Validation of Inspection Methods
When you are monitoring and measuring critical dimensions for a purchased component, it is critical to ensure that your own inspection methods are valid. Even if a calibrated device can measure to a precision of 0.0001 inches, the method of measurement may be inconsistent. Two inspectors may get different results for the same part, or the same inspector may not get the same result twice when re-measuring parts. Therefore, you need to validate your inspection methods prior to approving inspection work instructions.
One of the most common tools for validating inspection methods is to perform a gauge R&R (repeatability and reproducibility) study. Repeatability is determined by having an inspector measure multiple parts of a known dimension. Typically, ten parts are used and the person repeats the measurements three times. This provides a total of 30 measurements, and the variation from the known dimensions is used to quantify repeatability. Reproducibility is then assessed by repeating the study with two other inspectors. This demonstrates the effect upon measurement results due to minor variations in technique. Gauge R&R studies are time consuming, but if your measurement process is not consistent, any trend analysis will be a waste of time.
Supplier Auditing and Remote Auditing
The most time-intensive tool for evaluating suppliers is the supplier audit. However, most supplier audits are limited in three ways:
- The audit is typically only one day in duration
- Auditors focus too little time on production process controls
- Companies do not use remote auditing techniques enough
The first limitation to supplier audits is due to the limited availability of resources for both companies—you and your supplier. However, if you are going to conduct one-day audits of suppliers, you need to make every effort to schedule multiple supplier audits near the same airport in order to minimize the travel costs associated with each audit.
Your supplier quality team might consider auditing potential new suppliers that are near existing suppliers during auditing trips, as well. Two suppliers per trip should be the minimum, unless no other suppliers can be identified in the same region.
Most medical device suppliers are ISO 13485 certified and therefore, these companies are routinely audited to that standard. However, contract manufacturers are not inspected by FDA routinely. Therefore, the weaknesses in a supplier often lie in the area of compliance with 21 CFR 820 that are slightly different from ISO 13485.
Suppliers are also accustomed to auditors spending much of their time in a conference room requesting a predictable list of procedures. In order to get the most from your limited time at a supplier, you may want to spend most of your time in production areas and request a list of quality records to be sent to you to review remotely after the on-site portion of the audit is completed.
Remote auditing techniques are relatively new, and few auditors have formal training on remote auditing. In fact, the ISO 19011:2011 guidance document only mentions remote auditing in a table in Annex B.
If your company wants to make greater use of remote auditing, emphasize that any activity that you can do in the supplier’s conference room can also be performed using interactive web-based tools, such as Skype, WebEx and GoToMeeting. Even a simple conference call and emails can replace 99 percent of the auditing activities that occur in your supplier’s conference room. What you can’t see remotely is how many people are actually doing what their paperwork says.
How will you know if your controls are working?
You can implement all of the above ideas, but the goal of supplier quality management is problem prevention—not problem correction. In order to prevent problems, you must be able to predict future supplier performance. Therefore, integrate statistical analysis into your supplier qualification process and use the quantitative results to direct continuous improvement of your supplier controls. If your supplier controls are effective, you will identify potential quality problems before you receive any nonconformity product.
Medical Device Academy