Method guide · Quality management
Layered process audit (LPA): what it is, the layers, the questions and a worked schedule
Short answer
A layered process audit (LPA) is a short check, done at the station, that the critical steps and controls of a process are being followed. Several levels of leadership run the same kind of audit on their own schedules, from the team leader every shift to the plant manager every few weeks, so a process that starts to drift is caught within days.
An LPA is a list of five to ten yes or no questions about the high-risk points of one process: is the torque check recorded, is the work instruction the current revision, are rejected parts in the red bin with a tag. The auditor goes to the station, asks the operator to show each point and answers from what they see. A no is fixed on the spot if it can be, otherwise it becomes an action with an owner and a date. The word layered means the audits are done by several layers of the organization, team leaders most often and senior managers least often, so everyone from the line up checks that the controls hold.
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What is a layered process audit?
A layered process audit checks the process, not the product and not the person. It asks whether the controls that keep a part good are in place right now: the gauge is at the station and in calibration, the setting matches the sheet, the first-off check was done, the operator knows what to do when the tester fails. A plant writes these controls into its control plan and process FMEA once. The LPA is how it checks, every shift, that they still happen.
People search for it under several names. A layered audit, an LPA audit, layered process auditing and an LPA program all mean the same practice. The form the auditor carries is the LPA checklist, or layered process audit form. The free layered process audit checklist is a ready one with 20 checks in four groups.
- Short. Five to fifteen minutes, so it fits into a leader's day without being cancelled.
- Frequent. The first layer audits every shift; the higher layers weekly or monthly.
- At the station. Answers come from looking and asking the operator to show, not from records in an office.
- Layered. Team leaders, supervisors, managers and the plant manager all audit, each on a set schedule.
- Focused on risk. The questions cover the few points where a miss would reach the customer or hurt someone.
- Acted on. A no is fixed during the audit or assigned with an owner and a due date before the auditor leaves.
Why plants run layered process audits
Controls decay. A corrective action adds an hourly check after a customer complaint. For a month it is done every hour. By month six the sheet has gaps on night shift, the gauge has moved to another cell, and nobody has noticed, because nothing has gone wrong yet. Final inspection cannot see this: the parts can be good for weeks while the control that protects them has already gone. An LPA looks at the control itself, so it finds the gap before the defect.
The layers add a second effect. When the plant manager stands at a station and asks to see the torque record, the team hears that the record matters. When managers skip their audits, the team hears that too. LPAs put leaders on the floor on a fixed routine, which is why many plants write them into leader standard work for every level.
In automotive supply LPAs are often a customer requirement. Several vehicle makers ask for them in their customer-specific requirements, and the industry body AIAG publishes a guideline for running them, CQI-8 Layered Process Audits. Outside automotive the method is used the same way in aerospace, medical device, food and general assembly plants, wherever a skipped step reaches the customer.
The layers of an LPA and how often each audits
Most plants use three or four layers. The first layer is closest to the work and audits most often. Each layer above audits less often but over more areas, and brings a different eye: a team leader knows the station, a quality manager knows the failure modes, a plant manager sees whether the system around the station works.
| Layer | Who | Typical frequency | What this layer adds |
|---|---|---|---|
| Layer 1 | Team leaders or cell leaders | Every shift, in their own area | Catches drift within the shift; knows the station best |
| Layer 2 | Production supervisors, area leaders | Weekly, each area they run | Checks that layer 1 audits are real and their findings are closed |
| Layer 3 | Department managers: production, quality, maintenance, engineering | Weekly or monthly, rotating across areas | Fresh eyes from outside the area; can remove causes the line cannot |
| Layer 4 | Plant manager and senior staff | Monthly, rotating across areas | Shows the audits matter; sees system problems across areas |
These are common choices, not a rule. Set the frequency by risk: a safety-critical weld cell may get a layer 2 audit every day, a low-risk packing line a weekly layer 1 audit. If a customer specifies a frequency in its requirements, that sets the minimum.
