Thinking Processes – Current Reality Tree

The Current Reality Tree (CRT) is one of the Thinking Processes logical tools. As the name tells, it depicts the current reality* in a series of dependent logical cause-and-effect relationships, starting from Undesirable Effects down to one or a few critical root causes.

A root cause may also be called “core problem” or “core driver” in the original concept.

*Current Reality is somewhat misleading as it is only focusing onto the negative outcomes and what prevents achieving the Goal. This shortcut is a pragmatic choice made for the sake of solving the problem and improve the situation, not to fully map the as-is situation. In other words, we don’t care about what actually works. Besides, the Current Reality depicted in a CRT is a snapshot at a given moment.

Undesirable Effects (UDEs) are often called “problems” that people perceive, suffer from or have to cope with, but UDEs are most often only symptoms of deeper laying problems. The CRT is a tool that helps to identify and address the critical root cause(s).

As for many elaborated problem solving methods and tools, building a CRT is not required for every problem. It was specifically designed to solve complex, multi-factor and system-wide problems.

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Reading a CRT

It takes some experience to build a robust Current Reality Tree, which should not be done by a single person for the sake of robustness, and the best is to get used to read them first.

Current Reality TreeA CRT is conceptually supposed to have more or less a V shape with the topmost and numerous UDEs on the top, other UDEs that are causes from topmost UDEs and their own causes, and so on down to the few critical root causes, usually located (near or) on the base of the CRT.

While convenient for explaining the theory, the actual shape of a CRT is seldom looking like a nice V!

Once a tree is completed, it can be read either top-down or bottom-up. The construction is always top-down, from symptoms to causes to critical root causes.

A CRT is made of entities which are round-cornered boxes holding a brief description of a fact in present tense. Entities are either causes or consequences and most of them are both.

Entities which are linked have an arrow between them. The base of the arrow reads “if…” and the tip reads “then…”.

When reading a CRT top-down, the succession of linked entities reads “entity B exists (tip of arrow points to it) because of entity A (arrow starts from it)”.

When two or more arrows point to an entity, the entities at the base of the arrows are possible causes. The different arrows are logical “inclusive OR” relationships.

When the arrows are encircled by an ellipse, it means logical “AND” relationship: all the causes must exist simultaneously for the effect to exist.

Theory of Constraints is about focusing and leveraging, so does the CRT. The purpose of a CRT is to search for the root cause and while eliminating it, the whole tree of dependent UDEs disappears.

The investment of analyzing the situation with a CRT is really worth it, compared to the useless and wasted efforts trying to solve all the UDEs. Concentrating efforts on the sole critical root causes is much more efficient.

CRT example

Here is one half fictitious example of a CRT inspired by a company I’ve worked with.

Current Reality Tree

Current Reality Tree

There is no  obvious V shape and one barely recognizable node where the unique cause of all evil resides, a core problem. It is entity 180 stating “Our offering is only commodity” that is common to the 3 branches of the tree. Offering only “commodity” is probably a critical root cause. Indeed, in this case, all UDEs can be linked to the fact that over time, this company let its leadership slip away and now is facing tough competition only  with commonplace products.

Red arrows are so-called Negative Reinforcing Loops. They negatively amplify, reinforce, an effect.

You may like to watch the video tutorial made with this case.

As margins plummet, means for new developments are scarce and the fear of competition leads the company to follow the leader, reinforcing its commonplace products offers.

Besides, having no clear company strategy, managers define themselves objectives without any alignment, which leads to conflicting objectives and many wastes in operations (Negative Reinforcing loop).

If the company manages to get out of commonplace products and regain leadership, all the UDEs should disappear.


Please consider this post only as a brief introduction to Current Reality Tree. It takes some know-how and experience to be able to build a sound and robust CRT.

Other examples:


Advertisements in this post are not under my control. I don’t endorse nor have any vested interest in those offers.

About the author, Chris HOHMANN

About the author, Chris HOHMANN

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8 thoughts on “Thinking Processes – Current Reality Tree

  1. Pingback: Thinking Processes - Current Reality Tree | The...

  2. Great summary Christ thanks!

    Can you recommend a particular resource/book for applying TOC Thinking Processes to someone’s personal life / small business?

