Root Cause Analysis

[Vishwadeep Khatri 265]

Q2. Root cause analysis is essential to problem-solving. However, there are four possibilities - (you may watch this video to understand more - https://tinyurl.com/ybtjmnof )

 

1. A cause may be necessary but not sufficient for a problem to occur. 
2. A cause may be sufficient but not necessary for a problem to happen. 
3. A cause may be neither sufficient nor necessary for a problem to occur. 
4. A cause may be both sufficient and necessary for a problem to occur. 

 

How should our approach to problem-solving change for each of the above situations? 

 

Note for website visitors - Two questions are asked every week on this platform. One on Tuesday and the other on Friday.

• All questions so far can be seen here - https://www.benchmarksixsigma.com/forum/lean-six-sigma-business-excellence-questions/
• Please visit the forum home page at https://www.benchmarksixsigma.com/forum/ to respond to the latest question open till the next Tuesday/ Friday evening 5 PM as per Indian Standard Time.  
• The best answer is always shown at the top among responses and the author finds honorable mention in our Business Excellence dictionary at https://www.benchmarksixsigma.com/forum/business-excellence-dictionary-glossary/ along with the related term.  

[Anita Upadhyay 12]

Cause is a variable which affects the outcome by increasing its chances or making it happen.

Problem is the outcome of the cause.

Scenario	Understanding	Conclusion	Action
A cause (X) may be necessary but not sufficient for a problem (Y) to occur.	Problem (Y) occurs ONLY when cause (X) is TRUE Problem (Y) may not occur even when the cause (X) is TRUE	Causes other than X (A, B, …) must occur together with X for problem Y to occur	Fix the cause (X) to remove one of the factors causing the problem (Y) however this will not fix it so look for other causes (A, B, ..) that result in this problem (Y) and address them too to fix the problem (Y).
A cause (X) may be sufficient but not necessary for a problem (Y) to happen.	Problem (Y) occurs whenever cause (X) is TRUE Problem (Y) can occur even when cause (X) is not TRUE	Cause X is a definite cause for the problem (Y), however other causes (A, B, … ) can also result in this problem (Y)	Fix the cause (X) to address some scenarios in which the problem (Y) occurs. However look for other causes (A, B, ..) which may also result in this problem to fix it for all scenarios.
A cause (X) may be neither sufficient nor necessary for a problem (Y) to occur.	Problem (Y) may not occur even when cause (X) is TRUE Problem (Y) can occur even when cause (X) is not TRUE	Cause X is not established as a reason for the problem (Y)	Fixing cause (X) may not fix the problem (Y). Look for other causes (A, B, ..) which are likely to be more relevant cause for this problem (Y)
A cause may be both sufficient and necessary for a problem to occur.	Problem (Y) occurs ONLY when cause (X) is TRUE Problem (Y) occurs whenever cause (X) is TRUE	Cause X is a definite cause for problem Y	Fixing cause (X) may fix Y completely.

[R Rajesh 40]

Generic Definition:

 

Necessary means something needed.
Sufficiency - an amount of something that is enough for a particular purpose

 

1). A cause may be necessary but not sufficient for a problem to occur:
  This means that the problem did/do not arise because of a single cause. There could be multiple causes which could lead to the problem

   

    Eg: An Application running in the system is responding very slowly. We could think that it could be due to less memory space in hard disk/RAM . But it may not be the only reason.
    It could be due to too many applications opened up thereby busying the CPU. It could also be because of some heavy processes running in the background or
    any other reasons.

  

  So our approach should be:

      a). To find out what other causes could be there which can make the problem to occur.
      b). Do try to drill down with 5-Why analysis or tree analysis of the problem or make Fishbone analysis and find out the other causes/category of causes.

 

2). A cause may be sufficient but not necessary for a problem to happen:
    This implies that a particular cause can be a potential source for the problem to occur but not necessarily be the primary one  which will create the problem.
    

