| by Paul Bessette and Mark Dillard
High-quality products and services
at competitive prices are the norm in today’s fiercely
competitive global marketplace. In order to stay in business
while delivering both quality and value, companies often
find themselves looking for ways to reduce costs and free
up valuable resources. One way to do so is outsourcing difficult-to-manage
functions that lie outside core processes; calibration services
frequently fall under this category.
Usually it’s the quality professional’s responsibility
to select and manage calibration suppliers--as economically
as possible. The overall cost of this process can be trimmed
considerably if, before talking with prospective suppliers,
you clearly define your organization’s requirements
through supplier evaluation criteria.
Prior to establishing calibration supplier-selection criteria,
it’s important to clearly define your requirements.
Some areas to consider include:
ndustry quality standards and requirements dictated by customers
and regulatory bodies. For example, automotive industry
suppliers must establish a calibration program driven by
QS-9000 or ISO/TS 16949, whereas pharmaceutical suppliers’
programs are guided by FDA regulations.
Organizational requirements. For example, do you require
electronic invoicing?
Department-specific requirements. A shorter calibration
turnaround might be required for a production line running
24 hours a day than for an engineering department that uses
its equipment less frequently. Understanding each department’s
requirements and communicating them to the calibration supplier
will result in fewer problems and a lower cost to manage
the program.
Only after you’ve determined your calibration requirements
can you develop effective supplier-selection criteria. Key
factors for minimizing the total cost of a calibration program
include a sound assessment of the supplier’s:
Quality system
Technical competence (of both measurement results and technicians)
Automated calibration procedures
Financial stability
Service delivery methods
Record access
Turnaround time
Ability to meet your needs
Quality requirements provide the best means of determining
which calibration provider meets your needs. A fully documented
and technically capable lab will have established a quality
system that includes both an ISO standard registration and
ISO/IEC 17025 accreditation. Choosing a lab that has one
without the other exposes your company to potential service
risks and increased costs.
ISO 9001:2000 ensures that a quality system is defined,
documented and followed but doesn’t require procedures
for monitoring a lab’s technical ability or assessing
how well its technicians perform tests or calibrations;
for that, you must look for ISO/IEC 17025 accreditation,
which ensures that a lab will perform calibrations as stated
on its scope of accreditation.
ISO/IEC 17025 auditors can provide independent, professional
assessments of a calibration lab’s technical ability.
Because scopes of accreditation vary, it’s important
to compare them when assessing several labs. Some offer
very little capability and, just to claim accreditation,
will list a few low-accuracy items on their scopes of accreditation.
This won’t ensure the lab’s technical quality
when performing calibrations that require higher accuracies
than those listed. One must also pay attention to who accredited
the lab. Many ISO 9000 registrars accredit laboratories
to ISO/IEC 17025, and it’s prudent to verify that
the accreditation is recognized in your industry and by
your customers.
Obviously, your potential service provider’s technical
competence is critical, but it’s often difficult to
assess. “Technical competence” should imply
technically valid measurement results as well as competently
trained metrology technicians. If you’re not a metrologist,
the best way to assess a supplier’s technical ability
is to check its respective ISO/IEC 17025 scopes of accreditation.
The technicians’ qualifications and experience are
critical to ensuring good metrology practices, valid calibrations
and confidence in the measurement results. Technicians should
have broad knowledge and technical ability within their
particular lab area. Verification that they’ve completed
either of the following two programs can help assess calibration
technicians’ competence:
Previous military training in precision measurement equipment
or TMDE technician programs. Technicians under this program
receive formal classroom instruction and extensive on-the-job
experience calibrating test equipment.
American Society for Quality Certified Calibration Technician
program. The ASQ certification covers six main areas of
expertise: general metrology; measurement systems; calibration
systems; applied mathematics and statistics; quality systems
and standards; and uncertainty.
Although formal military training or ASQ certification
doesn’t guarantee appropriate calibration of your
instrumentation, it does ensure the technician has fundamental
knowledge of calibration. Should measurement discrepancies
occur, the technician will know the calibration process
well enough to ascertain whether the discrepancies are associated
with the device under test, the setup or the standards used
in the calibration process. Erroneous readings can make
an instrument read out of tolerance when it’s in tolerance
or vice versa. Inexperienced technicians with little or
no proper training often overlook errors associated with
their own standards and setups. These errors can create
problems for the customer, including product recall or wasted
time and labor reviewing out-of-tolerance conditions that
don’t actually exist.
