|Number of Participants||Facilitators||Category||Duration||Level of Difficulty|
|2 People per Subgroup||1||Ideation Phase||10min||Simple|
Five whys (or 5-Whys) is an iterative interrogative technique used to explore the cause-and-effect relationships underlying a particular problem. The primary goal of the technique is to determine the root cause of a defect or problem by repeating the question “Why?”.
There are two main primary techniques for analysis to be branched in order to provide multiple root cause:The fishbone (or ishikawa diagram). Use 5-Whys in Combination with Fishbone Diagram The 5-Whys can be used individually or as a part of the fishbone (also known as the cause and effect or Ishikawa) diagram. The fishbone diagram helps you explore all potential or real causes that result in a single defect or failure.
The tabular format technique is the one that is most used by individuals when using five whys technique in usability.
- Large sheet of paper (big enough for everyone to stand around)
- Wall or board to put the paper on
- Private and quiet space
- Marker, Pencils
- People should be standing
Always go through a root cause analysis phase of difficult problems — otherwise solutions may be short-lived and unsustainable. Don’t debate each point to death. Identify issues and move onto the next as quickly as possible. It’s important to complete it so you can see the whole picture before drawing conclusions.
- Write down the problem
- Ask why the problem is happening
- Write the answer to the “Why”
- If the answer didn’t identifies root causes start from step 2
Strengths: Simple technique and usable for identifying every problem’s root. Weaknesses: Tendency to stop at symptoms without closing up to root causes of a problem. Knowledge limits the ratio of causes that can be found. Results are not repeatable.
Ohno, Taiichi (1988). Toyota production system: beyond large-scale production.
Portland, OR: Productivity Press. ISBN 0-915299-14-3.
Five why root cause analysis, Available at: https://workshopbank.com/5-whys-rootcause-analysis (Accessed: 13th August 2020).
Bulsuk, Karn. “An Introduction to 5-why”. Retrieved September 5, 2019.
Contributed by Jason Appiah.