5 Whys Analysis - Root cause analysis Tool
What is 5 Why?
" The 5 Why analysis is the initial tool used to determine the root cause of any problem. In 5 Whys analysis, we follow to solve any problem by repeatedly asking the question 'Why' 5 times. You may think Why 5 times? actually five times asking why is a good rule of thumb."
Remember that, 5 Why's is a root cause analysis tool, not a problem solving methodology. The 5 Whys' objective is to provide simple, but effective problem solving approach that will outcome in identifying the true root cause and suitable corrective actions for major quality problems. By the simply asking the question "why" you can bifurcate the symptoms from the cause of a problem to track significant symptoms of problems inline until you get real root cause of problem, because the "5 whys" is a simple tool that can help analyst to identify the root cause of problem.
When to use 5 Why?
- Generally, when any customer complaints received or consist issues in assembling or meet the end application requirements The 5 why technique can we use.
- In some cases, problem and root cause is not apparent in general processes or immediate appearance symptoms of problem, we need to deep investigate in those cases.
- When you want to prevent the problem from re-occurring in the future on the critical stages of production or supporting manufacturing processes.
- In case of any significant delivery incident or quality related issues identified and has occurred and received by internal or external customer.
- When any problem refuse to go away and there are no any significant actions can have resolved it, for over due date.
- The 5 why analysis process is best performing when problems involve human factors or interactions, where you can interact with related peoples to ask questions and state the answer for brainstorming on whole collected information to identify the root cause of problem.
- When any problem appears to be a "repeat issue" for particular department, 5 Why can help to resolved it.
Remember that, you don't want to list so many different reasons; you want to go deep on single reason. if you do the same process over and over, and expect to get different results, it might be time to try another approach. The technique provides a structural framework for team can conduct procedure to handle a more complex problem.
The technique offers some benefits are:
- This is really easy to use in at any level of manufacturing processes by interacting with peoples, which are concern with appropriate issues or identified symptoms of problem.
- You can verify the effectiveness of this methodology by quickly manage separate symptoms of problems from all causes for identify the root cause of particular problem.
- By simple method, you can contribute into decide the connection with various symptoms of causes of problem or various problem causes.
- The 5 why technique is enough flexible, it can be used along with other techniques and merge well to contribute to define and identification of root causes, further it can also work well alone.
The 5 Why method assist to decide the cause effect relationship in failure occurrence and this is very simple way to try solving a stated problem without a statistical, mathematical, stressful investigation requiring many resources. And this is advantage of this technique. We are talking here about benefit so i would like to conclude here as: The 5 Why is beneficial because its (1) Simplicity (2) Effectiveness (3) Flexibility (4) Engagement (5) Inexpensive (6) Comprehensiveness.
How to use 5 Why? - Step by step instructions
As same as other tools and techniques, 5 Why also need to proper planning and preparation by effective team efforts. You have to focus on the problem to identify root cause for perfect corrective actions. The results of a 5 why's analysis is one or several root causes that ultimately identify the reason why a problem was originated. See the picture below, little effort for better understanding:
The 5 why technique use a why table to sequential index the questions and their respective answers. The below table is an example of "5 why" delivered on appropriate issues. How each answer becomes the questions on next stage and each why question uses the previous answer establish clear link between them. Just simple questions and respective answer provides clues to understand, how particular problem occurred and what really needs to positive corrective actions for appropriate issues. So, lets the how we can track failure path by "5 Why" technique from the occurred.
5 why root cause analysis Question: Table
|Why Question||3W 2H Answer (What, When, Where, How & How much)||Evidence||Solution|
|Why[ 1 ] Machine not starting?||Because machine electrical input panel circuit not working.||No power indicates machine's control panel||--|
|Why[ 2 ] Electrical input panel circuit not working?||Because circuit wiring shorted.||Burning signs are found on circuit and connected wires.||Remove burned wire and parts from circuit.|
|Why[ 3 ] circuit and wiring ignite?||Because during the installation, wiring is not properly installed and due to wiring short, circuit parts are also burned.||Wiring diagram not matched with installed wiring on circuit.||Identify which part of circuit and wire will needs to install as right way.|
|Why[ 4 ] Wiring is not properly installed?||On after verification with standard installation guide for input panel, wiring found randomly installed.||Mismatch of physical wiring on circuit with standard installation guide as well wiring diagram.||Re-install all wiring & circuit parts as per standard installation guide.|
|Why[ 5 ] Electrical engineer had mistaken during installation of wiring?||Because he ignored to read and follow standard installation guide and followed old work instruction for installation of input panel.||Old work instruction and standard installation guide for input panel is mismatched.||Update all work instruction on periodic or as on new purchasing, new technology or any other update for instruction of machinery.|
Here as above table is just an example to describe how the "5 why" technique perform in real case, it can possible you can ask more "Why" questions go into deep to identify root cause of problem. Actually "5 why" is standard rule of thumb.