    Eg: If System "Welcome Screen" (logging in) taking time is a problem, then increasing the RAM size may be useful but it may not  necessarily be increasing the speed as still the  

           Processor CPU/Processor Speed(Frequency) could need to be addressed. There could be some more ways  which can make this speed increased to
        
    Our approach should be :
      a). Find out the ways to have necessary conditions and satisfy sufficiency
              
3). A cause may be neither sufficient nor necessary for a problem to occur    
      This portrays the fact that you are aware of the causes and have sufficient and needed information to resolve.But still there is a better workaround to ensure that problem does not

      occur
      

      Eg: You/Your organisation has technical challenge on Non Functional requirements and you think you know the causes and has sufficient and needed knowledge. However It will take 2 

      months of time for your team to complete this . But management outsources this to expedite this activity.
          
      So the approach should be
       a). To make effective use of the alternative method/approach that is being planned out for the problem.
         
4). A cause may be both sufficient and necessary for a problem to occur  
    This means that initial assumptions are made on the necessity and sufficiency of causes, for a problem.
    

    Eg: If the problem is the smelling(bad odour) of Septic tank of the house, then immediately the assumption is made that the tank could be full and hence the smell is arising.     
     

    So our approach would be :
       a). To validate as much as you can to ensure that the assumptions made are true. If not, then course correction needs to be done
       b). Depending on the assumptions , we need to proceed. If assumptions are false, then follow one of the approaches from the remaining 3 options/conditions 

[Yogesh. 1]

Q2. Root cause analysis is essential to problem-solving. However, there are four possibilities - (you may watch this video to understand more - https://tinyurl.com/ybtjmnof )

1. A cause may be necessary but not sufficient for a problem to occur. 
2. A cause may be sufficient but not necessary for a problem to happen. 
3. A cause may be neither sufficient nor necessary for a problem to occur. 
4. A cause may be both sufficient and necessary for a problem to occur. 

How should our approach to problem-solving change for each of the above situations? 

 

Root Cause Analysis is to identify the all the factors & find a co-relation between them to provide a corrective action to either eliminate or reduce the risk of occurence of a defined problem.

Steps for Root Cause Analysis:

1.       Define the problem or the objective

2.       Gather data & evidence of the occurrence

3.       Identify the factors & classify the factors as critical & non-critical factors

4.       Generate a theory to co-relate identified factors for the occurrence of the problem

5.       Verify/Validate the theory (may identify multiple critical factors for the problem)

6.       Provide the final solution

 

The approach for problem solving may change for each situation:

 

1.       A cause may be necessary but not sufficient for a problem to occur

Approach:

a.      Re-visit Assumptions

b.      gather more information & investigate further to identify existence of multiple factors which increases the risk of occurrence of the problem

c.       Re-validate to find a correlation with new factors identified to provide solution

 

2.       A cause may be sufficient but not necessary for a problem to happen

Approach:

a.      May be there are multiple ways to provide a solution to the problem.

b.      Identify the easy way, minimum risk or cost effective solution to implement the solution after alignment of stake holders

 

3.       A cause may be neither sufficient nor necessary for a problem to occur

Approach:

a.      re-visit the assumption,

b.       gather more information & re-classify the critical & non-critical factors

c.       Further investigate  is required to identify existence of multiple factors which increases the risk of occurrence of the problem & eliminated not necessary factors

d.      Re-validate to find a correlation with new critical factors identified & eliminated factors to provide solution

 

4.       A cause may be both sufficient and necessary for a problem to occur

Approach:

a.       Confirm  assumption,

b.        Validate the  correlation of all the factors &  provide solution

[Srinivasa Vasu 5]

Root cause analysis: 

It is typically a very effective technique to identify the root causes for a problem or an issue. 

 

This technique uses the approach of right questioning such as WHYs. 

In order to do this analysis, it is also important to clearly identify the problems or issues for which we are going to identify the root causes.

