Theory of Constraints Handbook - James Cox Iii [469]
[D-D′ 2]: I don’t know what value there would be in meeting with Bill.
Graphically, the causality arrows are described in text boxes containing the underlying assumptions that are pointing to the relevant arrow as in Fig. 24-1.
Step 6. Construct your solution and check it for win-win.
A solution to the problem is a change to the reality that removes a major reason for the existence of the Cloud. The way to achieve objective A is through the removing or invalidating one of the significant underlying assumptions. When a major assumption is invalidated, then there is no reason for the logical connection to exist and hence one of boxes may disappear from the reality, causing the conflict to disappear or evaporate. Hence, this process is called the Evaporating Cloud (EC).
Theoretically, we can challenge every arrow on the Cloud. However, from a practical point of view we want to make the changes on the tactical level; hence, we challenge the assumptions underlying B←D, C←D′ or D′D′.
Usually we can expect that after building the Cloud and the thorough logic check in Step 4 that the objective A and the needs B and C are well defined. B and C have been confirmed to be significant, positive, and necessary conditions for achieving the objective stated in A. Accepting A, B, and C directs our efforts to solve the conflict between D and D′.
To invalidate or negate an assumption, we must introduce something new to replace it. This “something new” is called an injection.5
The injection is the change in reality that helps achieving the statement in the box at the tip of the arrow (B or C) without having the situation described in the box at the base of the arrow (D or D′).
Under the current reality, the perception is that the only way to achieve B is through taking the action D and the only way to achieve C is through taking the action D′. The injection for B-D is a new facet to the reality so that B can be achieved. This injection is a valid solution only if it is also not in conflict with D′. Alternatively, the injection for C-D′ is a new facet to the reality so that C can be achieved and B is not jeopardized. This injection is a valid solution only if it is also not in conflict with D.
Therefore, we have three potential options for breaking the Cloud:
Injection to B-D assumption that replaces the use of D.
Injection to C-D′ assumption that replaces the use of D′.
Injection to D-D′ assumption that removes (or changes) both D and D′ and suggests a new common tactic.
Conceptually, it is possible to find an injection for all three options.
Finding an injection is an important step in the process. The general recommendation is to try to think “outside the box” and ask yourself the following question: “In what situation is the stated connection between two boxes of the Cloud not valid?” You may think about a different scenario, a different environment, or experience from the past in which the connection was not there. Many times we have the injection in our head under the heading of “I wish the situation was different . . .” We claim that when people have a problem bothering them they continuously think about solutions. Nevertheless, people tend to erase their own potential solution assuming that the solutions are unrealistic or impossible to implement. The EC method is the place to consider options and ideas that were dismissed before.
To practice the process of finding injections and to ensure that all possible options are considered, we recommend searching for injections to break the B-D, C-D′, and D-D′ arrows. Once we define a variety of injections, we can choose which one (or ones) we prefer to use. The selection of the arrow to break may have an impact of the acceptance of the suggested solution. The arrow, corresponding assumptions, and injections are shown in Table 24-3.
Once you have all the potential injections, you can decide to choose one or more of them or even create a new injection that will take elements of some of the stated injections.
The solution has to work for you. That means that you are comfortable