5 why Process - Step by step instruction
- ▽ When I was jointed industrial works, I listen the sentence "Well defined problem is a half resolved problem", hence, it is necessary that try to make you describe state the problem as clearly as possible. State the problem you have identified as a strategic problem to work on. How? here it is answer:
- Write down the specific problem. Description of written the problem will assist you to structure the problem's solution.
- it will help a team to focus on the same issue.
- Try to describe current condition of processes, issues and merge possible related situation in statement.
- Verify and use data information if customer dissatisfaction above unacceptable level.
- ▽ Identify peoples knowledgeable about the area of non-conformance recorded, for build the team to do involve as many personnel as possible. Establish the problem statement with highlight the issues to decide whether or not additional individuals are needed to resolve the problem.
- ▽ On presentation board or on paper, write down a full description of what details collected from non-compliance area. Prepare document the problem and describe it as completely as possible. refine details by discussion with team member to identify possible cause.
- ▽ How to conduct 5 Why Process? - Start asking questions "why-why" related to the problem:
- 1st Why: The first "why" question gives you plainly explanation the reason in short sentence. You have to use the first answer as the foundation of next question, but don't judge it instead of try to understand connection between processes and problem. May be person who is related with area where problem is occurred will gives you many reasons for particular problem, try to filter all those answers by brainstorming at on the stage first "why".
- 2nd Why: As on second stage of "5 Why", you have to go in deep to support the first statement on initial questioner stage's explanation. Try to go in to deep on technical details and verify which symptoms could raise as existing problem, you have to be clear on "know" and "unknown" to target root causes.
- 3rd Why: Do not come on conclusions yet, keep continue regular thought process to follow answer for understand. You have to concentrate on the area where the problem could have been first originated. On the stage of third of 5 Whys' will take you to a deeper comprehension of the problem. You can visualize the regular process map, product cycle and related processes to listing down the most likely sources for the problem to occur. This whole process is part of investigation, hence you have to interact with peoples and go to the processes to see things you could have missed at first.
- 4th Why: Clear your mind from preconceived notions and start the fourth stage with candid approach. You may have more different avenues to explore now, look for systemic causes of the problem and discuss these and settle on the most likely systematic cause. You can use problem solving tool like cause and effect analysis to explore all the included resources and processes like materials, machines, method, etc.
- 5th Why: Now you are on final stage of "5 Why", it is likely that you have get systemic cause hence the problems in the process can be traced on this stage, even related & hidden issues can be show up that is supporting to cause. When you address a systemic cause, do it across the entire process and detect locations that may be under the same situation even if there are no reported problems yet. Once the most probable root cause of the problem identified and confirmed, next step is should establish proper planning for corrective actions to eliminate the root cause from the system.
5 Why Analysis
Initially, you have to confirm that all those potential root causes are under your control by determine and apply some validations to your identified root causes. Ask the questions for every identified answers to identify all the levels of the 5 why as below:
- You should have to proper evidence such as perfect measurements, observation data and related evidences to support this root cause determination.
- Is there any previous experience records or standard guidelines to indicate that the possible root cause could actually produce such a problem?
- Do you identify there anything that as results the possible root? or any evidence that prove these root cause can produce the problem.
- Are there any other reasons that could possibly produce the same problem?
5 Why Filter: Table
|▽ Identify Problem:
|▽ Problem Clarified ( Basic Cause / Effect investigation)|
|▽ Area of cause located ( Where in the process is the problem occuring? )
|▽ Point of cause ( to go in the process to see the problem)|
|▽ First Why
|▽ Second Why|
|▽ Third Why to Continue why? until root cause
|▽ Root cause|
|▽ Corrective actions
The 5 Why methodology is related to the fishbone diagram and can be used to finish the analysis required to complete a cause and effect analysis process.
5 Why Analysis is structural process where you can organize the collected information in proper way and define it in an understandable manner. When the mentioned details cannot give a proper answer required for identify root cause, you have to keep continue for further investigation for identification of meaningful reasons and this is the advantage of "5 Why" analysis process. Remember that, the "5 Why" is not problem solving technique but more of a tool to aid to identify root cause of the defined problem. it will not the resolution of the problem itself, or standalone for elimination of problem, but this tool will more effectively assist in problem solving techniques.
First Published On Date: Monday, September 04, 2017 10:00 AM