 

considering 4 possibilities: (as per the question)

Example;

Problem: campus placement did not happen,    

 

1. A College could be the cause, but this is not sufficient. It can also be that the job market is also not good for being placed.

 

2. College could be sufficient cause, but not necessary. If the student would have put right efforts, he would have been still placed.

 

3. College may not be the reason at all, it could be the market and insufficient efforts by the students could be the main cause for no placement 

 

4. The college could be the main cause as it doesn't call any companies to come for campus placements. 

 

In such cases and scenarios, Root cause analysis helps to find the right cause.

 

 

 

[Shailesh_Chavan 3]

	Means	Approach for problem solving
Case 1 A cause may be necessary but not sufficient for a problem to occur.	- This cause is must for problem to occur but cannot cause the problem alone. - There will be additional cause/s which are necessary & interaction of these causes becoming sufficient for problem to occur.	- Find out other cause/s which are necessary for problem to occur. - Check which cause out of these is easy to eliminate & improvement made is easy to sustain. - Eliminate that cause to solve the problem.
Case 2 A cause may be sufficient but not necessary for a problem to happen	- This cause can alone cause the problem to occur - But there may be other cause/s also which can cause the problem to occur even in the absence of mentioned cause	- Find out other cause/s which are sufficient for problem to occur. - Find out which cause is creating the problem most. - Start working on that cause. After eliminating the first one take next cause which causes the problem most & so on….
Case 3 A cause may be neither sufficient nor necessary for a problem to occur	This cause is not the main cause for problem to occur	- Find out the cause/s which are  necessary for problem to occur. - If there is only one cause eliminating it will solve the problem. - If there are more than one necessary causes use approach mentioned for CASE 1. - If there is no necessary cause, find out significant cause/s & use approach mentioned for CASE 2 - If there is no significant cause also check interactions of probable causes & find out which interactions become significant. Then try to eliminate the easy to eliminate causes from each of these interactions to solve the problem.
Case 4 A cause may be both sufficient and necessary for a problem to occur.	- This is the main root cause for the problem. - There may be other root causes which are necessary for problem to occur but they will not able to cause the problem in the absence of this cause.	- Eliminate this cause to solve the problem.

[Rupinder N 31]

Necessary - X is a must for Y to occur. Y cannot occur unless X is present.

Sufficient - X is enough to cause Y. However, Z may also cause Y.

 

Scenario 1 - Cause is necessary but not sufficient. X occured at some time for Y to have occured but alongside other factors. In this case, other causes that could have caused Y when combined X have to be found. E.g. there was a case of cars catching fire if hit from behind when the right indicator was on. Having the right indicator on was necessary but not sufficient for a car to catch fire. It had to be combined with the other factor of being hit from behind in order for it to catch fire. Hence, we are looking for critical combinations of other causes with this X.

 

2. Cause is sufficient but not necessary - means that X on it's own can cause Y. But this is not the only cause leading to Y. It is required in this case to make sure that other causes are also found out, else the problem may remain unresolved even when X is fixed. E.g. not having enough water in a day can cause headaches. But so can not eating on time. Even if you keep having water, but not having food could.still trigger the headaches.

 

3. Neither sufficient nor necessary - Even if X happens, Y will not occur. In this case this cannot.be deemed as a root cause. Solving for this X will be futile. Other causes ought to be explored in order for the problem to be solved. E.g. an executive assistant not having an app for calling a cab for her boss is neither a reason sufficient to not get a cab, nor is it necessary. A cab can still be called via a phone call, by asking someone else to order, or booked through a website, by hailing from the street.

 

4. Both sufficient and necessary - must be solved for as whenever X occurs Y will occur. If this is not solved, you have not resolved the problem

 

[Mona Bhandari 0]

RAGIN QUALITATIVE COMPARATIVE ANALYSIS (QCA) is the approach for conducting translactional and implementation research limited by small number of cases.

Secondly; it brings out both qualitative and quantitative data derived from cases to identify the necessary and sufficient conditions for an outcome.

