Keeping Quality High: The Benefits of a Layered Process Audit

Manufacturers in the United States employ more than 8.5 percent of the total workforce. Additionally, they account for over 10 percent of the country’s gross domestic product (GDP). However, as the scale of manufacturing ramps up, so does regulatory oversight. Consequently, regulators must ensure that products meet standards such as the ISO 2859-1 acceptance quality limit (AQL).

For Quality Managers, Plant Managers, and Process Improvement Leads, maintaining compliance with frameworks like ISO 9001, IATF 16949, and VDA 6.3 is a constant challenge. This is especially true when paper-based audits make it difficult to track non-conformance rates and achieve cross-site comparability. Failure to maintain quality standards can result in significant consequences. For example, in 2021, the car manufacturer Toyota agreed to pay a record $180 million fine for producing vehicles with faulty emission-control components.

To help avoid this issue, manufacturers benefit from a focus on continual quality assessment and improvement. One effective way to achieve this goal is by using a Layered Process Audit (LPA). Here’s what that looks like in practice.

What is a Layered Process Audit?

A Layered Process Audit system focuses on frequent and ongoing assessment of existing processes. In other words, its purpose is to pinpoint potential issues and identify opportunities for improvement. Original equipment manufacturers (OEMs) in the automotive industry often use these audits. Notably, LPAs focus on improving current standards or processes rather than examining finished goods or defective products.

While evaluating finished products for defects is also a critical aspect of quality control, LPAs take a different approach. Specifically, they look to reduce the number of defects by identifying and remediating their root causes.

These audits can help companies achieve AQL goals and reduce the number of product batches that must be rejected. For example, consider a production run of 1,000 units with an AQL of 1 percent or 10 units. Therefore, if 11 units are defective, the entire run must be rejected. A Layered Process Audit looks to find processes that negatively impact AQL. It then adjusts or eliminates them accordingly to ensure quality standards are satisfied.

Furthermore, LPAs align directly with the broader quality management standards that govern manufacturing operations. Organizations pursuing ISO 9001 certification rely on systematic process audits to demonstrate continual improvement. Similarly, automotive manufacturers following IATF 16949 and VDA 6.3 use layered audits to verify process effectiveness at every level. In addition, CQI standards reinforce the value of structured, repeatable audit programs.

By tying Layered Process Audit findings to key performance indicators, teams gain a data-driven approach. These indicators include first pass yield (FPY), cost of poor quality (COPQ), and time to resolution. As a result, Quality Engineers and Lead Auditors can reduce non-conformance rates and drive measurable improvements across the entire quality management system.

Unpacking the Layers of a Process Audit

A Layered Process Audit program typically has three layers. Each layer corresponds to a different level of management personnel responsible for conducting audits.

Layer 1 refers to shop floor supervisors and production line team leaders. They conduct high-risk process audits daily and across every shift. Consequently, these audits help identify patterns of behavior or operation that could negatively impact overall quality. With digital audit tools, Layer 1 auditors can capture findings on mobile devices in real time. This eliminates paper-based checklists and ensures that data is immediately available for analysis. In particular, this is a significant improvement over manual processes that contribute to audit fatigue.

Layer 2 includes various levels of middle management staff. They typically conduct audits once or twice a week. Using feedback from Layer 1 auditors along with their own assessment of processes, Layer 2 personnel help prioritize larger-scale issues. Moreover, digital platforms enable Layer 2 managers to compare audit results across shifts and production lines. This improves cross-site comparability and makes it easier to spot systemic trends that paper records would obscure.

Layer 3 brings in plant managers who conduct audits monthly. Executives may audit processes once per quarter or once per year. This final Layered Process Audit layer combines the feedback of previous layers. Above all, its goal is to ensure that process changes have been implemented. It also identifies areas where more improvements are needed to address quality issues and create robust control plans defined by clear metrics.

For VP-level quality leaders, automated dashboards consolidate Layer 1 through Layer 3 data. They provide audit completion rate summaries and non-conformance trend reports. Consequently, this reduces audit fatigue and supports faster executive decision-making.

Making the Most of Your LPA Process

To ensure your Layered Process Audit system delivers desired process quality improvements, three factors are critical:

• Effective issue identification

To improve quality processes, companies must first identify key issues. While it’s possible to build your own LPA evaluation criteria from scratch, purpose-built solutions can help. Specifically, they address issues in quality management systems (QMS) and environmental management systems (EMS).

• Clear communication

Once teams identify issues, companies need clear communication. Specifically, staff members must be fully informed of process control roadblocks and understand the need for improvement. Here, the goal isn’t placing blame. Instead, teams work together to create processes and preventative actions. These actions both reduce defect rates and make production lines more efficient.

• Quick corrective action

Finally, companies must take follow-up corrective action in as close to real-time as possible. Simply identifying issues isn’t enough. Instead, all three audit layers must work together to define a solution, implement it, and document the results. Additionally, automating corrective action workflows eliminates the delays inherent in manual processes. This helps Quality Supervisors track every finding from detection through verified closure.

This is especially critical as manufacturing processes evolve. What solves a problem one month may not be sufficient the next. As a result, continued Layered Process Audit programs are critical.

Frequently Asked Questions (FAQs)

What industries benefit most from layered process audits?

While LPAs originated in the automotive sector to meet IATF 16949 and VDA 6.3 requirements, they are now widely adopted across many industries. These include manufacturing, food and beverage (HACCP), and pharmaceuticals (FDA cGMP). Furthermore, any industry governed by ISO 9001 can benefit. In fact, any organization that relies on repeatable processes and must demonstrate continual improvement gains value from a structured Layered Process Audit program.

How do layered process audits differ from traditional quality audits?

Traditional quality audits typically examine finished products or review documentation at scheduled intervals. LPAs, by contrast, focus on verifying that processes are followed correctly at every management layer. This spans from shop floor supervisors to plant executives. Moreover, they operate on a daily, weekly, and monthly cadence. This multi-layered frequency catches deviations before they result in defective output.

What KPIs should we track to measure LPA effectiveness?

Key metrics include audit completion rates, non-conformance rates, first pass yield (FPY), cost of poor quality (COPQ), and time to resolution for corrective actions. Tracking these KPIs over time reveals important insights. Specifically, it shows whether your Layered Process Audit program is driving genuine process improvements or simply generating paperwork.

How can digital tools reduce audit fatigue in an LPA program?

Paper-based audits create administrative burden that leads to audit fatigue and inconsistent data capture. However, digital audit platforms automate scheduling and enable mobile data collection. They also generate real-time dashboards. As a result, auditors at every layer complete checks faster. Meanwhile, Quality Managers gain immediate visibility into findings across all sites.

How often should each layer of an LPA be conducted?

Best practice calls for Layer 1 audits daily across every shift. Layer 2 audits should occur one to two times per week. Layer 3 audits happen monthly or quarterly depending on organizational size. The key is consistency. A regular cadence at each layer ensures that process deviations are caught early. It also ensures that corrective actions are verified promptly.

Bottom line? Layered process audits are part of the cost of quality. When implemented effectively, they help pinpoint issues. Consequently, they help companies reduce total defects, enhance product quality, and improve production line performance.

Looking to build a Layered Process Audit program? Start with Certainty.