In manufacturing, variation is the enemy of quality. Left unchecked, it erodes reliability, increases waste, and drives up costs. One of the simplest but most effective tools for controlling variation is Layered Process Auditing (LPA).
What is Layered Process Auditing?
At its core, an LPA is a short, structured check of a process to confirm that critical steps are being followed. Unlike system or product audits, LPAs are carried out right at the job site with the people doing the work. They’re not one-time events but ongoing checks performed at different levels—or layers—of the organization
For example:
- A supervisor might audit a workstation daily.
- A department manager might perform a broader audit weekly.
- A plant manager might step in monthly.
The frequency decreases as you move up the hierarchy, but each layer looks at the same few critical items. This repeated attention reinforces standards, keeps leadership connected to the shop floor, and makes sure important process steps don’t slip.
Why LPAs Matter
LPAs aren’t about paperwork. They’re about visibility and accountability. Done well, they:
- Provide early warning of process drift
- Reinforce the importance of key standards
- Reduce defects, waste, and safety risks
- Strengthen communication between operators and management
- Lower the total cost of manufacturing
And they don’t have to take long. In fact, the most effective LPAs last about ten minutes or less.
Getting Started with LPAs
Launching an LPA system takes planning. A cross-functional team should set the scope, identify critical processes, and build simple one-page audit checklists
The team also needs visible support from senior leadership, without which, the system will quickly lose momentum.
Some practical starting points include:
- Focus first on mature, stable processes with higher product severity.
- Use past customer complaints or internal defect data to develop audit questions.
- Train auditors at each level so they understand both the purpose and the process.
- Keep the checklists short and consistent to encourage daily use.
Avoiding Common Pitfalls
Organizations sometimes fall into traps that undermine LPA effectiveness. Common pitfalls include:
- Long, clunky audits that take too much time
- Paper-based systems that bog down reporting
- Outdated checklists that no longer reflect current risks
- Treating LPAs as “islands” instead of tying them into corrective action systems
LPAs should be sharp, simple, and integrated into your broader quality management system.
Practical Insights from the Field
Over time, a few lessons stand out across industries:
- Focus matters. LPAs work best when they zero in on a handful of critical process drivers rather than scattering attention across too many issues.
- They prevent costs, not just save them. The real financial impact of LPAs is in cost avoidance — stopping problems before they reach customers.
- Don’t overdo it. An audit that drags people away from their work for hours isn’t an LPA — it’s a misuse of the tool.
- Consistency is the key. Whether you choose the start, middle, or end of a shift, the schedule should be regular and predictable.
- Flexibility is essential. Each organization has to tailor its audit frequency and team selection to fit resources and culture.
When organizations respect these principles, LPAs become more than a checklist—they become part of the culture. And that culture of accountability and focus is what drives lasting improvements in quality and reliability.
Ray Harkins is the General Manager of Lexington Technologies in Lexington, North Carolina. He earned his Master of Science from Rochester Institute of Technology and his Master of Business Administration from Youngstown State University. He also teaches manufacturing and business-related skills such as Reliability Engineering Statistics, Quality Engineering Statistics, Failure Modes and Effects Analysis (FMEA), and Root Cause Analysis and the 8D Corrective Action Process through the online learning platform, Udemy. He can be reached via LinkedIn at linkedin.com/in/ray-harkins or by email at the.mfg.acad@gmail.com
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