The approach that best fits for all the conditions mentioned above is QCA.

[Anjana Singh 0]

1. A cause may be necessary but not sufficient for a problem to occur. 
2. A cause may be sufficient but not necessary for a problem to happen. 
3. A cause may be neither sufficient nor necessary for a problem to occur. 
4. A cause may be both sufficient and necessary for a problem to occur. 

Necessary & Sufficient Conditions- Firstly condition means causes or reasons to make one thing happen so that the other thing may move. Example to fill a glass of water I would need to open the tap. So the condition is that I need to open the tap then only the water will fill the glass

Necessary – means that without the necessary condition nothing will happen hence necessary condition is require for the next move to happen

Sufficient – means that the condition is enough or not enough for the action to happen.

Example to explain the above 2 conditions:-

To ensure no call drops to a subscriber, we need to have sufficient BTS towers, however BTS towers are necessary for Calls to route and latch on.

1. A cause may be necessary but not sufficient for a problem to occur. 

Example – BTS tower may be necessary but not sufficient to resolve call drop problem.

Approach to problem solving – Do detail study of the no. of complaints coming to call center pertaining to call drop. Analyses the data. Analyze the time and location of maximum call drops.

Initiate with 5 why analysis to come to the root cause of the call drop. While conducting 5 why there can be various factors for call drop.

Then with cause and effect will zero down on a major cause and initiate improvement project.

2. A cause may be sufficient but not necessary for a problem to happen. 

Example -Fuel is sufficient to make an internal combustion engine run, there are times when running the car can be a problem though the fuel is sufficient,  then we look for other various cases, like battery, gear box, radiator heating/leaking, etc…

3. A cause may be neither sufficient nor necessary for a problem to occur. 

Example – For a person suffering with fever, not necessary that the person has fever due to getting wet in the rain, though this can be a reason, but not sufficient. There can be other factors like eating street food during monsoon, which is highly infectious and unhygienic, getting infection from other fellow colleague at work place / school.

In such scenarios, C&E & 5why will or may help us with some root cause, however further analysis like – hypothesis testing etc, will help us arrive to appropriate root cause

4. A cause may be both sufficient and necessary for a problem to occur. 

Most ideal state wherein cause is sufficient and necessary for a problem to occur. Example – A man being a father is both a necessary and a sufficient condition for his being a male parent

Similar – Lack of BTS towers and multiple telecom players latching to the same BTS tower at peak time (9am to 1pm), cheap tariff plan to attract more customers hence choking the bandwidth ,etc  are both sufficient and necessary condition for call drops to happen.

[Nagraj Bhat 10]

Hi All

Here is what I interpret of the topic.

 

For an investigation which is aimed at reaching an argument/observation should have this flow

 

• Appropriate data collection  [ ACCURATE and PRECISE ]
• Followed by the information derived from it  [SIGNIFICANT and RELEVANT]
• The knowledge extracted of it  [NECESSARY and SUFFICIENT]
• Finally wisdom attained  [ WHY/WHY NOT and IS/IS NOT ]

 

Necessary - Lets say it as "a must" condition and Sufficient - is a "good enough" state. 

In order to attain quality  - Reduction of variation is NECESSARY and the SUFFICIENT condition which convinces us that we are on right track is adoption of identifying and tackling 7+1 wastes. Hence an effort has to be both necessary and sufficient ( Provided that the system is robust { insensitive to violations of assumptions}). Compiling both sort of conditions and their impact on corresponding negligence should be carried out with utmost criticality.

 

Extending the discussion onto the RCA/Problem solving domain - I better be sure of my analysis and various components of my synthesis to be

• Mutually Exclusive
• Collective Exhaustive
• with Acknowledged Assumptions.

