The checklist
Area / line: · Station or process step: · Auditor: · Layer: · Date and shift:
| # | Area | Audit question | Yes | No | N/A | Fixed now or action raised |
|---|---|---|---|---|---|---|
| 1 | Control plan | Is the current control plan revision at the station, and are its checks done at the stated frequency? | ||||
| 2 | Work instructions | Are the work instructions posted, at the current revision, and followed by the operator you observed? | ||||
| 3 | Work instructions | Can the operator explain the key points of the step and why they matter? | ||||
| 4 | Error-proofing | Has each error-proofing device been verified this shift, with the result recorded? | ||||
| 5 | Error-proofing | Is every error-proofing device working, with no bypass or override in place? | ||||
| 6 | Process parameters | Are the critical parameters (temperature, pressure, torque, speed) within the control plan limits? | ||||
| 7 | Gauges | Are gauges and test equipment identified and within their calibration date? | ||||
| 8 | Gauges | Was the start-of-shift or first-off check done and recorded? | ||||
| 9 | PPE and guards | Is the required PPE worn, and are guards and interlocks fitted and working? | ||||
| 10 | Nonconforming product | Is suspect or nonconforming product tagged, segregated and recorded? | ||||
| 11 | Nonconforming product | Does the operator know the reaction plan if a check fails? | ||||
| 12 | Last audit | Have the issues from the last layered process audit at this station been closed, and has the fix held? |
Questions 1–8 and 10–11 come from the control plan and the work instructions for the step. Write them so the auditor has to look: "show me the last torque reading" rather than "are torques checked?".
Who audits at each layer, and how often?
| Layer | Who | Frequency | Stations covered | Time |
|---|---|---|---|---|
| 1 | Team leader or shift supervisor | Every shift or daily | Own area, every critical station in rotation | 10 minutes |
| 2 | Area or production supervisor | Weekly | A sample across the area | 10–15 minutes |
| 3 | Department manager (production, quality, engineering, maintenance) | Monthly or fortnightly | A sample across the department | 15 minutes |
| 4 | Plant or site manager | Monthly or quarterly | A sample across the site | 15–20 minutes |
Higher layers audit fewer stations, but they use the same checklist. That is the point of layering: the plant manager sees the same shop floor reality as the team leader, and team members see that every level of leadership cares about the same standard.
How do you run a layered process audit?
- Go to the station at the scheduled time with the checklist for that step.
- Observe the work before asking anything. Check documents, gauges and devices yourself.
- Mark each question yes, no or not applicable. Add a photo or reading where the question asks for evidence.
- Fix what can be fixed on the spot with the operator, and record what was done.
- Raise an action, with an owner and due date, for every 'no' that cannot be fixed now.
- Thank the operator and tell them what you found, good and bad.
How do you score and follow up?
Score compliance as yes answers divided by yes plus no; leave N/A out. Report it by question as well as in total. A question that fails across several operators and shifts points to a process problem, such as a confusing instruction or an unreliable device, not an operator problem, and belongs in root cause analysis rather than retraining.
Follow-up matters more than the score. Every open action is reviewed at the team's daily meeting until it closes, and anything not closed by its due date escalates to the next tier. Once a month, review the results: retire questions that have passed for months, add questions from recent customer complaints, defects and near misses, and check that every scheduled audit was actually done.
How do you stop pencil whipping?
Pencil whipping is ticking yes without looking. It is the most common way a layered process audit program dies.
- Ask for evidence on some questions: a reading, a photo, a record number.
- Rotate the questions and the stations so the audit cannot be done from memory.
- Compare results with defects: a line with all yes answers and rising customer complaints is a signal.
- Have a higher layer re-audit a sample of stations soon after a lower layer.
- Make 'no' safe. A finding is the audit working; praise it, and act on it quickly.
- Keep it short. A 40-question audit invites guessing.
Does IATF 16949 require layered process audits?
The IATF 16949 standard does not name LPAs as a clause, but layered process audits are a customer-specific requirement of several vehicle makers for their IATF 16949 suppliers, and AIAG's CQI-8 is the published guideline. Check your customers' specific requirements. Outside automotive, the same checklist works in aerospace, food, pharmaceuticals and general manufacturing, and as a layered safety audit for quality and safety together.
Step by step
- Go to the station. At the scheduled time, with the checklist for that process step.
- Observe first. Watch the work and check documents, gauges and devices yourself before asking.
- Answer each question. Yes, no or not applicable, with a photo or reading where evidence is asked for.
- Fix on the spot. Correct what can be corrected with the operator and record what was done.
- Raise actions. An owner and due date for every 'no' that cannot be fixed now; escalate if overdue.
- Close the loop. Tell the operator what you found, review open actions daily and rotate the questions monthly.
A worked example
A metal pressing plant supplying automotive brackets started layered process audits on its three critical stations with a ten-question checklist. In the first month the team leader audits found two error-proofing sensors bypassed with tape and a gauge past its calibration date; both were fixed the same shift. The plant manager's monthly audit then found the reaction plan was unclear to night-shift operators, which became an action to rewrite the instruction and brief every crew.