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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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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Thinking Processes – Prerequisite Tree

The Prerequisite Tree (PRT) is one of the Logical Thinking Process tools, mentioned among the Thinking Processes by the Theory of Constraints community.

The Prerequisite Tree is used to surface and overcome obstacles to achieving the change towards the organization’s Goal by setting Intermediate Objectives (IOs). These IOs are sequential steps to implementing the change or steps helping to overcome or neutralize the obstacles.

The Prerequisite Tree is a necessity logic-based tree, like the Goal Tree and its building starts from the Goal or objective downwards. The objective may be the result of an injection identified in a prior Future Reality Tree (FRT). The implementation sequence starts from the bottom up to the top as each layer is dependant on the layer underneath.

The underlying IOs are the tasks required for attaining the objective. If Obstacles surface, additional IOs are required to bypass or neutralize them.

IOs are depicted in square cornered boxes while obstacles are depicted as hexagons or “stop signs”.

Prerequisite Tree

Prerequisite Tree

The graphic convention I use is the one recommended by Bill Dettmer, putting the IOs on top of the obstacles they help to overcome. The original convention is to put obstacles on a side between two IOS and link them with an arrow to the arrow linking the IOs.

Prerequisite Tree original design

Prerequisite Tree original design

The Prerequisite Tree is the preparatory work for the coming implementation action plan as well as a useful communication tool and a means to overcome fear and/or resistance to change. Obstacles may be stated in sentences starting with “yes, but…”.

The related Intermediate Objective(s) prove there is a way to neutralize, bypass or overcome the obstacle.

Obstacles may be real, not only reluctance or fear about change. The lack of a specific required know-how is a valid obstacle and the corresponding IO may be hire the needed know-how or develop it by training.

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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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Goal Tree: How to define Critical Success Factors?

The original name of Goal Tree is Intermediate Objectives Map, an adaptation of the Theory of Constraints’ Thinking ProcessesPrerequisite Tree (PRT). IO Map just as Goal Tree displays a logical tree-structured suite of Intermediate Objectives.

Prerequisite Tree

Prerequisite Tree example

>Read William Dettmer’s paper about IO Map

Critical Success Factors (CSF) are high-end objectives necessary to achieve in order to achieve the organization’s Goal. Conversely, failing to achieve one CSF means failing to achieve the Goal, thus the name ‘Critical’.

Top management is usually able to state the organization’s Goal, yet stating CSF properly is more difficult than it looks at first glance.

How many CSF?

The purpose or Goal of an organization should not require too many Critical Success Factors to be achievable. Too many of them means the ambition is maybe too high or some CSFs are in fact Necessary conditions mistaken as CSF.

Too many CSFs would simply mean that the Goal is subordinate to too many objectives thus easily endangered. For top management, reviewing, monitoring and managing too many top objectives is distracting and the risk of losing focus increases with the number of CSFs.

I recommend to limit CSF to five. This of course is no absolute limit, but a good start. It requires top management to pick only few really vital, relevant and consistent objectives.

>Read about this company with 20+ “strategic objectives”

CSF tips

What are CSF and how to state them? Here are some tips.

In for-profit organizations and except if in dominant position or in a ‘blue ocean’, the organization faces competition and it is very likely that meeting price, delivery and quality requirements are three Critical Factors. These three are imposed by market, competition and generally speaking external forces.

These external forces will dynamically influence those factors and in order to keep on competitive edge, company may have to adjust permanently.

If one of these three CSF is not met, the company may not be able to compete. End of story.

These three CSF are generic and common to all competitors, this leaves two CSFs to distinguish the company from others. The tip here is to state them wisely to differentiate from others, something that makes the company unique.

SMART statement

CSF statement as for any objective should be SMART. Something like “keeping our quality at best” or “improving our quality” is not SMART, it’s fluffy.

>Read more about SMART CSFs

Almost any contribution can claim helping to improve quality or keep it high, what ever this means. and this would mean contributors are done?

A SMART statement about quality should sound like: “In one year from now our first pass rate is steadily above 98%”.

With such a statement, people in charge and contributors know what they must strive for.

The same applies to any CSF. What does “improving customer relationship” mean? How is it meant to be measured or assessed?

Don’t confuse CSF with Necessary Conditions

It happens often that CSFs and Necessary Conditions are mismatched. Necessary Conditions (NCs) are subordinate (intermediate) objectives compared to CSFs. Just as CSFs, NCs are linked up and downwards to others by a necessity logic relationship: if in order to achieve A we need B, B is a Necessary Condition to A.

What is tricky is CSFs have the same relationship with the Goal, therefore easy to mismatch with NCs. How to distinguish CSFs from NCs? Put plainly, if no higher objective can be inserted between one objective and the Goal, this objective is most probably a CSF.

Example of mismatching: costs, price and margin

Senior managers often suggest “mastering costs” as CSF, which sounds legitimate. But do customers or market care about company’s costs? No, they care about sales price because this is what they have to pay or at least on what they base decision to go for buying or not.
Sales price is higher in rank than costs because price will determine if the company is still in competition or not, not costs.

A startup can challenge the market with aggressive price policy, not with its costs management. This same startup can even write red figures some time, what matters in first place is to conquer market shares through its interesting offering.

Margin is probably also higher rank than costs, because the later surely do influence margin (Price-costs=margin), but it is easier to set a margin level as objective than to foresay future costs. Costs come in many ways: overhead, material, operating expenses, labor, etc. Some costs are a lever to control both sales price and margin, while others are given, non-negotiables. Managing costs is therefore a Necessary Condition, not a CSF.

Example: certification

Some organization operate in a regulatory constrained environment, like aerospace or pharma, where some official certifications are mandatory. Getting and keeping such certification is certainly strategic yet not a CSF, but rather a Necessary Condition and a low level one.

What does it mean? To be authorized to operate in such industry, the certification is a basic requirement which comes early when establishing the company/ the business. This kind of ‘basic’ condition is located near the base of the Goal Tree as without it no operation that goes to the public is allowed.

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Prerequisite Tree and Hoshin Kanri


Chris HOHMANN – Author

During Lean Summit 2012, keynote speaker Laurie West promoted Lean transformation using Policy Deployment, another name of Hoshin Kanri. During his speech, Mr West listed five obstacles hindering the strategy deployment:

  • People can’t implement something they don’t know
  • People can’t implement properly something they don’t understand
  • People can’t implement something they don’t stand for
  • People quit implementing if negative side effects appear
  • Management does not pay enough importance to “How to”

These obstacles call for Prerequisite Tree (PRT) one of the Thinking Processes (TP) tools, designed to bypass or neutralize obstacles that stay in the way for fulfilling a given objective.

Prerequisite Tree leading to Hoshin Kanri

In a PRT, the objective is in the topmost scare cornered box, written in present tense, a way to state firmly there is no doubt about this objective to become a reality.

In our case, the objective is stated as: “Strategy is deployed and implemented with success”.

Yet five obstacles are in the way. Starting bottom left, the first states ” People can’t implement something they don’t know”.

To overcome this obstacle, an Intermediate Objective (IO) is necessary. IOs are stated in present tense and our first one reads “Strategy is communicated”. Once this objective reached, e.g. communication about strategy done, the obstacle “People don’t know” is no more valid.

Reading a PRT is simple; obstacles are placed in hexagons, while Intermediate Objectives are placed in scare cornered boxes. There is a timeline to be considered, a logical progress from the lowest level obstacle to the topmost objective, hence this PRT is to be read from bottom to top.

The right branch figures when and how People will be actively involved in Policy / Strategy deployment and implementation.