Current reality tree (theory of constraints): Difference between revisions

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One of the [[Thinking Processes (Theory of Constraints)|Thinkingthinking Processesprocesses]] in the [[Theorytheory of Constraintsconstraints]], a '''Currentcurrent Realityreality Tree'''tree (CRT)''' is a waytool ofto analyzinganalyze many systemsystems or organizational problems at once. By identifying root causes common to most or all of the problems, thea CRT can greatly aid focused improvement of the system. A current reality tree is a [[directed graph]].

{{context}}<!-- Can the context flag be removed now?-->

One of the [[Thinking Processes (Theory of Constraints)|Thinking Processes]] in the [[Theory of Constraints]], a '''Current Reality Tree''' (CRT) is a way of analyzing many system or organizational problems at once. By identifying root causes common to most or all of the problems, the CRT can greatly aid focused improvement of the system.

==Simplified explanation==

A CRT is a focusing procedure formulated by [[Eliyahu Goldratt]], developer of the theory of constraints. This process is intended to help leaders gain understanding of cause and effect in a situation they want to improve. It treats multiple problems in a system as symptoms arising from one or a few ultimate root causes or systemic core problems. It describes, in a simple visual drawing(cause-and-effect network) diagram, the main perceived symptoms (along with secondary/ or hidden ones that lead up to the perceived symptom(s)symptoms) of a problem scenario and ultimately the apparent root cause(s)causes or core conflict. The benefit of doingbuilding thisa CRT is that it much easier to identifyidentifies the connections or dependencies between theseperceived symptoms (effects) and root causes (core problems or conflicts) explicitly. ThusIf core problems are identified, focusprioritized, canand betackled placedwell, multiple undesirable effects in the system will disappear. Leaders may then focus on solving the bitsfew core problems which would cause the biggest positive changesystemic if tackledchanges.

==Contextual explanation==

A current reality treeCRT is a statement of an underlying core problem and the symptoms that arise from it. It maps out a sequence of cause and effect from the core problem to the symptoms. Most of the symptoms will arise from the one core problem or a core conflict. RemoveRemoving the core problem and we may well be ablelead to removeremoving each of the symptoms as well. Operationally we workworking backwards from the apparent undesirable effects or symptoms to uncover or discover the underlying core cause.<ref name="Dettmer1">Dettmer, H. W., (1997) ''Goldratt's Theory of Constraints: a systems approach to continuous improvement''. ASQC Quality Press, pp. 62–119.

</ref><ref name="Dettmer2">

Dettmer, H. W., (1998) ''Breaking the constraints to world class performance''. ASQ Quality Press, pp. 69–102.

</ref><ref name="Scheinkopf">Scheinkopf, L., (1999) ''Thinking for a change: putting the TOC thinking processes to use''. St Lucie Press/APICS series on constraint management, pp. 143–169.</ref>

==Example==

[[Image:CurrentRealityTree Example.png|thumb|right|Current reality tree example]]

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.

==See also==

*[[Theory of Constraintsconstraints]]

*[[Thinking Processesprocesses (Theorytheory of Constraintsconstraints)]]

*[[Why-because analysis]]

*[[Influence diagrams approach]]

==References==

{{reflist}}

[[Category:Theory of Constraintsconstraints]]