Four layers, from every shift to every month
- Layer 4: Plant manager and senior staffMonthly, rotating across areasShows the audits matter; sees system problems across areas
- Layer 3: Department managers: production, quality, maintenance, engineeringWeekly or monthly, rotating across areasFresh eyes from outside the area; can remove causes the line cannot
- Layer 2: Production supervisors, area leadersWeekly, each area they runChecks that layer 1 audits are real and their findings are closed
- Layer 1: Team leaders or cell leadersEvery shift, in their own areaCatches drift within the shift; knows the station best
Two scheduling rules matter more than the exact frequency. Spread the audits across every shift, because night shift is where controls drift first and where leaders rarely go. And rotate the higher layers across areas, so a manager from maintenance audits assembly and the quality manager audits the paint line: an outsider asks the questions the area has stopped asking itself.
How to write LPA questions
The questions decide whether an LPA finds anything. Take them from the places where the plant has already written down its risks:
- The process FMEA: the failure modes with high severity or high action priority, and the controls listed against them. The PFMEA template shows where these sit.
- The control plan: each special characteristic, its check frequency, and the reaction plan when a check fails. See the control plan template.
- Recent customer complaints and internal escapes: a question that checks the fix is still in place.
- Recent corrective actions: for the first months after a fix, audit it at every layer to confirm the new method has stuck.
- Safety-critical steps: guards, interlocks, lockout points and PPE that the station depends on.
Then write each question so that two auditors standing at the same station would give the same answer. A question passes that test when it covers one thing, names the standard, and can be answered by looking or by asking the operator to show.
| Weak question | Better question | Why it is better |
|---|---|---|
| Is the operator following the work instruction? | Is the work instruction at the station the revision shown on the master list? | One thing, checked against a record |
| Is torque being checked? | Is the last hourly torque check on the check sheet, inside the hour? | Answered from evidence, not from memory |
| Does the operator know the reaction plan? | Ask the operator: what do you do if the leak tester fails twice in a row? Does the answer match the reaction plan? | Tests understanding, not a signature |
| Is the area organized? | Are rejected parts in the red bin, each with a reject tag? | Tied to a quality risk, not general tidiness |
| Is the operator trained? | Is this operator shown as trained for this station on the skills matrix? | A yes or no with a place to check it |
A good list for layer 1 has about eight questions and takes about ten minutes. Higher layers can add two or three questions about the system: are last week's findings closed, is the layer 1 sheet filled in honestly, does the board show the current numbers.
Keep a core set that appears on every audit for the highest risks, and a bank of rotating questions so the list does not turn into a ritual. When a question has been a yes at every layer for three months, move it to the bank and bring in a newer risk. Change only a few at a time, so this month's results can still be compared with last month's.
A layered process audit schedule: a worked example
This example is illustrative. A plant runs two shifts, five days a week, with four production areas: press, weld, paint and assembly. Each area has a team leader on each shift, so eight team leaders. There is a production supervisor on each shift, four department managers (production, quality, maintenance and engineering) and a plant manager. Layer 1 audits take about ten minutes with eight questions; the higher layers take about fifteen.
| Layer | Who and how often | Audits a week | Leader time a week |
|---|---|---|---|
| Layer 1 | 8 team leaders, own area, every shift | 4 areas x 2 shifts x 5 days = 40 | 40 x 10 min = 400 min, or 50 min per team leader |
| Layer 2 | 2 supervisors, each area once a week on their own shift | 2 x 4 areas = 8 | 8 x 15 min = 120 min, or 60 min per supervisor |
| Layer 3 | 4 managers, one audit a week each, areas rotated | 4 | 4 x 15 min = 60 min, or 15 min per manager |
| Layer 4 | Plant manager, one audit a week, areas rotated | 1 | 15 min |
| Total | 15 people | 53 | 595 min, just under 10 hours across the plant |
Check it the other way, per area: each area gets 10 layer 1 audits a week (5 days x 2 shifts), 2 from the supervisors, 1 from a manager and a plant manager visit every fourth week (0.25 a week). 10 + 2 + 1 + 0.25 = 13.25 audits per area, and 4 areas x 13.25 = 53.
Two rules finish the schedule. Each manager and the plant manager do at least one audit in four on night shift. And the rotation is written down a month ahead, so nobody chooses the area that looks best that day. The cost is about ten leader hours a week for a check of every area on every shift, which is less than one shift of one person.
