8D D7: how to prevent recurrence with system changes

D7 asks what stops the same kind of problem from happening again, beyond the one part and line in the complaint. Many 8Ds fill it with “training done” or repeat the D5 action. A reviewer looks for changes to the system: the documents, risk analysis and controls that decide how the next part and the next process are made. Terms and expectations differ by customer, so check their 8D format and supplier manual.

Corrective or preventive? Be precise

Most of D7 is still corrective: updating the FMEA, control plan and work instructions for the process that failed acts on a problem that already happened. Only the read-across to similar products and processes that haven’t failed yet is preventive in the strict sense. Labelling it that way shows the reviewer you understand the difference. For the wider terminology, see CAPA vs 8D .

Checklist: what D7 should show

• Why the system missed it: was this failure mode and cause in the PFMEA? If yes, why were the occurrence and detection ratings too optimistic, or the controls not effective? If no, why did the FMEA team miss it (scope, lessons learned not used, no similar-part data)? Fix that gap in the FMEA process, not only this row.
• PFMEA updated: the failure mode and the cause found in D4 added or revised, with occurrence (O) and detection (D) ratings re-assessed after the D5 action and the resulting Action Priority (AP, per the AIAG-VDA FMEA Handbook 2019) or RPN, whichever your customer's FMEA method uses. Severity normally stays the same unless the design changes. Give the document number, revision and date.
• Control plan updated: the new or changed check, its method, frequency and reaction plan. If an added D3 check stays, say so; if it ends, say why.
• Standards and work instructions: which instructions, drawings, or setup sheets changed, with revision and date, and how operators were informed.
• Escape side covered: a change to detection, not only to occurrence, if the escape point was part of D4.
• Lessons learned: recorded where the next team will find them, such as a lessons-learned database or design guideline, with a reference.
• Read-across: a list of similar products, lines, tools or plants checked, the result for each, and the action taken where the same risk exists.
• Owner and date for each item, plus evidence it is done, not planned.

How to do the read-across

• Start from the root cause, not the part number: same machine type, same tool design, same material, same supplier, same work step.
• List each candidate and record the result: risk present, not present, or not applicable, with the reason.
• Where the risk is present, apply the action or plan it with a date.
• Include design if the cause was a design or specification gap.

A table of five checked lines with results is stronger than “applied to all similar products”.

Illustrative examples from different sectors

These examples are fictional and only show the structure.

• Automotive machining: PFMEA rev 12 adds tool-wear cause; control plan adds a tool-life counter; read-across to 3 other lines using the same insert, 2 at risk and updated.
• Aerospace: work instruction for torque sequence revised; lessons learned entered; read-across to sister assemblies sharing the fixture.
• Electronics: stencil design rule added to the design guideline; AOI library updated for all boards with the same package.
• Medical: risk file and process FMEA updated; change assessed under the change control procedure; similar molds reviewed.

Where D7 evidence usually comes from

The strongest D7 sections point to records that already exist in the quality system, so the reviewer can see the change is permanent and not only written into the 8D:

• The revised PFMEA and control plan, with revision number, date and the people who reviewed them.
• The document change record or change request for each work instruction, drawing or setup sheet.
• Training or briefing records that name the revised document, not only the topic.
• The lessons-learned entry or design rule, with its reference and where it sits.
• The read-across table, signed off by the owner of each line or product checked.

Attach extracts rather than whole documents: the changed PFMEA rows, the changed control plan line, and the first page of each revised instruction. A reviewer often has many 8Ds to read, so short, specific extracts are easier to check than a long appendix.

Timing: when D7 can be closed

Some D7 items take longer than the 8D deadline, such as a design change or a read-across across several plants. Close what is done, and list the rest with an owner and a planned date. Then update the 8D when each item is complete. An honest open item with a date is usually easier for a customer to accept than a claim that everything is finished. If the due date is close, see missed 8D deadline: what to do.

Common D7 weaknesses

• “Operators retrained” as the only item. See why operator error is not a root cause .
• D7 that repeats D5 word for word.
• Documents named without revision or date.
• Read-across claimed with no list of what was checked.

D7 builds on D6: if the action isn’t verified, updating standards around it is premature. See D6 verification of effectiveness . The free printable 8D / D4 checklist (PDF) covers D1–D8.

FAQ

Is D7 preventive action?

Mostly not. Updating documents for the process that failed is corrective. The read-across to products and processes that haven’t failed yet is the preventive part.

Is training enough for D7?

Rarely on its own. Reviewers usually expect a change to documents, controls or design, with training as support.

What does 8D Gate check?

It gives a pre-send readiness check on the 8D text: an Accept / Conditional / Reject advisory with missing evidence and questions. It isn’t a customer decision. The review tool is v0.1: it reviews English 8D reports, and the interface and report are in English. Templates are also available in German, Czech and Polish.

Free pre-send readiness check

Before the 8D goes out, run the text through the free supplier 8D readiness check.

Get the free 8D / D4 checklist

Keep the one-page version ready for the next complaint. It covers D1–D8 and goes deeper on containment, D4 root cause, and verification.