Layered Process Audit FAQs for Aerospace: Who, What, When, How and Why

Leading automotive companies require suppliers to conduct layered process audits (LPAs), a requirement experts say may soon come to aerospace companies via the AS9100 standard.

LPAs provide daily checks of high-risk processes, verifying operator adherence to standard processes to minimize variation and defects. Aerospace companies that implement LPAs have cut defects by 53% in six months, offering convincing evidence that these frequent audits are worth the investment in time and resources.

For those considering implementing LPAs or information on best practices, following is an overview of LPA basics, addressing questions like who should participate, what LPAs cover, how to implement them and why they’re critical to quality.

Who Participates in Layered Process Audits?

Unlike traditional quality approaches, LPAs require participation from the entire organization. In fact, the “layered” in layered process audit comes from the different layers of management involved in conducting the audits.

In an LPA program, every employee is an auditor, from team leads up to plant managers and even executives. Auditors include employees from every department, including finance, human resources and administration. In other words, it’s about getting everyone involved in quality.

Cross-functional engagement is a central goal of LPAs and a basic requirement for a culture of quality. The process audits are short and easy to understand, so even those with minimal process knowledge can perform them.

In fact, non-experts can often provide observations that people who work the process day in, day out don’t see. Like the human resources employee at a leading automotive company who, asked to verify whether the operator followed the work instructions, noted they were none posted at the station at all.

What Do Layered Process Audits Cover?

Compared to a rear-facing product audit that inspects outputs, LPAs look at process inputs like resources, equipment and people to find errors. Typical areas for determining what questions to ask include previous customer complaints and high-risk processes identified in process failure modes and effects analysis (PFMEA).

LPA checklist questions should be yes or no questions that don’t require measuring product characteristics. Checklists should have no more than 10 questions, covering process elements such as:

Safety
Materials
Motions
Workstation design
Process for reporting issues
Documentation
Workstation design

When Do Layered Process Audits Happen?

LPAs are particularly powerful for improving quality due to the high number of audits required. While there’s no set rule for how often to conduct LPAs, participation frequency corresponds with each person’s level in the organization. For most companies, that means:

Daily audits by team leads and supervisors
Weekly audits by middle management
Monthly and/or quarterly audits by the plant manager and executives

Audits should take place as often as every shift, with separate audits for each build in a line or cell as well as for the changeover process itself.

How to Implement Layered Process Audits

Implementing an LPA program may sound difficult considering the number of people and audits involved. Breaking it down into manageable parts makes it easier:

Learning about LPAs: The Automotive Industry Action Group (AIAG) CQI-8 Layered Process Audit Guideline provides an in-depth look at LPAs, as does our free eBook on Process Audit Secrets.
Creating the LPA team: Involving the entire organization takes quality out of its traditional silo, making quality part of what people do every single day.
Writing audit questions: This is an area that organizations often struggle with. LPA questions should be objective, specific and easy for the layperson to understand.
Creating an audit plan: Start by defining your layers and at what frequency each one will participate.
Rolling out LPAs: You’ll need to create a schedule and process for sending reminders, providing updated checklists and triggering escalations for missed audits.
Monitoring and measurement: Leaders must review audit data regularly, tracking metrics like audit completion and corrective action closure rates. You also need to update questions, rotating out ones that always pass and introducing new questions based on newly identified risks.

Why Layered Process Audits are Essential to Quality

According to the American Society for Quality (ASQ), companies lose anywhere from 10 to 40% of revenue to quality-related costs. Verifying upstream processes is a high-leverage activity that ripples throughout the value chain, driving down scrap, customer returns and productivity costs.

LPAs increase visibility into critical processes, representing a proactive approach that lays the foundation for quality culture. An automated LPA system takes this concept further with:

Real-time reporting that doesn’t require manually entering checklist findings or crunching spreadsheet data
Corrective action capabilities to track non-conformances and ensure timely closure, reducing overdue CAPA requests by up to 93%
Data integrity protections such as time-stamping and question randomization to prevent pencil-whipping
Fast implementation on the order of weeks rather than the months required for paper-based systems
Automated scheduling and reminders to increase audit completion rates