    Alot of the material out there seems fairly heavy. 400-page books full of technical terms and/or expensive seminars… but the root thinking processes don’t sound that complicted.

    Is there a good book or summary somewhere that an individual could pick up and run with, applying the Thinking Processes to solve problems in ther life / biz?


    • Well, I would only recommend two books: Bill Dettmer’s “Logical Thinking Process”, which is big and somewhat expensive, but the best value/price ratio.
      Second would be Lisa Scheinkopf’s “Thinking for a Change: Putting the TOC Thinking Processes to Use”, slimmer, almost as expensive and least going in the step-by-step process for implementation. Lots of personal life examples though. Otherwise you can sift out explanations on the web, for free.


      • Thanks very much Chris. I appreciate the swift reply, and I’m eager to try out these tools. Will check out the books.

        Been looking for non-linear, holistic, systems-based problem solving for a while now — it just seems to make so much sense for messy, interconnected reality. Was excited to find TOC, and now your blog.



  3. CRT seems a a quite good alternative to other methodologies for identifying root causes such as e.g. the 5why’s, Ishikawa or ARCA.
    At least I thought so going through all the articles on the web and from your site, until I reached the end of this article. That example you show is more confusing than actually explaining, at least to me. According to your previous explanation, at the start of the arrows are the causes, and at the end the effects, that would indicate, that following the arrows, I would be able to identify the undesired effects experienced. But your example
    a) indicates, following your arrow logic, that 100, 300, 210 and 200 would be the UDE (thats where the arrows point to), and
    b) has 2 major loops in it where UDE’s (210, 240) going all he way back down again, and
    c) indicates, following your arrow logic, that 130 would be the root cause (because that’s the only place where an arrow starts without having one pointed into…

    So either
    – the explanation of CRT is incorrect, or
    – the example is incorrect, or
    – I’m not smart enough to understand this concept, or
    – CRT works in theory, but is simply to complex to be applied in real life by real people

    So some clarification regarding the presented example would be helpful. The description has raised some hope for an alternative method for RCA, so I don’t wanna trash CRT right now for that purpose. But if I as quality manager don’t understand it, who should that be understood in a community which are focused on other topics (like selling, delivering etc.) and not familiar with problem solving methodologies?

    Thanks in advance.


    • Thank you Tom for extensively sharing your (puzzled) thoughts about the CRT example.

      First a word about UnDesirable Effects (UDEs): UDEs were initially defined as anything “we” don’t like, latter refined (especially with Bill Dettmer’s work) as something preventing the system achieving its Goal or limiting the system’s performance. To qualify as UDE it must hurt the system as a whole. For more about UDEs on this blog:

      In our example, the entities 100 and 300 qualify as UDEs.

      Entities 200 and 210 are steps that trigger and feed the Negative Reinforcing Loops, not UDEs.

      Entity 130 can be regarded as a root cause following the standard definition of a root cause i.e. the lowest cause in the cause-and-effect chain.
      But my article refers to “Critical Root Cause”, a distinction that points to the lowest cause laying within our sphere of authority, or at least sphere of influence, meaning we can do something about it. Entity 130 (Many competitors have similar offers) is a fact of life laying beyond our control or influence. It cannot be regarded as a Critical Root Cause in Logical Thinking Process parlance.

      I have included entity 130 in order to explain how the fact that “we do not stand out among competitors” combines with “Many competitors have similar offers” to produce the effect “Our offering is only commodity”.

      About the Critical Root Causes, please read:

      I hope these additional explanations will help!

      Don’t be surprised about apparent complexity of the Logical Thinking Process, all students went this way and sometimes I myself must still struggle with some cases.

      I therefore also hope you won’t give up considering the CRT for analyses. Once you’ll get used to it, it proves to be a great tool.

      Greetings from Paris, France.


  4. Pingback: Eight Things You Need to Know About the Theory of Constraints - PM 360 Consulting

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