5-Why（DELPHI）

5-Why Critique Sheet –- For Reviewing Suppliers 5-Why’s as part of the PRR Root Cause Analysis

General Guidelines:

Don’t jump to conclusions!
Be absolutely objective.
Don’t assume the answer is obvious.
If you are not thoroughly familiar with the process yourself, assemble a cross-functional team to complete the analysis.

Step 1: Problem Statement

1. Is the analysis being reported on the problem as the Customer sees it

Step 2: Three Paths (Dimensional, Detection, Systemic)

1. Are there any leaps in logic
2. Is this as far as the Whys lead (Can you still ask one, two, three more why’s)
3. Is there a true cause-and-effect path from beginning to end of each path Is there statistical data/evidence to prove it Can the problem be turned off and on
4. Does the path make sense when read in reverse from cause to cause (e.g.—We did this, so this happened, so this happened, and so on, which resulted in the original problem.)
5. Do the why’s go back to the actual error
6. Does the systemic path tie back to management systems/issues
7. Does the dimensional path ties back to issues such as design, operational, tier-n management, etc…
8. Does the detection path ties back to issues such as protect the customer, control plans, etc…

Step 3: Corrective Actions

1. Does each corrective action address the root cause from a path
2. Is there a separate corrective action for each root cause If not, does it make sense that the corrective action applies to more than one root cause
3. Is each corrective action possible to implement
4. Are there corrective actions that affect the Customer or require customer approval How will they be communicated to the Customer
5. Is there evidence and documentation to support the validity of the corrective actions
6. Are the corrective actions irreversible If not, are there corrective actions in place that address containment

Step 4: Lessons Learned

1. How could this problem have been foreseen
2. How will this information be implemented:

a) on the line or in the plant?
b) at the point of detection?
c) cross-functionally at the Supplier?
d) Other product/plants?

1. Are there lessons learned for the Customer

Step 5: Overall

1. Do there seem to be big holes where ideas, causes, corrective actions, or lessons learned are being avoided Where things are missed or not documented
2. Do the corrective actions address what are the actions the supplier owns
3. How many iterations has the supplier gone through so far in preparing this 5-why (It doesn’t happen on the first try!)
4. Who prepared the 5-why