Layered Process Audit – LPA is one of the most important elements of organization’s quality system improving. Thanks to their proper implementation, we gain confidence that the number of invoices for quality problems from the field and 0-km will not affect the main operational activities in the company and will guarantee their reduction.

In addition, we can not forget about safety issues, maintenance components that can be performed by production employees, as well as the ability to identify internal notifications, i.e. non-conformities that have not been sent to customers. Above issues, of course, also belong to the scope of the LPA.

When carrying out Layered Process Audit, it is worth remembering a few good practices that will allow us to increase their efficiency and raise the awareness of both auditors and people participating in the audit.

Communication, communication and again communication

When we’re dedicated to audit performing on a production line, it is worth arranging in advance the time and duration of the audit with the production leader at which such activity will be carried out. This is due to the fact that, in addition to participating in the audit, the production leader has many other activities to perform during the shift, and the audit that we want to carry out will certainly not belong to his priorities. This does not automatically mean, that production approaches LPA in a marginal way.

During the meeting with the leader, it is also worth determining which production station will be audited in order to provide such information to the employee whose knowledge will be verified. In addition, the leader will have the opportunity to prepare appropriate workplace documentation in advance, if it is not directly available at the workplace – for example, it’s kept at the leader’s pulpit.

Calibration – how to increase competences between individual levels of auditors

The very name of layered audits comes from the level of people (layers) who carry it out. We usually deal with three levels, starting with the production leader who performs such an audit on his shift, through middle managers, and ending with the director of the plant or a dedicated person from a senior management.

layered audits - performed audits reporting

Fig. 1 Example of audits level for individual production lines reporting

This approach gives the opportunity to calibrate auditors between individual levels of auditors in order to develop a proper interpretation regarding potential non-compliance. In practice, an auditor from one level (e.g. a manager) invites to participate in an audit of an auditor from another level, e.g. a production leader. In this way, the organization receives a tool to increase the competence of auditors conducting layered audits.

Owners defining for found nonconformities

One of the activities that the auditor carries out after the audit is to report the non-compliances found together with the owner and the planned date of their completion. At this stage, it is important that when the person responsible for removing the non-compliance is defined, he / she is informed about this fact. Thanks to this approach, it is possible to avoid situation, when such person  will be a process engineer who did not participate in the audit. We can solve the problem by defining the leader as the owner for all open points. Then she/he will get in touch with the relevant people directly.
The second approach is to organize a closing meeting with the leader and people who should be assigned to the non-compliance found. Thanks to this approach, all audit conclusions can be additionally discussed, and each person participating in the meeting is aware of the open points that must be properly managed.

Production line audit vs. workstation audit

An important element when conducting Layered Process Audit is the verification of each workplace. For this reason, the organization should ensure that each position is verified for each production line (at least once a month). Only in this way can we confirm the verification of all workstations. This is a very important starting point for defining system activities in a situation where the same non-compliance is found in several workstations.

In order to guarantee the verification of each workplace by auditors, you can use appropriate software. Another option is management through appropriate visualization. For this purpose, to LPA and list of non-compliances, can be added simple spreadsheet with workstation numbers and dates of audits carrying out. In this way, the person conducting such activity has information about which stations have already been audited in a given month, and which ones should still be audited.

Audit question list is not a document which is created only once

The last good practice is to pay attention to the content of the questions on the list. We should remember that, just like FMEA is a “living document”, the same approach should be followed when conducting LPA’s. Therefore, as input for modification of audit questions, comments and observations after visits of the certification body and customers, as well as after corporate audits, should be included.

We must also remember that automotive customers may have additional recommendations in this topic. The best example is GM, which recommends that Tier 1 should have one blank field in the audit list, thanks to which it will be possible to place a question in it, that will be applicable for a certain period of time (e.g. Lock-out Tag-out (LOTO) procedure kick-off in area of maintenance or verification of the effectiveness of implemented actions after claim obtaining).