A Guide to Implementing the Theory of Constraints (TOC)





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3 Cloud Method

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Breaking The Box

Let’s start with a box; it is open at the top.  Inside is the problem, the conflict, the current dilemma that we face and that we wish to resolve.  We are used to being told to think outside the box, but let’s see if we can carefully unfold the box and therefore break right out of it completely.

Let’s fold down the front – it’s made of cardboard, we are too young to remember that boxes were once made of wood.

Now let’s fold down the back.

And also the sides.

Nothing inside?  Well not quite.  There is a cloud on the bottom.  Let’s have a look from directly overhead.

As we have seen throughout these pages, a cloud is simply a graphical means of causing us to verbalize and order our understanding of an underlying conflict or dilemma.  To describe the entities in the cloud let’s go back to one of Goldratt’s earliest explanations (1);

“A general presentation should state that we would like to accomplish some objective, which we will denote by the letter A.  In order to accomplish it, we find out that at least two requirements, B and C must be filled.  Assume that we logically derive the fact that in order to fulfill B we must have D (or we must have more of D), but in order to fulfill C we must not have D (or we must have less of D).  We have a conflict.”

So we write on the bottom of our box; the objective, the two requirements B and C, and the two prerequisites – more usually called D and D’ (D prime) rather than just D as in this early description.   So, what then of the sides of the box?  What are we going to do with those?

Well, under each of the arrows in the cloud there are inherent and unverbalized assumptions.  Let’s draw these in.

Thus, the walls of our box are no more than our current assumptions – both metaphorically and here literally as well.  To break the box we must ensure that no invalid assumptions are allowed to go unchallenged.  Of the remaining valid assumptions; we must seek out ideas to overcome those which might hinder us.  We have to break down the walls of the box – not just think outside of it.

As you learn more of the power of using clouds, come back to this analogy and see if it helps you to understand clouds better.


(1) Goldratt, E. M., (1987/88) Essays on the Theory of Constraints.  North River Press, Chapter 2 pg 2.  Originally published in the Journal of the Theory of Constraints.

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