Now one week of results from the same plant, also illustrative. Layer 1 did 39 of its 40 audits, layer 2 did 7 of 8, layer 3 did 2 of 4 and the plant manager did 1 of 1.
| Measure | Calculation | Result |
|---|---|---|
| Audits completed | 39 + 7 + 2 + 1 done, against 40 + 8 + 4 + 1 planned | 49 of 53, 92% |
| Layer 3 completion | 2 done / 4 planned | 50% |
| Questions answered | 39 audits x 8 questions + 10 audits x 10 questions | 312 + 100 = 412 answers |
| Answers counted | 412 answers minus 12 N/A | 400 yes or no answers |
| Conformance | 382 yes / 400 yes or no answers | 95.5% |
| Findings | 18 no answers: 11 fixed on the spot, 7 logged with an owner and a date | 18 |
Check it the other way: 382 yes + 18 no + 12 N/A = 412 answers, and 400 x 0.955 = 382. Conformance counts yes against yes plus no, leaving N/A out, the same way the checklist template scores a group.
The headline numbers look healthy: 92% of audits done and 95.5% conformance. Two things in the detail matter more. Layer 3 did half its audits, and if that is not raised at the next weekly review, the floor will soon learn that managers do not take part. And 6 of the 18 no answers were the same question, the hourly torque check record in assembly, on both shifts. When one question gives a third of the findings, the cause is in the system (a check sheet hung at the far end of the line, a gauge shared with another cell), not in the operators. That finding goes to a root cause, not to a reminder.
How to run one LPA at the station
The layered process audit cycle
- 1Plan
Schedule by layer
- 2Do
Audit at the station
- 3Do
Fix on the spot
- 4Do
Log the rest with an owner
- 5Check
Review by layer and question
- 6Act
Update the questions
Back to step 1: the next audit uses the updated questions
- 1
Go to the station with today's questions
Take the core questions for the area plus the rotating ones for this audit. Introduce yourself if the operator does not know you and say what you are checking: the process, not them.
- 2
Ask the operator to show you
For each question, ask to see the thing itself: the check sheet, the gauge, the setting on the screen, the reject bin. Answer yes, no or N/A from what you see, not from what you are told.
- 3
Fix what you can before you leave
A missing record that the operator can fill in, a gauge in the wrong place, an old work instruction with the new one in the binder: put it right with the operator and mark the no as fixed on the spot.
- 4
Log the rest with an owner and a date
Anything that cannot be fixed during the audit gets a short description, an owner and a due date. Raise it where the area already tracks its problems, so it is seen at the next huddle.
- 5
Tell the operator what you found
Thank them, say what was good and what you logged. If the no came from the process making the right way hard, say so.
- 6
Record the audit as done
An audit that is not recorded counts as missed. Completion by layer is the first number anyone will look at.
LPA findings and follow-up
An LPA program is judged by what happens to its findings. A plant that scores 95% every week and changes nothing has built a paperwork exercise. Treat a no in one of three ways, depending on what it is:
| Finding | Example | Action |
|---|---|---|
| One-off, fixable now | The 10:00 check was done but not written down | Fix on the spot with the operator; count it as a finding fixed |
| Needs someone else | The torque gauge is overdue for calibration | Log with an owner and a date; review at the next team or tier meeting |
| Repeat or systemic | The same question fails on both shifts for three weeks | Root cause, then a corrective action; audit the fix at every layer |
Review the results each week where the plant already reviews its other numbers, at the tiered meeting for the area and at the plant level. Four measures are enough: audits done against planned for each layer, conformance by area, the questions with the most no answers, and findings closed by their due date. Rank the questions by how often they fail, a Pareto of the nos, and start with the top one; the free Pareto chart maker draws it from a list of counts.
A repeat finding is a sign that the fix on the spot keeps putting a symptom right. Take it into a root cause analysis, and if the cause is in the method or the equipment, open a corrective action and track it on a CAPA log. Then add a question that checks the new method to every layer's list for the next few months.
