In the perfect manufacturing environment, product quality would be effortless; there would be zero defects, no re-work and non-conforming products simply would not exist. Unfortunately, in the real world of manufacturing, product quality is an ongoing process that requires checks, verification and documentation of materials and processes, as well as training and communication, up and down the manufacturing enterprise.
But even when quality systems are in place to control a manufacturing process, operator mistakes, material variations or human errors can enter the process, which in turn lead to non-conforming products, defects, re-work, production delays and additional costs. In theory, management oversight should prevent these problems, but in practice, it may not be as thorough or as frequent as it needs to be. Clearly, another solution needs to be implemented to error proof processes and ensure process quality.
The above scenario is one of the reasons why layered process audits are implemented in manufacturing operations, spanning not only the assembly floor, but also shipping, distribution, engineering and other support functions. Layered process audits position manufacturing enterprises to obtain the following benefits:
- Reductions in product variations
- Greater discipline in following standard work procedures
- Decreased wasted material, scrap, rework and rejects
- Assist the production staff’s “buy in” to the quality culture
- Better communication between operators and leadership
- Overall improvements of the entire manufacturing ecosystem
- Greater efficiency with cost reductions.
What Are Layered Process Audits?
Layered process audits improve the overall quality of a manufacturing process through an active auditing system, conducted by cross functional audit teams, that verifies compliance to a documented quality process. The audit teams perform process audits or checks at frequent as well as rotating intervals (i.e., daily, weekly, monthly and quarterly) to ensure compliance to standard work procedures for “high risk” processes and “error proofing” devices that are likely to allow the production of non-conforming or defective parts. By utilizing cross-functional audit teams, work standards are reinforced, quality problems are quickly identified and contained (often times as they occur). Moreover, layered process audits provide a framework to remediate problems and implement changes for improvement.
Auditing Layers Are Key
The benefits derived from layered processed audits is simpler than it sounds. Using a double check approach to verify compliance to a standard, layered process audits employ various layers or stakeholders, ranging from supervisors, team leaders, managers, engineers, plant managers and executive managers, across a manufacturing enterprise’s leadership that not only establishes a sense of ownership of the process, but also creates an institutionalized means for stakeholders to double check each other’s audits to increase the likelihood that defective products are caught early in the process, enabling their containment, before escalating into a larger and more profound problem downstream.
Frequent Checks Make the Difference
The frequency of layered process audits make the difference between general oversight of a production process and the close examination of a process as required by the layered process audit structure. LPA audit teams closely evaluate a production process against a quality standard, introduce corrective actions when needed and follow up with plans for improvements. In addition, executive management is involved in the process as much as the team leader or an operator by auditing process reviews to ensure compliance.
In application, layered process audits get down to the details of process quality with frequent checks specific to a work station, production line, team, group or area of a manufacturing operation. High risk processes and devices are verified at least once per shift. Supervisors audit quality documentation daily to ensure that operators are completing it fully. Shift leaders double check audit reviews previously completed. Area managers audit supervisors’ process reviews weekly. Senior management conduct LPAs on a monthly or quarterly basis.
Reinforcing a Culture of Quality and Accountability
Since layered process audits involve all levels or layers of management, a culture of quality and accountability is instilled throughout the enterprise. By ensuring the consistent application of standards, LPAs improve in-place quality systems as well as open the lines of communication between operators and leadership. This level of involvement inculcates greater discipline throughout the manufacturing organization, which inspires each individual to assimilate an attitude of continuous improvement. In global manufacturing enterprises, where financial success is often directly correlated to product quality, layered process audits take on a new level of significance.