Layered Process Audit

Today we will talk about layered process audits.

LPA, or Layered Process Auditing, is a quality technique developed for manufacturing management. When used correctly, LPA brings your organization to improve quality, minimize scrap and rework, plus reduce customer rejections by driving cultural change throughout your company. To gain a better idea and to understand what LPA means we will have a little deep dive.

Layered Audits are a defined approach that devotes time and resources to ensuring that high-risk procedures and error-proofing mechanisms are consistent and functional. Therefore, three important components make up a Layered Process Auditing System:

• Full focus on High Risk Processes (HRP) by a list of defined audits

• Depending on layer of audit the audit itself is performed from various levels of management

• A system of reporting and follow-up to ensure that containment is maintained based on specific needs. But also, to maintain and drive the continuous improvement process in your organization

A full stack of audits

This part of a Layered Process Auditing System is straightforward. Audits are merely a set of questions aimed to investigate machinery or processes. An LPA system's audits should concentrate solely on parts of the value adding process where deviation poses a high risk of producing defective products. E.g. if you have an end of the line quality check station that is measuring crucial parameters or functions that are critical to customers of your product and the calibration is wrong, you are producing in Takt defective or non-conforming products. No need to mention that you should keep an eye on that process. With the help of a proper LPA system you will have the EOL station within the layers allowing containment and corrective action as soon as the station surpasses set tolerances.

Multiple layers of audits comes with multiple layers of auditors

Multiple layers of authority from across your manufacturing department conduct audits on a regular basis, at a predetermined frequency, in an LPA system. For example, once per shift, the Shift Leader conduct an audit that checks the parameters or settings of your EOL-Station. Another layer of management, which may include process engineers, maintenance staff, or even the human resources department, would circulate through the system performing the exact same audit. The sample audit might be performed once a week or once a month by someone in the layer by assigning a number of auditors to this layer and establishing a timetable that cycles through the system's audits. Yet another layer of management, such as the plant manager or even executive staff (the number of levels in an LPA system can vary enormously from facility to facility, depending on your organizations demands and needs). This extra layer of auditors performs the same collection of audits on a rotating schedule, concluding the example audit once a month or once a quarter, for example.

Countermeasures, Containment Actions, Reporting and Improvement Process

In order to have an effective, a Layered Process Audit system you’ll have to combine analysis, measures and improvement process.

If an auditor observes a non-conformance during an audit, the auditor should not only document their findings but also take quick appropriate action to ensure that defective products do not leave the facility. In order to help with the documentation and immediate actions you can use the A3 report and methodology. Simple but effective. You can find it here. Anyway, the findings should be documented and made readily available to management for further analysis. An LPA system is a handy tool for debugging problem areas and identifying areas that are suitable for improvement actions when combined with a strong system for recording and reporting these audit results. A systematic approach will be discussed in the Shop Floor Mgmt. article.

Though Layered Process Audits may be developed to meet a customer or corporate demand, effective LPA systems are built, implemented, managed, accountable to, and owned by your participatory manufacturing management group. A solid LPA system may help you to take proactive control of your manufacturing operations while also enhancing product quality and business bottom line.