 

For these cases

 

1. A cause may be necessary but not sufficient for a problem to occur  -  Chase it and dissect further
2. A cause may be sufficient but not necessary for a problem to happen - Dont just ignore it. Assumptions are costly.
3. A cause may be neither sufficient nor necessary for a problem to occur - Why is it in the list. Can I reverse think of it and check if its needed for my analysis
4. A cause may be both sufficient and necessary for a problem to occur - Hmmm... does it talk. Am I listening. Is it a decoy.

 

Regards

Nagraj Bhat ( on behalf of Igniting Minds 95)

[Deepti Arora 2]

A cause may be necessary but not sufficient for a problem to occur

To me the above statement means that a problem can occur due to numerous causes (parts) but it doesnt imply that if the parts dont function properly the problem will always arise.

This to me indicate that the root cause of the problem is something else and the respective cause is not significant enough to cause the particular problem.  In my view under such circumstances, our effort should be directed to first identify the main cause of the problem and then design a solution around it.

 

A cause may be sufficient but not necessary for a problem to happen. 

The above statement to me means that problem can happen due to numerous causes. While some of these will be identifiable and within our control, but there can be causes which are outside our control. In such cases, we cant do much to resolve the issue.

 

A cause may be neither sufficient nor necessary for a problem to occur.

The above statement to me means that problem can happen due to numerous causes. While some of these will be identifiable and within our control, but there can be causes which are outside our control. In such cases, we can just be more prepared and alert to address the issue and prevent it from recurring.

 

A cause may be both sufficient and necessary for a problem to occur.

To me the above statement means that for a problem to occur, a cause needs to be present and at the same time this cause should be significant enough to cause the problem. Such are mostly cases where we have done RCA and know the significance and impact of the cause on the problem. The only way to address issues where the above situation arises would be to let the processes not deviate from the control limits.

 

 

 

[Club 41 0]

A cause may be necessary but not sufficient for a problem to occur.

[Kanwaljit Singh Bhambrah 0]

Root Cause Analysis means conducting a deepdive on a problem to reach the source of problem i order to fix it and permanently eliminate the problem l. Quite often people confuse a symptom to be a root cause. A will have a solution, but symptom will give rise to a problem.

There are many tools to conduct root cause analysis, the common one is 5Why analysis it can be used when there's one factor causing the problem and for multiple factors to be considered for investigation, one can use Cause & Effect diagram aka Ishikawa.

[Mr. Abhijeet 2]

Root cause analysis is an essential way of problem solving. Apart from organization it is a tool  which we can use in our day to day life for problem solving 

Proper root cause analysis methods goes in depth of the problem and gives out several probable causes. These probable causes are of different aspects.

Some cause may be essential but may not be sufficient to contribute to the problem. Likewise some causes are not essential but it may contribute to the problem. Some may or may not be directly involve in  the problem. 

So to know the exact root cause there are some more techiques. To be precise one can always compile  up the probable causes and undergo simulation to reproduce similar problem which will validate the cause as the actual root cause. 

 

There are tools and techniques to carry out root cause analysis

i) Why - Why analysis

ii) brainstorming 

III) fishbone diagram 

iv) pareto analysis etc.

 

These techniques helps to carry out root cause analysis in a systematic and easy way. Through root cause analysis we can prevent further similar issues in future. 

Hence root cause analysis is always the effective way for problem solving. 

[RaghavendraRao 1]

In case of "cause may be necessary but not sufficient", focus should be to confirm the necessity of the cause in hand and also explore other causes which suffices the condition needed for the problem to occur.  

In case of "Cause may be sufficient but not necessary for problem to happen", it need to be treated as a unique and special cause and needs for attention and investigation to understand nature of the cause and its impact. 

In case of "cause may be neither sufficient nor necessary for problem to happen", exploration to be done for those causes that suffices the condition for problem to happen, exploring real causes of the problem. 

In case of "cause may be both sufficient and necessary for a problem", it is ideal situation which exposes all possible key causes for problem and all causes need to be addressed as part of problem solving.

