Three-Legged Five Why Template for Excel

Performing 3L5W analysis is easy using QI Macros add-in

The three-legged five why (3L5W) template is similar to a fishbone or Ishikawa diagram. However, the 3L5W template puts additional emphasis on testing the logic of your cause and effects analysis. It also distinguishes between three types of failures using the three legs of: specific problem, detection failure and systemic failure.

example of 3 legged five why template

Five why's of root cause analysis: first why happens because of the second why which happens because of the third why.

Test of root cause logic: Third why happens, therefore, the second why happens, therefore, the first why happens.


QI Macros Three-Legged Five Why (3L5W) Template for Excel

QI Macro installs on Excel's menu. To open the template, click on QI Macros » Improvement Tools » 3 Legged 5 Whys.

improvement tools menu

A template with three tabs will open.

template tabs

To complete the analysis, open the worksheet tab labeled 3L5W Outline:

Analysis of the specific problem

  1. Enter the problem statement in Cell B2 for the issue (see below)
  2. Describe the Specific Problem in A2
  3. Ask Five Whys to complete.
  4. Check logic backwards using the therefore statements.
  5. Clear any cells with unused whys.

Analysis of the detection failure

  1. The Root Cause (last why in the list) of the Specific Problem becomes the Detection Failure problem (A6).
  2. Ask Five Whys to find root cause of detection failures.
  3. Check logic backwards using the therefore statements.
  4. Clear any cells with unused whys.

Analysis of the systemic failure

  1. The Root Cause of the Detection Failure becomes the Systemic Failure problem (A10).
  2. Ask Five Whys to find root cause of detection failures.
  3. Check logic backwards using the therefore statements.
  4. Clear any cells with unused whys.

Three-legged 5 Why Outline

Now click on the worksheet tab labeled "3 Legged 5 Whys" to view the results.

Three-legged Five Why 3L5W Template Excel

Complete the remaining sections shaded in yellow. Hover your mouse over cells to bring up instructions.

  • Permanent Corrective Actions
  • Timing for Corrective Actions
  • Read Across Actions
  • Timing for Read Across Actions
  • Lessons Learned Summary

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