Calibration laboratories often use a commercial calibration
program or develop their own automated software procedures.
In the former case, the responsibility for reliable validation
and testing usually falls upon the software manufacturer.
If the lab writes an automated calibration software program,
it must validate the procedure before implementing it. Software
validation is a critical process that ensures the validity
of results. Without this control, data results provided
to a customer can be skewed, incomplete or even incorrect.
The following should be defined and documented when validating
a software procedure:
Software requirements
Design, including architecture, construction code, source
code and any annotations
Test plan to ensure that software input and output obtain
the expected results (i.e., just as if the calibration had
been performed manually)
Installation and checkout documentation
Traceability matrix showing how the requirements map to
the design test
A lab’s financial stability is important. When looking
for a suitable calibration supplier, consider the company’s:
Viability. Will the lab be around for the next calibration?
Reliability. Will it keep pace with your organization’s
technological advances?
Flexibility. How will it manage changes in scope in a constantly
changing environment?
Inadequate financial stability and resources could result
in excessive turnaround times, inadequate calibrations or
simple lack of support, all of which will affect your product’s
delivery time and quality.
Methods for providing calibration services include pick-up
and delivery from fixed calibration lab locations, scheduled
on-site calibrations, permanent on-site calibrations (e.g.,
installing technicians, processes and tools at your location)
and ship-in/ship-out services. Some companies also use self-contained
mobile labs to provide scheduled on-site calibration. Working
with your provider to determine which delivery method is
most compatible with your needs will result in lower program
management costs for your company.
Calibration records (e.g., certificates, reports and measurement
data) are often provided with the instrument either as hard
copy or electronic media. Many providers also offer real-time,
online record access for calibration records and invoicing
through their Web site. Online access reduces time spent
filing paperwork, allows for easy access of specific documentation
such as calibration certificates and frees up floor space
previously relegated to record storage.
Important record factors to evaluate include:
Protection and security of calibration records and information
Ease of access, backup and recovery capability
Length of record storage
Accessibility to records upon termination of contract
Real-time access to records
Some calibration providers will even e-mail monthly “calibration
due” notices to the appropriate equipment user. All
of these options can help you maximize your calibration
program’s efficiency and reduce internal costs.
Downtime for calibration can be a costly risk. During
the last several months, many businesses have lacked capital
for investing in test equipment, and consequently, they
must keep what equipment they do have running optimally.
The industry standard for instrument turnaround time is
five business days, but most service providers, if requested,
will offer expedited service for critical items. Expedited
services often cost more, so it’s best to check with
the calibration provider to determine costs. Turnaround
times are often linked with the provider’s financial
stability. The greater the provider’s stability, the
greater its ability to ensure that labor, equipment and
resources are available when needed.
Differentiating the varied services offered by calibration
labs can help you narrow your choices to the provider that
best meets your needs. For a list of characteristics of
some calibration service providers, refer to the table posted
at www.qualitydigest.com/pdfs/0803cal.pdf. Depending upon
your organization’s size and needs, each of them has
something valuable to offer.
Too often, companies focus solely on the price a supplier
charges for calibration service and overlook the total cost,
which includes the previously mentioned evaluation elements.
An arbitrarily selected calibration service provider could
disastrously affect your organization, but an informed choice
will benefit quality, customer relations and that all-important
bottom line.
Paul Bessette is quality manager and staff metrologist
at Sypris Test & Measurement. Bessette has held other
metrology and management roles in the U.S. Air Force PMEL
and for Unified Industries in Springfield, Virginia; Martin
Marietta in Orlando, Florida; Guildline Instruments; and
Detroit Edison.
Mark Dillard has more than 20 years of experience
providing customized metrology service solutions. Dillard
is director of sales and marketing at Sypris Test &
Measurement. Letters to the editor regarding this article
can be sent to letters@qualitydigest.com.
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