Current reality tree (theory of constraints)
One of the 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
This process treats multiple problems as symptoms arising from a few ultimate root causes. It describes, in a simple visual drawing, the main perceived symptoms (along with secondary/hidden ones that lead up to the perceived symptom(s)) of a problem scenario and ultimately the apparent root cause(s) or conflict. The benefit of doing this is that it much easier to identify the connections or dependencies between these. Thus, focus can be placed on the bits which would cause the biggest positive change if tackled.
Contextual explanation
A current reality tree 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. Remove the core problem and we may well be able to remove each of the symptoms as well. Operationally we work backwards from the apparent undesirable effects or symptoms to uncover or discover the underlying core cause.[1] [2] [3]
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 engine won't start
- the air conditioning isn't working
- the car's radio sounds distorted.
The CRT is constructed by:
- attempting to link any two UDEs using a chain of cause-and-effect reasoning
- elaborating the reasoning to ensure it is sound and plausible
- 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. Additional root causes are the proximity of the swimming pool to the parking space and lack of barriers around the pool.
See also
References
- ^ Dettmer, H. W., (1997) Goldratt’s Theory of Constraints: a systems approach to continuous improvement. ASQC Quality Press, pp 62-119.
- ^ Dettmer, H. W., (1998) Breaking the constraints to world class performance. ASQ Quality Press, pp 69-102.
- ^ 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.