Monthly Archives: September 2011
Root Cause part 2
To continue my previous blog in which I discussed the fact that in many cases there is NOT just a single root cause. There are those that prescribe to the notion that a problem can be turned on and off like a light switch. In some cases this may be the case but every situation is different but there are typically numerous contributing causes that cause a resulting effect (problem).
A camper has accidentally spilled some kerosene while camping. Shortly after a hiker is walking past and smoking a cigarrette in what is labeled a NO SMOKING area. The hiker discards his “butt” on the ground which ignites the surrounding kerosene soaked bush and causes a large fire. Is “the root cause” the “butt” (ignition source) that was discarded from smoking in a banned area (failure to follow the policies), the presence of oxygen (contributing factor), the accidental spilling of kerosene (contributing factor), or other? Without the presence of Oxygen there can be no fire. Is that the cause? No – In theory it can turn the effect on and off though it is not easily controllable. It would keep any fire from starting though. Is the illegal smoker the cause? If he were not disposing of the cigarrette but at that time would the fire have occurred? If the Kerosene had not been spilled would the fire have occurred? (What if another ignition source had come along at that precise time?)
As previously mentioned most root cause analysis comes to an end when the group involved run out of root cause ideas/ questions that are within their control. In this example we cannot control oxygen presence on a large scale, thus that cause would not be addressed. Most likely a means of better controlling the combustible materials and ignition source would be looked at (more policies, signs, etc…).
Let’s look at the “list of root causes” that would typically be suggested/ discussed and evaluated by a group of problem solvers. The list would be confined to the “brain power” of the assembled group. The “brain power” would be defined by their knowledge, experience, education, etc…. It makes sense then, that the larger the pool of potential root causes that are looked at, the more likely that most of the contributing factors and root causes will be evaluated. This is why Group Problem solving is more effective than a single person (more brain power).
Another common problem solving/ root cause analysis tool is the Fishbone or Ishikawa diagram. The benefit of this tool is that it reminds the group of other categories of causes and helps get additional potential causes on the board that may otherwise escape them. Examples are measurement causes, method causes, material causes, manpower causes, environmental causes, machine, etc….
In a nutshell – the more potential causes that you can get out in the open for the group to discuss, the more effective your problem solving effort will be.
Article 3 will get into what are typically called the 3 types of root causes. All three may or may not exist in every situation:
1) Process Root Causes (The controllable event within the process in question) – The ignition source in the above example.
2) Measurement Root causes (Deals with the lack of or ineffective measurement/ monitoring/ detection system to detect the cause or the effect) –
3) System Root Causes (Deals with the systemic issues/ weaknesses that helped lead to the effect being investigated) –
Until next time – Here is to effective problem solving!!!