[Vastupal Vashisth 34]

Root Cause Analysis is for a problem solving. approach to be follow according to four possibilities:

• A cause may be necessary but not sufficient for a problem to occur. 

for example customer found a wrong Door assembled in a car because a wrong variant part has been assembled to another child part in welding jig. in this, wrong variant part supplied and welded with child part in welding jig is necessary cause for wrong assembly but not sufficient because system is not so effective that it can stop assembly of wrong variant parts to child parts and stop delivery of those wrong assembled door in car. we can do why why analysis/brainstorming and can do Poka-Yoke to error proof so that wrong variant will not be assemble with child part in welding jig so that it customer will not get wrong assembled door in the car.

 

• A cause may be sufficient but not necessary for a problem to happen. 

let me tell you this with a example, if a part is rejected then to have crack in part is sufficient to reject it but its not necessary to have only crack because there are other factors also due to which part can be rejected. So in this case we can use Why Why analysis to find out root cause.

 

• A cause may be neither sufficient nor necessary for a problem to occur. 

For example we have rejection of different parts due to different factors because one cause is neither sufficient nor necessary, so we should do initially brainstorming, affinity diagram followed by  Pareto Analysis for prioritization and then do why why and fishbone analysis accordingly

 

• A cause may be both sufficient and necessary for a problem to occur. 

Parts not delivered to next customer because of non availability of parts due to non production that is sufficient and necessary condition. in this case we can for JDI( just do it), we can produce the parts and can deliver the parts to next customer because we know both cause and solution.

[Anupama 3]

Root cause analysis is a reactive method and not a proactive method for problem-solving.  The problem is being analyzed to find the cause.  Four different situations: In the first case…

 

1. A cause may be necessary but not sufficient for a problem to occur –The term “necessary” is an important condition.  Eg. Money is necessary but not sufficient to be considered as a rich person if taxes are paid in full.

 

2. A cause may be sufficient but not necessary for a problem to happen. – The term “sufficient but not necessary” is underlined.  Sufficient bank balance to be considered as rich, but not necessary to be a problem if it’s well managed.

 

3. A cause may be neither sufficient nor necessary for a problem to occur

Money might not be sufficient or necessary for the Health problems to occur.

 

4. A cause may be both sufficient and necessary for a problem to occur.

If taxes are not paid, money can be both sufficient and necessary for a problem to occur

[Arunesh Ramalingam 15]

Necessary Condition:

• Result is TRUE ONLY IF Cause is TRUE. (Or)
• Result ONLY IF Cause (Or)
• In Absence of Cause, Result does not occur.

Sufficient Condition:

• IF Cause is TRUE, Then Result is TRUE. (Or)
• IF Cause THEN Result (Or)
• Presence of Cause ensures Result.

(E.g.) Boiling an Egg cooks it so it is Sufficient Cause but boiling is not necessary cause for cooking because there are others ways of cooking it without boiling.

An interesting Statement:  Root Cause Analysis is necessary, but not sufficient, to ensure that more effective problem solving practices are implemented. [1]

 

(1)    Necessary but not Sufficient (depicted by NnS):

It should be investigated what other “necessary but not sufficient” (NnS) causes exist. A number of NnS causes could supplement each other satisfying the Sufficiency requirement for a problem to occur. If even one of the NnS is removed then the occurrence of the result can be prevented.

(E.g.[3] for an object to be a square it has 4 NnS conditions – should be plane figure, have 4 sides, all 4 sides should be equal, and 4 right angles. If even one of the 4 NnS conditions is removed the object is not a square any more i.e. result loses its validity.)

 

(2)    Sufficient but not Necessary (depicted by SnN):

The only option is to remove the sufficient causes so that the occurrence of the result can be prevented.

 

(3)    Neither Sufficient nor Necessary (depicted by nSnN):

Most of the time these causes can be lived with and can be removed based on the cost involved in working on them. 

It should be analyzed whether it is really worth to invest cost (Time, Man, Money and Resources to remove this and if the result justifies the invest (ROI Analysis)

 

(4)    Both Sufficient and Necessary (depicted by SN)

When a condition is termed as “NECESSARY and SUFFICIENT” then there are always some background assumptions made.

