Unintended consequences are undesired results that occur from the actions we take. In a sense, they are an equal and opposite reaction to whatever action we have taken on the system. Sometimes (rarely, it seems), unintended consequences can be good. Often, however, they are not good. For that reason, we call the tool used to understand and prevent or mitigate the potential negative effects a "negative branch," or NBR.
The distinction between obstacles and NBRs is that obstacles prevent you from achieving the future reality or ambitious goal you have set. NBRs come about because you have succeeded in creating the injection you intended to create. The injection, combined with other factors in current reality (or, sometimes, with new factors also created in future reality), conspire to cause a negative outcome.
The major resource for identifying potential NBRs is the people who review your FRT. They have the intuition to understand how the changes you are going to create may interact with their reality to create an unintended consequence.
Figure 11.6 illustrates a potential NBR dealing with the commonly voiced concern that if you make the safety time in the schedule evident, people will want to cut it. People usually include both customers and more-senior management. The project-management literature addresses that concern, often with a caution to keep your safety time hidden. That hardly seems like a professional way to run a business!
You first build the tree to connect the injections expected to cause the UDE to the stated UDE. The NBR is a sufficiency tree, just like the CRT and FRT, and is read IF/THEN. By this time, I trust you have sufficient comfort with the construction to read the tree. You must check the tree to ensure that the entities and causalities exist and that the logic is complete and sufficient.
The next step in using the NBR is to find an injection that will prevent the negative effect. You do that by examining the branch and locating the point at which it turns negative. In the case of this figure, the branch turns negative at entity 602, "The customer wants lead-time reduced by cutting buffer times." You then assess potential assumptions under the causality arrows that feed that entity. In this case, since only one causality feeds entity 602, you have to look at only two arrows. Note that since the connections from 600 and 601 to 602 include an "and" illustrated on the tree by flattened ellipse called a "banana" by TOC practitioner eliminating either 600 or 601 results in eliminating the effect, 602. That is the meaning of the "and." You need both feeding entities for the effect to follow.
In this instance, entity 601 appears to be a fact of life, so there would be little advantage to questioning the assumptions surrounding its existence or causality. There are assumptions in the causality between 600 and 602, the most obvious one being, as noted on the tree, "Because the customer sees cutting buffers as the biggest and most opportune way to meet their need." That is likely to be a true assumption when the customer (which may be internal management) does not understand the ideas behind CCPM.
Once you have an assumption, you can propose alternative injections that make the assumption no longer correct or applicable. Two potential injections are presented in Figure 11.6. Either injection should do the job of eliminating the assumption and therefore preventing the UDE of this NBR. Take your choice.
The NBR procedure follows:
1. Identify the potential UDE of concern.
2. Identify the injection you suspect leads to the UDE.
3. Build a sufficiency tree to connect logically the injection to the UDE.
4. Scrutinize the logic in the tree (branch) by reading it aloud to others and having them agree to the logic.
5. Determine where the branch first turns negative.
6. Expose the assumptions under the arrows feeding the first negative entity on the branch.
7. Identify injections that will invalidate the assumptions and, therefore, prevent the negative effect.
It is, of course, possible that the injections you propose to trim the NBR may themselves lead to unintended consequences. If so, examine the new NBRs before completing the strategy.
The NBR can be of great help in project-risk management. It helps a team clarify the causes of potential risk events and, thus, to identify prevention and mitigation measures to avoid or reduce the probability of those causes or to plan for mitigation should the risk event occur.
An injection is not a plan. It is not even a coherent strategy. Goldratt suggests the following tools for such purposes.
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What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.