LPA compared with other audits
Plants that start LPAs often already run several other checks. They do different jobs, and an LPA replaces none of them.
| Check | Who does it | How often and how long | What it looks at |
|---|---|---|---|
| Layered process audit | Leaders at every level | Every shift to monthly; 5 to 15 minutes | A few high-risk controls at one station |
| Manufacturing process audit | Trained internal auditors, independent of the area | On a planned program; hours per process | The whole process against the control plan, PFMEA, records and requirements |
| Product audit | Quality staff | On a sampling plan | Finished parts against the specification |
| 5S audit | Area team and leaders | Weekly or monthly; 15 to 30 minutes | Workplace organization and standards |
| Gemba walk | Leaders | Daily or weekly | Observing the work and asking questions, with no score |
In automotive, IATF 16949 clause 9.2.2.3 asks for manufacturing process audits; LPAs usually come from customer-specific requirements on top of it. The [process audit checklist](/templates/process-audit-checklist) covers the full audit of one process. The [ISO 9001 internal audit checklist](/templates/iso-9001-internal-audit-checklist) covers the system audit, and [gemba walk vs audit](/blogs/gemba-walks-vs-audits-key-differences-manufacturing) explains where a walk ends and an audit starts.
A kamishibai board is not a separate kind of audit. It is a way to schedule and show LPAs: one T-card per audit, red side out until it is done, green after, arranged by layer and frequency, so anyone walking past sees which audits are overdue. The kamishibai audit board is a ready one.
Layered process audit forms, boards and software
Most plants start on paper, and paper is the right way to test the questions on one area. A layered process audit checklist carries the header (area, station, shift, layer), the questions with yes, no and N/A, a box for a no fixed on the spot and a findings table with owners. A kamishibai board on the wall shows who has done their audit.
Paper starts to hurt when the program grows past one area. Nobody can see in one place which audits were missed, the same failed question on three lines never meets in one report, and findings live on sheets that are filed, not closed. That is the point to look at LPA software. What it should do: schedule audits by layer and role with a repeat rule, show missed audits, take photos as evidence, turn a no into an action with an owner, and report completion and the most failed questions by layer, area and shift. Best layered process audit software compares seven tools on those points.
In LeanSuite, Audit Management does this. You build the LPA checklist in Lean Creator, or let the AI draft it, and schedule it in Daily Standard Work to a person, a role or an asset with a repeat rule, so the same checklist runs for each layer. Auditors complete their checks on a phone or tablet with photo evidence where required. Rules on an answer can flag it or raise a tag, idea or Kaizen; each report shows its score and pass or fail; missed audits show in red on the calendar and Kanban board; and reports track completion and the most common non-conformances.
Common LPA mistakes
- Auditing from the office. An LPA done from records misses what the operator is actually doing. Go to the station every time.
- Only layer 1 shows up. When managers skip their audits, the team learns that the checks are optional. Report completion for every layer, not one plant number.
- Questions nobody can fail. General questions such as is the area clean are always yes. Write each question against a specific risk and a specific standard.
- Auditing the operator instead of the process. A no usually means the process makes the right way hard. Fix the process and say so to the operator.
- Findings with no owner. A no that is written down and left changes nothing. Every finding is fixed on the spot or has an owner and a date.
- A list that never changes. After months of yes at every layer a question tells you little. Rotate a few questions at a time and keep the core stable.
- Day shift only. Controls drift first where leaders rarely go. Put night and weekend shifts into every layer's rotation.
Kamishibai Board Software
Run layered process audits in LeanSuite
Kamishibai board software: digital T-cards for layered process audits, scheduled by cadence, red until done, every finding tracked to an action.
Go deeper
This page is the short version. These guides cover each part in full.
- Kamishibai Board: Lean Audit Management for ManufacturingRunning LPAs and other short audits with T-cards on a board, red until done.
- Gemba Walk vs Audit: Purpose, Method and When to Use EachWhere an observing walk ends and a scored audit starts, and when to use each.
- How to Audit Standard Work: A Verification GuideFormal standard work audits, how they differ from daily leader checks, and what to do with a gap.
- Leader Standard Work: Daily Leader RoutineBuilding the leader routines that LPAs usually sit inside.
All our articles on this subject are in the quality management topic.
Free templates and tools
- Kamishibai audit boardT-cards for daily, weekly and monthly audits by layer, red until done and green after, as a Lean Studio board.
- Layered process audit (LPA) checklist20 yes, no or N/A checks at the station, a fixed-on-the-spot box, scores by group and a findings table.
- Process audit checklistAudit one process from inputs to results: 32 questions graded conforms, minor or major, a product check, a score by group and a findings list.
- Standard work audit checklist24 checks of a job against its written standard, ten timed cycles, and each gap sorted by cause before anyone acts.