The assumptions should be validated to ensure the sufficiency condition is always True. If YES then these should be prioritized and removed.

Removal of these can also prevent some of the other NnS conditions from becoming sufficient conditions.

 

Causes to Problems can be categorized into 3 types [2]:

1.      Physical Causes which are tangible causes e.g. bearing size

2.      Human Causes which would trigger a physical Cause. e.g. improper mounting or lubricating the bearing

3.      Latent Causes (or Organizational causes): e.g. no system in place to ensure bearing is lubricated when lubricator is on leave.

 

It is hyper critical that an unbiased analysis is done on the 3 categories of Causes to differentiate between the Necessary Vs. Sufficient reasons to identify the root cause for solving the problem.  Domain experts are sometimes biased to address causes related to their area of expertise e.g.  Reliability Engineers might focus almost exclusively on addressing the Physical Causes of problems, whereas sustainable solutions are those that address the Latent Causes of problems [2]. The experts should be used to analyze the problems in their particular area of expertise.

 

An effective implementation of Root Cause Analysis within organizations can be achieved by [1]:

• Empowering the workforce to solve problems within their area of operations,
• Encourage the use of team based problem-solving approaches for more complex problems.

It is advisable to involve a skilled facilitator to ensure that sufficient depth of analysis is conducted in an unbiased way.

 

REFERENCES:

 

[1] http://www.plant-maintenance.com/articles/Getting_Root_Cause_Analysis_to_Work_for_You.pdf

[2] R J Latino and K C Latino, “Root Cause Analysis – Improving Performance for Bottom Line Results”, CRC Press, pp 87-88 (1999)

[3] https://www.khanacademy.org/partner-content/wi-phi/wiphi-critical-thinking/wiphi-fundamentals/v/more-about-necessary-and-sufficient-conditions

 

[Sandeep Rai 0]

The first 3 possibilities are related to casual factors effecting the result. Which means, working on these casual factors or causes may not actually resolve the problem. For a perfect Root-Cause-Analysis, the identified Cause should be both Sufficient and Necessary 

[yours_thina 0]

For any problem to occur at least one cause should be there and necessary. So I ignore all other three points except “A cause may be both sufficient and necessary for a problem to occur”.

The best tool for root cause analysis is the Ishikawa diagram to map all the causes.  And we have Pareto Chart and 5Whys to move towards the causes and to decide the issues to be taken care first. 

Next steps (PDCA):
•    Implementing the suggested action plan to nullify the error %. 
•    Collecting another set of data to understand the improvement status. 
•    If the data shows negative results, changing the action plan

 

FMEA and Kaizen will also help in minimising the need of RCA in future.

[SandhyaKamath 0]

In any organization numerous problems exist in all facets of its activities. The efficiency and survival of the organization depends on how promptly these problems are recognized and their root causes are isolated and eliminated. A systematic analysis of each potential problem area should be carried out to recognize the root causes that are responsible for creating the problem.   Such analysis is called Root Cause Analysis.

A cause may be sufficient but may not be necessary for a problem to occur. If the cause is rectified then the problem will be solved.

[Namrata Mathur 3]

Despite being the fact, the cause is necessary or sufficient, both or either one, the approach to solve the problem should be analytical and conceptual. Important is to make a process-problem and error free:

 

One should be able to:

• Evaluate the situation
• Break them down to understand key components 
• Consider ways of approaching and resolving them
• Choose the most appropriate of these ways to resolve it. 

[Venugopal R 63]

1. A cause may be necessary but not sufficient for a problem to occur

 

This is a situation that crops up for most problems, where we quickly and certainly identify certain conditions, situations or factors that have been prevalent, without which the problem could never have happened. A popular example is when a change is implemented in a product and it fails after deployment, one of the obvious and necessary condition is that there has been an inadequacy in the testing / approval process, though that by itself could not have caused the problem. In short, any lapse in a failure containment system is always necessary but not sufficient reason for a failure. More examples are possible. In such situations, one of the immediate reaction is to fix the identified ""necessary" condition to help arrest or contain further occurrences, until we proceed and figure out the other causes.

