Help Manual


Sigma Magic Help Version 15

5 Why Analysis


The 5 Why Analysis can be used to determine the root cause for a problem by repeatedly asking "Why". The purpose of using this analysis is to use a structured approach to arrive at the root cause of the problem so that the problem can be fixed once and for all. It is usually observed that when people talk about a problem, they describe the symptom and not the root cause and directly jump to a solution. Attacking the symptom to solve a problem would not result in a permanent fix of the problem and unless the real root cause is addressed the problem keeps coming back.

To add this tool to your workbook, click on Lean and then select 5 Why Analysis.



A sample screenshot of the setup menu is shown below.
Setup Dialog 1
Analysis Type: Specify the format of the chart. This selection is not enabled since there is only one format available.
Num Whys: Specify how many Why's do you plan to use for your analysis. The number of why's you specify here will impact how the worksheet if formatted. You can always change this number later but ensure you have a sufficient number of why's to start off with. The default value is 5.
Display Elements: You can customize your worksheet by displaying the elements you are interested in. By default, the 5Why worksheet always contains the problem statement row, the root cause row, and the response to the 5Why questions. However, depending on your situation, you may choose to show more information on the worksheet. This will help you guide the discussions within your team to arrive at the right root causes and countermeasures. Select the checkbox for the following items:
CountermeasuresDisplay the countermeasure row on the worksheet. The countermeasure row can be used to document the "solutions" to address the identified root causes.
ImpactDisplay the impact row on the worksheet.
QuestionDisplay the 5Why question in addition to the response column.
EvidenceDisplay what fact or evidence you have collected for each 5Why question.
View Example: Click on this button to open the example file. You can view the example to get an idea of how to fill out this tool or you can use the example as a starting point and modify it to meet your project needs.
Help Button: Click on this button to open the help file on this topic.
Cancel Button: Click on this button to exit without saving any changes.
OK Button: Click on this button to save changes and update your analysis results.
Once the worksheet has been formatted, enter the information on the worksheet as follows:
  • Write down a short one-line description of the problem statement for which you want to perform the 5Why analysis. Make sure that if there are several problems you are working on; each problem will have its 5Why analysis worksheets.
  • The root cause row contains the final root cause of this analysis. Leave this row blank as the software will fill this row for you based on the response to the final 5Why question on your worksheet. Any information you enter on this row will be overwritten by the software.
  • If you have selected to display the countermeasure row, once you have completed the 5Why analysis and determined the root cause, fill out the countermeasure row. The countermeasure could be a combination of both temporary and permanent countermeasures.
  • If you have selected to display the impact row, share the impact of addressing this root cause and the selected solution on the problem statement. For example, this countermeasure will resolve 70% of the problem (or will result in a benefit of $100K).
  • Continue asking why and fill out the above information for each why. Note that there may be more than one cause for a given problem statement. Make sure the causes you enter are validated - in the sense that you should have verified by going to the Gemba that this cause has been observed. For each 5Why block, you need to fill out the following:
  • If you have selected to display the 5Why question, frame the right 5Why question and display the question here. It is recommended that you display the 5Why question clearly so that other participants can review your line of thinking and ensure that you have done the right analysis.
  • Enter the response to the 5Why question in the next row. Make sure that the response is factual and based on the evidence you have collected. Don't guess the probable response here. If there are multiple causes, specify the most important cause or create multiple worksheets for each cause.
  • If you have selected to display the 5Why evidence, share what evidence you have collected to justify the response indicated in the earlier column.
  • Continue asking why until you have reached an actionable root cause that is within your team's control.


If you click on the Checklist button, you will see the following dialog box. Checklist The checklist contains a few pointers on things you need to pay particular attention to while performing this analysis. The checklist has been derived from experience working on past projects. Not all the checklist items need to apply to you. However, you should carefully review the checklist and apply any recommendations that make sense for your project. Make sure to read each checklist item and mark it as completed after you have read and taken actions as appropriate for your project.


If you click on the Verify button, the software will perform some checks on the data you have entered. A sample screenshot of the dialog box is shown in the figure below. Verify The objective of this analysis as well as any checks that are performed is listed in this dialog box. For example, the software may check if you have correctly specified the input options and entered the required data on the worksheet. The results of the analysis checks are listed on the right. If the checks are passed, then they are shown as a green-colored checkmark. If the verification checks fail, then they are shown as a red-colored cross. If the verification checks result in a warning, they are shown in the orange color exclamation mark and finally, any checks that are required to be performed by the user are shown as blue info icons.


Click on Compute Outputs to generate the analysis results. A sample screenshot of the worksheet is shown below. 5 Why Example Based on the options specified on the input dialog box, the software will check if all the required rows of data have been filled out on the worksheet and also if you have answered all the check-box questions in the affirmative. Any errors on your worksheet are displayed on the top of the page and if everything is fine, an OK message is displayed.


Here are a few notes regarding this analysis:
  • You can analyze a maximum of 10 why's using this analysis. If you have several parallel paths for root cause analysis, you can use multiple worksheets to perform the root cause analysis for each path.


Following examples can be found in the Examples folder within the software.
  • Use the 5 Why analysis to determine a potential root cause for the problem of the fuse getting blown very frequently for a given equipment (5 Why Example 1.xlsm)
  • Use the 5 Why analysis to determine the potential root causes for poor product quality. (5 Why Example 2.xlsm)


For more information, refer to the following: