Reader question: Goal Tree vs. Current Reality Tree

Here is a reader’s question: I have difficulty seeing the difference between the Goal Tree and the  Current Reality Tree (CRT). With these two trees we assess the process. What are the main differences between the two?

The Goal Tree and Current Reality Tree (CRT) have nothing in common. They are not even meant to care about processes but about the system as a whole. Neither the Goal Tree nor the CRT are process maps.

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A Goal Tree lists all Necessary Conditions to achieve a Goal, which is not yet achieved, so it is about the future.

The CRT describes why the Goal is not yet achieved in the current state. It starts with identified Undesirable Effects (undesirable for the system as a whole) and drills down to the few critical root causes.

A Goal Tree is built from top-to-bottom with necessity logic while the Current Reality Tree (CRT) is built from top-to-bottom using sufficiency logic. This building top-to-bottom is maybe the sole commonality between the two.

The name Current Reality Tree is somewhat misleading because the CRT is limited to the description of the negative outcomes. It does not describe all the Current Reality. This is saving a lot of unnecessary analysis as well as a warning to not mess with what is currently producing Desired Effects!

What could have caused some confusion to my reader is the fact that a Goal Tree is a benchmark against which to measure the gaps in current reality.

When doing this I use a 3-color code to indicate each Necessary Conditions status. I assess the current condition of the system with the Goal Tree as benchmark. The first autumnal-colored tree should be kept as is as a snapshot of the situation at the beginning. Distinct trees are used later to monitor the progress of ‘greening’ the tree, i.e. closing the gaps to achieve the Goal.

I hope this helps to understand the differences between a Goal Tree and a Current Reality Tree.

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Scrutinizing and improving a Current Reality Tree (video tutorial)

In this video, I scrutinize and suggest improvements on a Current Reality Tree (CRT) found on the Internet. A logically sound CRT is key to convince audience about the robustness of the analysis and the reality of the causes to the trouble. If there is room for doubt or the logical has flaws, chances are that the audience will not buy-in, especially those having some “skin in the game”…

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Beware of the Logical Thinking Process apparent simplicity

It happens often with methods and tools that look simple: people giving it a try think they master the subject when in reality they more or less failed with their trial. It is not different with the Logical Thinking Process.

The Current Reality Tree is maybe one of the logic trees the most attractive to rookies. The classic Theory of Constraints’ Thinking Processes as well as Bill Dettmer’s Logical Thinking Process propose a structured and step-by-step approach to go from gathering “undesirable effects” or UDEs to revealing the root causes via a Current Reality Tree (CRT).

Even so the two approaches have slight differences, they follow the same construction and analysis pattern and both the stress the need to build the CRT with the mandatory logical soundness. Therefore there are rules to follow as well as a check process called the Categories of Legitimate Reservations (CLR).

Alas, what most people recall is that the Current Reality Tree is built by connecting UDEs with cause-and-effect sufficiency logic relations using a simple if…then… verbalization. Then, look at the bottom of the tree and somewhere there lies the mother cause of all evil. Kill this root cause and the whole tree of negative consequences will collapse. Tada, job done.

The apparent simplicity of building a CRT and some overconfidence, mixed with the laziness to go through thorough checking ends up with disappointing trees which are not logically robust.

Besides the risk of failing to find the right causes to problems and consequently proposing inappropriate solutions, the analysts may be taken by surprise by someone listening to their brilliant demonstration and pointing out flaws of logic. Embarrassing.

This can be devastating, because even if the analysis is ultimately leading to the real core problems, the doubts raised during a flawed presentation may end up in disbelief or rejection of the conclusions.

As Bill Dettmer warns in his personal style at the end of his 6-day intensive Logical Thinking Process Training Course, “You are now armed and dangerous”. In essence he gave the participants potent weapons, but their lack of practice may lead them to shoot themselves in the leg.

Well, considering my own scars, I can only agree.

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What advice to people wanting to experience the Logical Thinking Process Training Course?

Paris June 28th, 2017. The 6-day Logical Thinking Process Training Course with Bill Dettmer is just over. We asked the participants not in a hurry to rush to an airport or train station if they would share their thoughts about the course in front of a camcorder?

Cédric, Sverre and Leo were so kind. Bill asked them about their favorite takeaways and advices for people willing to take the course.

As a veteran with 5 attendances (being part of the organizing party) I delivered my testimony long ago, however, I reflected on what I would say now.

My favorite part of the course changed over the sessions, which is understandable with all that repeat. Now my favorite part is working hands-on on trees, cross presenting them and have them scrutinized. That’s the closest we can get in a room session while working on somebody’s real-world case.

This brings me to my advice: come prepared (read the pre-course reading material) and have a real-world problem to work on. The best is a problem with which the participant has enough inside knowledge and enough influence – if not power – to make change happen.

What happens during the course?

This last June 2017 session was in my opinion a good one because the cases were mostly about founding a new business, spinning-off from actual one, or trying to reinvigorate an existing fading one.

