1. Invite all affected parties to the meeting.
2. Select a meeting leader to lead the discussion.
3. Ask “Why?” five times. Include the previous answer in the question to keep a narrow focus on the problem.
4. Use Who, What, When to assign responsibility for solutions.
An example from Toyota:
“Why did the robot stop?”
The circuit has overloaded, causing a fuse to blow.
“Why is the circuit overloaded?”
There was insufficient lubrication on the bearings, so they locked up.
“Why was there insufficient lubrication on the bearings?”
The oil pump on the robot is not circulating sufficient oil.
“Why is the pump not circulating sufficient oil?”
The pump intake is clogged with metal shavings.
“Why is the intake clogged with metal shavings?”
Because there is no filter on the pump.