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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 |