Theory of Constraints Handbook - James Cox Iii [508]
As we explore the full, integrated TOC TP, I will use examples from the case study of a bank, which was described in detail by Cox, Blackstone, and Schleier (2003) in their book, Managing Operations: A Focus on Excellence. (Used by permission, © Cox, Blackstone, and Scleier)
What to Change?
Mad let us grant him them, and now remains that we find out the cause of this effect—Or rather say, the cause of this defect, for this effect defective comes by cause. Thus it remains, and the remainder thus.
—William Shakespeare
In order to answer the question, What to Change?, we will use two of the TP tools: the CRT and the EC. Over the years, two approaches have emerged as “standard.” The “Snowflake Method” is considered to be the more traditional approach, mainly because it is an older method than the “Three-Cloud Method,” and the “Three-Cloud Method” is generally easier for people to learn. The main difference between the two approaches is the sequence in which the two tools are used, and in which the core problem is identified. The “Three-Cloud Approach” tends to be easier to learn. Both methods have proven to be quite effective in gaining an understanding of the situation and the core conflict (core problem) that has prevented the otherwise natural harmony to be in place.
Current Reality Tree (CRT)
We find in the course of nature that though the effects be many, the principles from which they arise are commonly few and simple, and that it is the sign of an unskilled naturalist to have recourse to a different quality in order to explain every different operation.
—David Hume
A CRT is a cause-effect model of an existing situation. The main use of a CRT is to answer the question, What to Change?, so the cause-effect relationships that are focused on in the CRT are the UDEs—the aspects of the situation that we want to improve.
One important aspect of the inherent simplicity concept is convergence. Goldratt explains that “science is simply the method we use to try and postulate a minimum set of assumptions that can explain, through a straightforward logical derivation, the existence of many phenomena of nature” (Goldratt and Cox 1986, Introduction). When we look at a well-constructed CRT, we are able to see clearly the very few causes for a much larger set of effects.
The grand aim of all science is to cover the greatest number of empirical facts by logical deduction from the smallest number of hypotheses or axioms.
—Albert Einstein
Evaporating Cloud (EC)
The peak efficiency of knowledge and strategy is to make conflict unnecessary.
—Sun Tzu
By definition, a problem is something that we want to solve. In other words, if I have a problem, then I want to replace it with its opposite non-problem. Whether a given problem is a core problem (the cause for many UDEs), or an UDE (an element of the system that is undesirable), it is an obstacle to harmony that should be eliminated. This means that any problem can be verbalized as a conflict, which leads us to the use of the EC. In the “Snowflake Method,” the EC is used to summarize a core problem reflected in a CRT that has been constructed by logically connecting the UDEs. In the “Three-Cloud Method,” the Cloud is used to derive the core problem and then logically connect it with the UDEs.
The “Snowflake Method”
1. Pick a subject matter. What is the system or situation that you want to understand better in order to improve it? Perhaps you want to understand your markets better to develop a product or offer that would address a significant need; or you want to understand your organization better to determine why it is not growing faster, serving its customers better, or retaining its employees longer; or you want to understand your supply chain to find the keys to improving the relationships with both your suppliers and your customers; or you want to understand your family or other relationships better to figure out what to change to make them more meaningful. Hospitals have used the TP to understand what needed to change to improve their