 

2. A cause may be sufficient but not necessary for a problem to happen

 

This represents a situation where multiple, possibly independent causes exist. For example, being absent is sufficient to fail in an examination, but not necessary. However, being present for the exam is a necessary condition to pass the exam, but not sufficient.The problem with dealing with causes that are sufficient for the failure, is our ability to pre-identify all such potential causes exhaustively. Ideally we should prevent all such causes, and the degree of exhaustiveness with which we do so, will result in the degree of non-failure. Goes without saying the if such a situation occurs, it has to be addressed and the learning used in strengthening the related FMEA.

 

3. A cause may be neither sufficient nor necessary for a problem to occur. 

 

Most of us will be familiar in the use of Brain storming and the Fish-Bone diagram. Once we list down a list of causes through brainstorming, we try to start narrowing down to potential ones and then the most probable ones. Those causes that are identified as "not necessary and sufficient" tend to get eliminated to help get closer to the actual cause. However, even if an individual cause may be insufficient to cause a problem, it has to be seen if it becomes a threat when combined with other cause(s).

 

4.  A cause may be both sufficient and necessary for a problem to occur. 

 

Whenever we consider a cause to be necessary and sufficient for a problem, we tend to make several involuntary assumptions. For example, if a person has to get an electric shock upon touching a metal surface of an appliance, it is necessary that there must be a current leakage. However a combination of current leakage and earthing failure makes it sufficient for providing an electric shock. (We are assuming many things, for example, no lightning should have struck the appliance when the person touched it!) If we look at it the other way, it is sufficient to have a reliable earthing on the appliance to avoid getting an electric shock. It is often difficult to relate one cause as sufficient and necessary for a problem. It is more common to associate it with a set of causes.

[NiketKumarPhuria 2]

Please see the answer from the Club 57 as follows:

 

I think the answer should be option 1: because the Root Cause Analysis is done to understand what, why and how to solve the problem occurred. Hence, A cause may be necessary but not sufficient for a problem to occur.

 

Root cause can help and detect issues in the current problem and at the same time it will also help in identifying actions for preventing reoccurrence .

 

 

[Amit Simon 2]

1. A cause may be necessary but not sufficient for a problem to occur. 

• Meaning: Along with this there are more causes making this problem happen
• Action: Identify all other causes to satisfy "sufficient" condition.

 

2. A cause may be sufficient but not necessary for a problem to happen. 

• Meaning: Apart from this there are other independent causes making this problem happen
• Action: Identify all causes to satisfy "necessary" condition

 

3. A cause may be neither sufficient nor necessary for a problem to occur. 

• Meaning: Along with this there are both dependent and independent causes making the problem occur
• Action: Identify all causes to satisfy both "necessary" and "sufficient" condition

 

4. A cause may be both sufficient and necessary for a problem to occur.

• Meaning: This is all that is required to make the problem happen and nothing else
• Action: Straight away to analyze and measuring Xs

[Hari Priya G G 2]

1.   A cause may be necessary but not sufficient for a problem to occur. 

In this case we can decide that this cause is not the reason behind the problem hence we should be analyzing all other causes which are sufficient to bring about the problem.

 

2. A cause may be sufficient but not necessary for a problem to happen. 

in this case after understanding the sufficient cause we should analyze all other necessary causes for the problem from occurring, to prevent the recurrence of the problem from occurring in the future.

 

3. A cause may be neither sufficient nor necessary for a problem to occur. 

even in this above case we should analyse all other possible causes which may bring about the problem.

 

4. A cause may be both sufficient and necessary for a problem to occur.

This causal agent in the above case has to be fixed as this will bring about more problem if not addressed.