Chapter 21: D0–D3: Problem Definition, Team Formation, and Interim Containment

D0 and D1 lay the foundation, but many quality teams rush through them. D0 is the preparation phase: assign a leader, ensure they have access to the nonconformity data, and establish communication channels.

D1 is team formation. This isn't a checkbox. The team should include representation from operations, quality, maintenance (if applicable), product engineering, and process engineering. If the defect touches multiple plants, include cross-site representation.

D2 (problem description) is where most 8Ds begin to fail. We see statements like:

• "Parts are defective."
• "Quality issue detected at receiving."
• "CMM failures reported."

None of these are actionable. Auditors will reject a vague D2. Here's what a defensible problem description looks like:

What auditors look for in D2: Measurable specificity, bounded scope, and traceability to the nonconformity report.

Your D2 must answer these four critical questions:

1. What part number, operation, and time period? "Part No. 45-67-890, Operation 12 (Drilling), serial range 2026-001234 through 2026-001567, produced between January 15–22, 2026."
2. What defect mode and measurement? "Hole position out of tolerance on Feature W (datum to hole distance): spec 50.0 ± 0.3 mm. Found defects ranging 50.8–51.2 mm (all high, all > +0.5 mm)."
3. What is the business impact? "Customer complaint received January 24, 2026. 847 parts shipped; 67 confirmed failures at customer assembly. Estimated rework cost $34,000."
4. How was the defect detected, and when? "Customer 100% incoming inspection (CMM). Root cause: incoming check found defect after assembly operation; parts were integrated into sub-assemblies."

D3 (interim containment) is your immediate safety valve. Containment does not mean finding the root cause or fixing the process. Containment means preventing escape of nonconforming product while you solve the problem. Common containment actions include:

• Sorting/rework at the point of discovery: Hold inventory, perform 100% inspection or CMM, sort good from bad, quarantine bad.
• Upstream detection enhancement: Add an interim inspection or measurement at the operation before customer delivery.
• Process changes to prevent new occurrences: Temporarily adjust machine settings, increase tool inspection frequency, add pre-production validation.

What auditors look for in D3: Evidence that escape points have been identified and addressed.

This is the critical phrase: escape point analysis. For each D3 action, you must answer: *Where should this defect have been caught during our normal process, but wasn't?* Then document what interim detection is now in place.

In the hole position example:

• Escape point 1: Operation 12 drill tooling should have been validated with a first-article inspection before production. New action: Perform tool offset verification and CMM sample of first 5 parts after any tool change.
• Escape point 2: Our process work instruction did not include a feature-specific measurement checkpoint. New action: Add a visual work instruction with go/no-go gauge placement at the workstation.
• Escape point 3: Outgoing 100% inspection was not performed due to pressure to ship. New action: Implement 100% inline CMM for this feature until root cause is eliminated and process capability is re-demonstrated.

Each action should have an owner, a target completion date (usually within 24–48 hours for interim actions), and a verification method. Document everything. Photos of the 100% inspection setup, screenshots of the work instruction revision, training sign-off sheets—auditors will ask to see this.