Compare the following process audit questions, asking which would be more effective at preventing defects:
Question A: Does the operator know how to handle non-conforming material?
Question B: Can the operator describe each step of the non-conforming material process according to the quality manual?
Clearly, Question B is more likely to identify errors that result in defective product reaching the customer—the main goal of layered process audit (LPA) requirements for General Motors (GM) and Fiat Chrysler suppliers. These high-frequency audits focus on how products are made, and are also gaining traction in industries like aerospace as a best practice for minimizing variation, defects and quality costs.
People often struggle with writing LPA questions, which limits the results they see with these unique process audits. Here we examine how to make questions more objective, specific and concise, ensuring you get value from the audits without making them overly complex.
Make Layered Process Audit Questions Objective
LPAs involve everyone from front-line supervisors to engineers, executives and even people from departments like administration and finance. Many of them aren’t familiar with the individual processes being audited, so it’s critical that process audit checklist questions are objective. That means avoiding subjective terms like “proper” and “correct,” replacing them instead with clear pass/fail criteria.
Here are three examples of how to make process audit checklists more objective:
Before: Is the poka-yoke device working properly?
After: Does the poka-yoke device show the master defective part as failed?
Before: Has the voltage meter been calibrated at the correct frequency?
After: Was the voltage meter calibrated at the beginning of the shift?
Before: Are stray parts and components identified appropriately?
After: Do all loose parts and components have an identification tag complete with part type, operator name, time, and date.
Get Specific with Layered Process Audit Questions
For organizations using paper checklists, there’s often a temptation to use a universal checklist that applies to all work areas or processes. While this is understandable given the difficulty of updating and tracking paper checklists, overly generic questions deliver little meaningful value. Instead, you’ll want to have a checklist that’s specific to the work area or part, something that’s easier to customize with an automated LPA platform.
Let’s look at three more examples, this time examining how to make process audit checklist questions more specific so they add value:
Before: Do all materials contain lot traceability information?
After: Does each part’s trace tag contain a lot and batch number matching the raw material label?
Before: Is the operator following acid bath procedures?
After: Is the operator double-checking the amount of acid being put into the acid bath?
Before: Does the operator use the correct torque setting?
After: Does the torque setting used match the call out in the current work instruction?
Keep Layered Process Audit Questions Concise
The high frequency of LPAs, which take place every shift, means that you’ll need to keep them short and to the point. Aim for no more than 10 to 15 questions, so the audit takes about 10 minutes to complete.
Organizations can make process audit checklists questions simpler by breaking complex questions into parts and avoiding jargon. Here are three examples of how to break vague, multi-step questions into smaller, more targeted verification questions:
Before: Is the operator using the most recent version of standard work instructions, following each step in the process while demonstrating an ability to explain the what, why and how of each step?
- Are job instructions posted in the work area?
- Does the version number match the most recent version in the document management system?
- Does the operator follow each step listed in the instructions?
- Can the operator explain why each step is necessary?
Before: Are reject parts labeled with part number, date, quantity, defect and description and placed in a designated location away from the main production area where they cannot mix with other parts?
- Do reject parts have red tags containing part number, date, quantify, defect and description?
- Are all red-tagged parts placed in a bin clearly marked for rejects?
- Does the reject bin location prevent mixing with in-specification parts?
Before: Does the operator perform all necessary process checks for error-proofing, torque gun and scanner validation, documenting the results at the beginning of each shift?
- Did the operator conduct and document error-proofing verification at the beginning of the shift?
- Did the operator check the torque gun at the beginning of the shift and record the results?
- Did the operator conduct and scanner validation checks at the start of the shift?
Beyond just the financial value of reducing defects, LPAs help organizations build a culture of quality, engaging the team in fast, value-added audits that take place every day. And while many companies are turning to automation to simplify the administrative burden of scheduling, tracking and managing follow-up for audits, one thing that can’t be automated is the questions themselves. As with many elements of quality management, a generic approach will only yield generic results. To achieve the types of drastic gains achieved by leading suppliers, you’ll have to invest time in making questions thoughtful, straightforward and detailed enough to yield meaningful answers.