The global demand for superior-quality products and services has companies increasing their focuses on core competencies. There is pressure to reduce cycle times and costs and improve quality. The outsourcing of noncore business functions that do not directly contribute to product design, development, production and delivery is an effective solution. Calibration of test and measurement equipment is one of these routinely outsourced functions. Proper calibration plays a critical role in product quality and improved compliance and ultimately a company’s reputation and success.

Objective evaluation of calibration suppliers is very important, but it can be tricky. The calibration industry is not regulated and there is no legal definition as to what constitutes a valid calibration. As a quality professional, it is your job to select and qualify your suppliers.

To do this, a thorough understanding and analysis of one’s needs is required to maximize quality and minimize the risk of making uninformed decisions.

Consider the following criteria when establishing a selection process:

Legal and regulatory requirements—Are there specific requirements the product must meet in order to be released to market? Identify these needs and include them as part of the calibration supplier evaluation process.

Quality management system—Does the quality management system require use of an ISO 9001: 2008 registered and ISO/IEC 17025-2005 accredited provider? Do customers require compliance to other standards, such as ANSI/NCSL Z540-1-1994 or ANSI/NCSL Z540.3-2006?

It is a wise choice to consider accredited suppliers, yet it is not a guarantee of service quality. Like any industry, not all suppliers are equal in the quality of services delivered. Diligence on a manufacturer’s part is critical in identifying and understanding the differences.

World-class calibration providers will happily provide a detailed presentation of their quality system, calibration methodologies and technical capabilities and limitations. Also know that with accredited calibration providers, there is oversight protection through their accrediting body. Periodic audits of a supplier—along with an understanding of the remedies available at those times when quality of service is called into question—are strong pillars with which to build a supplier assessment and selection process.

Technical requirements—What capabilities of measurement does the test equipment have? All ISO 17025 accredited laboratories have a technical scope of capability that is publicly available. A comparison of needs to a potential provider’s scope is a must.

Turnaround time requirements—Are turnaround requirements defined? Turnaround time, or equipment downtime, can be a significant component in cost evaluation. Establishment and agreement of clear delivery expectations will make management of suppliers that much easier.

Calibration methodology—Ask potential calibration suppliers about the methods they will use to calibrate test equipment. Ask for examples of procedures and any datasheets they may potentially use. If they say these are proprietary documents, then request a visit to their facility to review the documents in-person. Ask if the companies are performing a full calibration or if they are merely verifying measurements.

Ask if adjustments are performed on out-of-tolerance during the calibration event and if that is included in the calibration cost.

If a calibration supplier performs his service on-site but must take his equipment back to his lab and charge extra to properly calibrate the equipment that may warrant further review. It certainly would affect turnaround time and cost.

Automation and calibration program management—Ask suppliers about their abilities to help simplify and manage test equipment services and improve audit compliance. Do they offer online real-time access to equipment status? Do they offer systems to track asset histories, calibration certificates and data sheets?

Price—Managing supplier costs is important and pricing calibration services is complex. Deciding on suppliers based on their price alone can be very costly and damaging. Poor calibration quality can result in the recall products that have already shipped and can lead to unexpectedly high warranty costs. These problems can create serious doubt in the customers’ minds about a manufacturer’s ability to deliver a quality product.



As a quality professional, you have specific responsibilities to both your company and your customers to continually seek ways to reduce costs, ensure quality and improve product reliability. An informed decision-making process in the selection of calibration service providers will go a long way towards meeting those goals.