page_title: Current reality tree (theory of constraints)
section_title: Example
hierarchical_section_title: Current reality tree (theory of constraints) / Example
caption_attribution_description: English: Current Reality Tree showing diagnosis of multiple symptoms - or undesired effects (UDEs) - relating to car/automobile problems. Root cause revealed to be faulty handbrake.
context_page_description: One of the thinking processes in the theory of constraints, a current reality tree is a way of analyzing many systems or organizational problems at once. By identifying root causes common to most or all of the problems, a CRT can greatly aid focused improvement of the system. A current reality tree is a directed graph.
context_section_description: A CRT begins with a list of problems, known as undesirable effects (UDEs.) These are assumed to be symptoms of a deeper common cause. To take a somewhat frivolous example, a car owner may have the following UDEs:
  the car's engine will not start
  the air conditioning is not working
  the radio sounds distorted
  The CRT depicts a chain of cause-and-effect reasoning (if, and, then) in graphical form, where ellipses or circles represent an "and". The graphic is constructed by:
  attempting to link any two UDEs using cause-and-effect reasoning. For example, "if the engine needs fuel in order to run and fuel is not getting to the engine, then the car's engine will not start."
  elaborating the reasoning to ensure it is sound and plausible. For example, "if the air intake is full of water then air conditioning is not working." Elaboration (because air is not able to circulate) gets added as in-between step.
  linking each of the remaining UDEs to the existing tree by repeating the previous steps.
  This approach tends to converge on a single root cause. In the illustrated case, the root cause of the above UDEs is seen as being a faulty handbrake.
caption: Current reality tree example
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