With entrepreneur spirit and most of the options open, the Goal Tree was piece of cake. Well it seemed to be piece of cake. Once in front of a large empty sheet of brown paper and a demanding mentor in the back, the candidate entrepreneurs had to turn their brilliant idea in a compelling and robust Goal Tree.

The Current Reality Tree (CRT) brought most of them back into their unsatisfactory actual state, but at least with clear understanding of what causes the Undesirable Effects (UDEs). Conflicting objectives or decisions were uncovered and creativity called in to dissolve the conflicts.

Logical Thinking Process / Theory of Constraints’ Thinking Processes aware readers recognize the Evaporating Cloud (EC) to do that.

On the group went, injecting solutions into their current reality in order to turn the UDEs into Desirable Effects (DEs). This was done thanks to the Future Reality Tree (FRT), a kind of logical (and virtual) proof of concept to test the solutions.

Bill instructed the group to look for possible Negative Branches that may grow out of a seemingly brilliant idea and end up in a new and unexpected UDE. When such a branch is spotted, the trainee can be happy to have tested the solution on paper before messing up in real world! Luckily there are ways to trim such unwanted negative branches and it’s part of the training.

The final exercise is to list the possible obstacles to implementation and overcome them with a Prerequisite Tree.

Five trees per attendant gives a lot to review and scrutinize! And just as many learning opportunities!

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Limits of Logical Thinking Process

In this excerpt of day one from the 6-day Logical Thinking Process training course, Bill Dettmer explains that the very front end, the two first tools (Goal Tree and Current Reality Tree) are deterministic, based on facts. The other steps and tools are about future, which can only be based on probabilities.

At the end of this short video, Bill gives his definition of the Logical Thinking Process.

Bill Dettmer refining some points about Logical Thinking Process

In this video, an excerpt of Bill Dettmer‘s Logical Thinking Process (LTP) training course in Paris, June 2015, Bill refines some points about LTP.

First, the two first tools (Trees) of the LTP, namely the Goal Tree (GT) and Current Reality Tree (CRT) are based on facts. The others, Evaporating Cloud (EC), Future Reality Tree (FRT), Prerequisite Tree (PRT) are based on high probability things will happen as planned.

The components of a Goal Tree, called Necessary Conditions (or NCs) are factual needs necessary to achieve the Goal. The Current Reality is described in a CRT in a way that can be checked and proven, based on facts.

As soon as the people are working on the future, from Evaporating Cloud on, it can only be described in probabilities, as things may not exactly turn out as planned. Theory of Constraints’ Logical Thinking Process may need to rely on other tools and methods than Negative Branch Reservation (NBR) to mitigate the risks.

Furthermore, the time to accomplish the necessary tasks is an evaluation at best.

Finally Bill summarizes what Logical Thinking Process is:

a structured way to move from an ill-defined system level problem to a fully implemented solution.

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Rotate a Tree to start your project

During the Logical Thinking Process training course (June 2015), Bill Dettmer took us through the whole process and the associated tools at each step.

The process starts with the famous Goal Tree, assess the current situation and focus on critical root causes with the Current Reality Tree (CRT). Conflict Resolution Diagram (AKA Evaporating Cloud) may be used to resolve conflicting objectives and find solutions (called “injections”) to turn the CRT into a Future Reality Tree (FRT).
But in order to get to the future state, some obstacles will have to be removed or by-passed. This is done with the help of a Prerequisite Tree (PRT).

Once the PRT is ready, it is a kind of logical proof of concept. In order to turn this POC into real action, Bill shows how rotating a Prerequisite Tree gives an almost ready-to-use project network. Therefore, Critical Chain Project Management (CCPM) is the sixth tool of the Logical Thinking Process.

By the end of the demonstration, Philip Marris highlights the “beauty” of this process, patching one of Critical Chain Project Management “weaknesses”: how to ensure what is to be executed as a project is meaningful? He does this by giving a sadly funny and true example in aeronautic industry.

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Logical Thinking Process

LTPThe Logical Thinking Process refers to the work of William (Bill) Dettmer summarized in the book of the same title. The Logical Thinking Process (LTP) is a one to six steps* process using sound logic and a set of tools (or processes) to provide executives and system managers an effective method for designing organizational strategy, planning its deployment, evaluating its effectiveness, and making corrections as needed in the shortest possible time.

Bill Dettmer & Chris Hohmann

Bill Dettmer & Chris Hohmann

*the number of steps required or used may vary by necessity or choice/experience of the practitioners

It starts with the Goal statement, the Vision or what the Lean community refers to as “True North”. The Goal can be set only by those who created the system, the system owners or those having the responsibility to conduct the organization toward the Goal set by the founders.

The Goal is dependent upon a series of Necessary Conditions, among which some high level terminal outcome are called Critical Success factors. The visual representation from the Goal down to Necessary Conditions forms the Goal Tree.

The Goal Tree is a benchmark but the actual condition of the organization may not be the one required.Thus the Goal Tree gives input to the next tool in the Logical Thinking Process: the Current Reality Tree (CRT).

