Definition
MBS 5WHY summary draft unique negative checklist: six avoidances (excuse inference, subjective psychology, office-based data review, unverified speculation, jumping answers, responsibility shifting), four major misconceptions (attribution difficulty, blaming people, no causality, empiricism), and "because XX, therefore XX" reverse interpretation verification; preceded by 5W2H seven questions, followed by three standard tables. Non-DBS standard.
In detail
The negative checklist turns "non-answers" into decidable types: supplier issues, too many orders, occasional occurrence, industry leader can't do it either, process is just like this, was bad before, no budget—these seven are lazy excuses; not serious, careless, fatigued, new employee are attributed to people; the chain must be readable in reverse; ask from principles rather than experience (for a broken screw, ask about torque limit and hole diameter, not "wind wrench torque is high"). The number of layers is not fixed; each layer must have on-site evidence and data.
Example in practice
5WHY table third level wrote "employee carelessness"; the assistant, per misconception 2, prompts that the focus should be on equipment or management mechanisms; after changing to "missing poka-yoke fixture", it auto-generates the reverse sentence "because the fixture is missing, it can be assembled in reverse, so scratches occur" for the team leader to confirm.