than is necessary so that people can gain
confidence that the new need, short lead times and the old need, keep the
constraint busy are both met. Both of these
alignment methods are really trying to bring about effective subordination. Let’s restate
this. We could
rewrite the clouds that we drew above as a slightly more generic case. This is how
most people will initially see the implementation – falsely. Their experience from TQM, TPM, kaizen,
ABC, ISO900 and many other detail complexity methods will be that the sum of
the local improvements equals the global improvement. We know that this is not so. We have to change the wording of the second
need – “protect the local optimization is incorrect. Let’s do that. Now we see the
real needs, we must protect the global optimization and subordinate the local
optimization. To do that we must not
control everything and once again we can break the conflict. Let’s repeat
is one more time, effective subordination is the key to successful
TOC/drum-buffer-rope implementation.
Dettmer shows
a powerful cloud that must also be satisfied in a manufacturing environment –
and all other environments for that matter (5). Let’s have a look at it.
Let’s look at
the assumptions underlying the arrow between “good of the individual” and
“maintain status quo.” How do we raise
these assumptions? Well try reading
the cause and effect to yourself and at the end add “because.” For instance; in order to satisfy the good
of the individual we must maintain the status quo because… Dettmer lists
a number of generic assumptions; assumptions about the status, security and
authority of the individual. Let’s
draw these in.
If the
work-in-process is reduced throughout the plant, then this visual indicator
before and after the work center will be reduced. So too will the feedback and feel-good
factor that the line worker experiences even though he is working just as
well or even better. To break this
cloud you must hook up the job security and job satisfaction in some way to
the global objective or else the security and satisfaction of the worker is
threatened and no improvement will take place. In some
countries, lack of work-in-process is indicative of upcoming lay-offs, there
is no reason for anyone to believe at first that this is any different from
the past (except that the decrease in WIP is a consequence of proper
scheduling rather than decrease in sales demand). So you must tie the status and satisfaction
to the new conditions and reinforce these whenever you can. Theory of
Constraints is not like TQM or kaizen where everyone everywhere can make a
positive contribution by doing new or better things. Everyone is still making a contribution in
Theory of Constraints; however, often it is passive – by not doing old
things. This brings us back to where
we started. Effective subordination is
the key to successful Theory of Constraints implementation. (1) Kawase,
T., (2001) Human-centered problem-solving: the management of
improvements. Asian Productivity
Organization, pg 209. (2) Goldratt, E. M., (1999) How to
change an organization. Video JCI-11,
Goldratt Institute. (3) Lepore,
D., and Cohen, O., (1999) Deming and Goldratt: the theory of constraints and
the system of profound knowledge. The
North River Press, pp 140-143. (4) Cole, H.,
(1998) Implementing distribution – layers 4-5. Video JMT-16, Goldratt Institute. (5) Dettmer,
H. W., (1998) Breaking the constraints to world class performance. ASQ Quality Press, pp 207-225. This Webpage Copyright © 2003-2009 by Dr K. J.
Youngman |