With the CRT, the organization is assessed or “audited” about gaps between the Goal Tree requirements and the actual condition. Gaps lead to Undesirable Effects or UDEs. These UDEs are the inputs for the next tool: the Future Reality Tree (FRT) in which the UDEs are neutralized with “injections”; causes or conditions not yet existing and designed to turn UDEs into their opposites: Desirable Effects (DEs), without bringing negative side effects.

Logical Thinking Process
Between CRT and FRT is another tool, called Evaporating Cloud (EC) or Conflict Resolution Diagram (CRD). It is specifically used to solve conflicts, like going for small batches wanted by sales and going for big batches wanted by production, for example. Each party has good reasons to demand for what they see as being the best, but usually the conflict is based on false assumptions the EC helps to surface and then “evaporate” the conflict.

The Prerequisite Tree (PRT) is the next tool of the LTP. It is used when stakeholders argue about obstacles to implement the solutions found with the FRT and EC. Every obstacle is then neutralized or by-passed with Intermediate Objectives (IOs), smaller necessary steps and conditions to fulfill in order to bypass the obstacles.

Finally the Transition Tree (TT) is a kind of detailed action plan but still at system level. Actions, combined with the actual reality and the needed condition lead to the desired new reality and closer to the Goal.

Rational, logic, robust

All the Trees and the Cloud are based on logical relationships between their entities, which makes them as well as the whole process unbiased of beliefs, false assumptions, emotional and irrational choices, and filter out irrelevant or unnecessary “nice-to-haves”.

The result, if correctly built, is a very robust and complete roadmap to the next level towards the organization’s goal.

The various tools, especially Goal Tree, Current Reality Tree, Evaporating Cloud and Future Reality Tree may be used as stand-alones or in combination. When rolling out the whole Logical Thinking Process, the work group may stop when the FRT is complete and checked, as they feel no need to get into more details with the next trees.


Don’t be afraid by all the metaphoric jargon, it must be learnt but is not that hard. All the available body of knowledge relies on this jargon and it’s the Theory of Constraints community lingo. No way to do without it, like it or not.

Thinking Processes versus Logical Thinking Process

There is a subtle difference between Thinking Processes – plural – and (Logical) Thinking Process – singular.

  • The Thinking Processes refer to the five tools, four trees and one cloud, from CRT to TT and do generally not include the Goal Tree.
  • The Logical Thinking Process is the process described previously, using the same tools plus the Goal Tree. Bill Dettmer keeps considering the trees and cloud as tools, not as processes and sees only one overall process.

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A perfect world is a lovely place


Chris HOHMANN – Author

It happened during a project review meeting during which we went through the planned action sequences. A new late comer to the project raised a few questions and suggested some additions and changes to the action plan.

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One of the participants, visibly irritated by the new entrant and his interventions, snapped back: “A perfect world is a lovely place, but we need to focus on our goal without seeking perfection.”

He was referring to the constraints and difficulties limiting our possibilities and options and obviously trying to silence the newcomer.

As moderator of this meeting I calmly explained that at this stage of the project, any suggestion that contributes to its robustness is welcome. Furthermore, a description of perfection is always interesting.

Indeed, the ideal or perfect solution may be out of reach for the moment, but this does not mean that all options must be rejected. An evolution of the strategy, economic conditions, regulatory, state of mind of the decision makers or technology can reshuffle the cards and open the field of possibilities.

In such a case, having a complete description of an ideal future state can be a big time saver. In addition, the ideal solution is a reservoir of ideas for future improvement and it makes sense to revisit these options periodically. One or the other constraints could disappear and new options become possible.

Generally speaking, an ideal future state can always be degraded by incorporating the various constraints, but building a solution around existing constraints without exploring breakthrough alternatives typically falls within the 8th type of Lean waste: not using people’s creativity.

The meeting resumed in a little tense atmosphere due to the enmity between the two individuals, but with the new suggestions taken into account.

When it comes to Value Stream Mapping (VSM) and sketching the future improved state (Value Stream Design or VSD), the above explanation applies perfectly.

It makes sense to study the ideal target first and then to degrade it by integrating the different constraints that may not be eliminated or bypassed in reasonable time or cost.

Those readers familiar with the Thinking Processes of the Theory of Constraints certainly try to challenge the reality of the constraints with specific tools like the Current Reality Tree (CRT) and the Conflict Resolution Diagram (CRD, aka Evaporating Cloud).

At the time of this meeting, I used a Goal Tree previously built with the participants but couldn’t investigate and challenge the constraints.
It is very likely that among the listed constraints, some are more a matter of beliefs, myths and misunderstandings or misinterpretations than real constraints.

If these false constraints can be surfaced and eliminated, the solution will certainly be better and it will prove the value of exploring the ideal state before giving up too soon.

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Thermodynamics of Eternity or Current Reality Tree in Hell

Paris, November 2014, Bill Dettmer was guest of Marris Consulting. I was fortunate to be among the guests for videotaping interviews.

In the following video, Bill introduces the Current Reality Tree, first of the Thinking Processes tools, with an uncommon example.

>Previous video: Video interviews with Bill Dettmer: LTP training participant’s testimony

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