Solve recurring problems with the 5 Whys

Describe the problem with facts

Write what happened, where, when and how often. "3 of 20 deliveries last week arrived late" is useful, while "logistics is poor" invites argument rather than analysis.

Ask why, using the evidence

Ask why it happened, then ask why again about that answer. Five is a guide rather than a rule, so stop when you reach something you can change. Here is an example.

Problem: The delivery was late
Why?     The goods left the warehouse a day late
Why?     The invoice was not ready when the truck arrived
Why?     Accounts received the order after it was packed
Why?     Sales sends orders to accounts only at the end of the day
Cause:   There is no rule for when an order must reach accounts

Focus on the process, not the person

If your answer is "someone made a mistake", keep asking why the process allowed it. People will be honest only if they know this is not about blame.

Fix the cause and check it worked

Agree one action, one owner and one date. Then check the same measure a few weeks later. If the problem returns, you have not found the real cause yet.

Some problems have several causes. If so, follow each branch separately, as a fishbone diagram does.