- Control plan templateWhat is checked at each step, against which limits, how, how often, and what to do when a result is out.
- PFMEA template (process FMEA)Failure modes, effects and causes rated for severity, occurrence and detection, with RPN before and after action.
- Supervisor leader standard work templateA supervisor's daily, weekly and monthly routine with a box per day, an escalation log and a weekly review.
- CAPA log templateAn Excel CAPA tracker with status, days open, late flags and counts by source, plus a printable log and monthly review.
- Pareto chart makerPaste categories and counts: sorted bars, cumulative percentage line and the vital few at the 80% line, as a PNG or SVG.
Doing this in LeanSuite
Audit Management
Build, schedule and act on any shop floor audit, from gemba walks to 5S and layered process audits, and turn every finding into a tracked improvement.
See Audit ManagementKamishibai Board Software
Digital T-cards for layered process audits, scheduled by cadence, red until done, with every finding tracked to an action.
See Kamishibai Board SoftwareDaily Issue Management
Gives frontline teams one place to flag, track and resolve issues in real time, so the same fires stop coming back every week.
See Daily Issue Management
Open this board in LeanSuite
The kamishibai audit board is one of the 30 ready-made boards in Lean Studio, LeanSuite's whiteboard. Try the interactive demo in your browser with sample data, or pilot LeanSuite on your own lines for 90 days, with the setup done by our team.
What Lean Studio isFAQ
Questions about layered process audit (LPA)
An LPA, short for layered process audit, is a short, frequent check at the station that the critical steps and controls of a process are being followed. It is done by several layers of leadership on their own schedules, team leaders every shift and managers weekly or monthly, with a few yes or no questions. A no is fixed on the spot or assigned to an owner with a date.
Usually three or four. Layer 1 is team leaders or cell leaders, auditing their own area every shift. Layer 2 is supervisors, weekly. Layer 3 is department managers such as production, quality, maintenance and engineering, weekly or monthly across areas. Layer 4 is the plant manager and senior staff, monthly. Plants with three layers combine the top two.
Set it by risk. A common pattern is every shift at layer 1, weekly at layer 2 and monthly at the top layers, spread across every shift. A high-risk station can be audited more often. If a customer sets a frequency in its requirements, that is the minimum.
Five to fifteen minutes. A layer 1 list of about eight questions takes about ten minutes; higher layers may add two or three questions about the system, such as whether last week's findings are closed. If an audit takes longer than fifteen minutes it will start being skipped.
Questions about the high-risk controls of the station: the high-severity failure modes in the process FMEA, the checks and reaction plans in the control plan, recent customer complaints, recent corrective actions and safety-critical steps. Each question covers one thing, names the standard and can be answered by looking, for example: is the last hourly torque check on the sheet, inside the hour.
A process audit is a long, planned audit of a whole process by trained auditors on a planned program, taking hours. An LPA is a short check of a few high-risk controls, repeated every shift or week by leaders at every level. The process audit checks the full system; the LPA checks that its most important controls hold day to day.
IATF 16949 asks for manufacturing process audits in clause 9.2.2.3 but does not name LPAs. Many automotive customers require LPAs from their suppliers through customer-specific requirements, and AIAG publishes a guideline for running them, CQI-8 Layered Process Audits. Check your customers' requirements for the frequency and records they expect.
If it can be put right during the audit, the auditor fixes it with the operator and records it as fixed on the spot. If not, it is logged with an owner and a due date and reviewed at the next team or tier meeting. A finding that repeats across shifts or weeks goes to root cause analysis and a corrective action.
A kamishibai board is a way to schedule and show LPAs. Each audit is a T-card, arranged by layer and frequency, red side out until the audit is done and green after. Anyone walking past sees which audits are overdue, and the card can carry the questions for that audit.
Related guides and tools
- Layered process audit checklist: 20 checks in four groups, scores and a findings table, free PDF and Excel
- Best layered process audit software: seven LPA tools compared on scheduling, findings and reports
- Audit management in LeanSuite: schedule the same LPA for each layer and turn every no into a tracked action
- Leader standard work: the daily routine for each level that LPAs fit into
- What is a gemba walk: the observing walk that sits beside the scored LPA
- Lean software for automotive plants, where LPAs are part of the job
- SOP compliance on the floor: checking the SOP is followed between audits
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