How to Increase Production and Improve Quality in the Calibration Laboratory

Source: Edison ESI, a Southern California Edison (SCE) Company
The continuing evolution of quality requirements presents significant challenges for today's calibration laboratories. Where traceability was once the only basic requirement a calibration laboratory must adhere, there are now numerous accrediting bodies, quality programs, regulatory agencies and auditors to which the metrology community must satisfy. As technological breakthroughs become the norm rather than the exception, the very science of measurement becomes more demanding. Simple sets of measurements are no longer adequate; Measurement Uncertainties, Statistical Process Control and parametric data analysis are now requirements for many metrology customers. Add to this the corporate demands for more productivity and higher profits, and any calibration facility, no matter how competent, must now prepare to address the myriad of challenges for higher quality and increased productivity. This is the how one calibration laboratory identified and solved these challenging issues.

The Challenge
How does the calibration lab cope with juggling so many expectations and remain both viable and profitable? How can the lab's processes address such varied disciplines, answering the needs of its clients, management, administration, calibration technicians, quality and engineering? What method can be used to effectively collect and store the calibration data for historical parametric data analysis? How can the calibration lab analyze measurement uncertainty in a practical and profitable manner?

First Hand Experience
Edison ESI Metrology Laboratory experiences these challenges and provides solutions that can be applied across the metrology industry. Our Laboratory was designed and constructed in 1987 to support the metrology requirements of the Southern California Edison Company nuclear and conventional electric power generating stations but has expanded over the years to include commercial clientele from the diverse and burgeoning industries in our region and across the country. This modern 23,000 sq.ft. facility encompasses fifteen environmentally controlled laboratories. It is staffed and equipped to perform calibrations for a broad spectrum of metrology disciplines. Our customer base of over 400 clients provides unique opportunities to hone our processes and sharpen our productivity. Through many years of continuous improvement, we have developed Quality Systems and Metrology Software Programs that help us maintain the highest level of quality and productivity in our calibration laboratories.

In recent years, we realized that consistently meeting calibration technical and quality requirements while reducing costs and turn times, in addition to providing adequate controls over our processes with a minimum of management and engineering personnel, could only be accomplished with a state-of-the-art software system based on collection and analysis of calibration data. We required a single system that could be used in all metrology disciplines. The system needed to collect calibration data both manually and through automation; facilitate conformance test decisions, have access to information, specifications and procedures; analyze calibration intervals and uncertainties; maintain records, produce reports, maintain traceability, and assess the impact of calibration failures; i.e., to effectively manage the calibration process, using one seamless, rapidly executing system. Quality and production were of utmost importance. The system had to meet stringent quality requirements for Nuclear, Pharmaceutical, Biomedical and Aerospace industries. In addition, it must improve the overall quality and quantity of our production.

The Solution
The solution to these complex and multifaceted issues can quickly become an overwhelming task. An investigation into commercially available software was launched. We evaluated several well-known software packages and found that although they did an adequate job for their limited scope, they lacked the flexibility and interoperability required for a high production, multi-disciplined laboratory; some even failed to address critical quality requirements of ISO/IEC 17025, 10 CFR50 Appendix B and 21 CFR Part 11. Although we found some are good at information management and others with computer controlled equipment or uncertainty analysis, none adequately address all pertinent technical issues required for producing the laboratory's principle product, the Report of Calibration.

How for example; can a laboratory that performs more than 20,000 calibrations per year stop and analyze measurement uncertainty each time or ensure 4-to-1 ratios are met, or apply conformance test decision rules or other customer mandated requirements, or even compare its own results with those produced last time and do it effectively and efficiently, without a process with some or all of these features built-in? We concluded that attempting to control the calibration process with words and specifications written in procedures was not the best approach and that it was time for us to move to a data base environment. We found that the best approach to addressing these issues was to design and develop our own system that incorporates multiple software tools for meeting these requirements.

Over the course of several years, our team of Metrologists and Engineers developed a system that would build upon our existing Laboratory Information Management System (LIMS), yet could also be used independently. The system was designed to satisfy the quality requirements of 10 CFR 50 Appendix B, ISO/IEC 17025, ISO-9002, GMP 820.60 and 21 CFR Part 11 and others. Moreover, the system was designed to significantly enhance our production, in both quality and quantity.

The concept of the new metrology system was divided into three basic components or tools. These tools were specifically designed for Calibration, Engineering and Management. Together they comprise the set of Metrology Tools we call MUDCATS Calibration Process Manager, Professional Edition. This system was intentionally designed for interoperability with our existing software and those available elsewhere, and to allow personnel with appropriate levels of access to tailor or configure virtually any part of it to meet individual laboratory, program and customer requirements.

The foundation of MUDCATS is comprised of an Equation System, Intelligent SI Units Interpreter and SpecTrack a Standards Specification Library. The workhorse of mathematical operations or math engine is the Equation System that uses standard operands, a function library, and user defined variables. Units of measure when specified on a data sheet, are recognized and interpreted by the Intelligent SI Units Interpreter, and automatically converted between the Unit Under Test (UUT) and selected calibration standard as required.

SpecTrack is a unique specification library that maps the accuracy and/or uncertainty specifications of instruments, including calibration standards. Instrument accuracy specifications are entered through a unique user interface that provides a systematic, logical architecture for building specification data. Specification data stored in SpecTrack is used throughout MUDCATS in the calculation of Estimated Measurement Uncertainty (EMU), Test Accuracy Ratio (TAR) and for failure analysis. SpecTrack enables MUDCATS to assign calibration standards and their related function, range and accuracy specifications to data sheets. SpecTrack specifications are integrated into the data sheet when the applicable standard is applied. Upon standard(s) selection, MUDCATS automatically calculates TAR and EMU for each calibration test point. Significant advancements are gained through traceability at the UUT and Standard test point level. Users can perform failure analysis and reverse traceability for each test point level.

Calibration Tools
The basic function of the Calibration Tools was to facilitate the translation of equipment specifications into electronic data sheets. These electronic data sheets are used to collect and store calibration data and for reporting purposes. We have developed an extensive library of datasheets covering most commonly calibrated Measuring and Test Equipment (M&TE). As test point data is being collected, MUDCATS indicates the degree to which an instrument is in or out of tolerance (OOT), and displays an appropriate color-coded flag. Automation scripting can be added to data sheets to configure instruments, capture data, perform mathematical operations, communicate with external software, and even create instrument test points dynamically. Once created and approved, data sheets are controlled under MUDCATS document control provisions.

MUDCATS provides for calibration of up to eight instruments simultaneously. Each independent channel has a display module for "As Found" and "As Left" data. Channels can be edited, saved, and printed individually. Data is entered using a keyboard, QuickData keypad or via automation control.

The Data Sheet Designer allows data sheets to be quickly and easily created and edited. Formatting data is completely automatic. MUDCATS makes data sheet creation almost instantaneous with a full complement of software wizards. Custom data sheets can easily be created using the Data Sheet Generation Wizard. For example, the Automatic Pressure Data Sheet Generation Wizard prompts the user for pressure gauge specification data, and then generates an entire datasheet automatically.

Automation scripting commands can be added to any row of a new or pre-existing data sheet without the need for instrument drivers. MUDCATS can interface with virtually any instrument that has GPIB or RS-232 communication capability. Scripting data sheet rows independently allows direct interaction between commands and test point data, allowing command sets to be run as groups.

The Integrated Tolerance Calculator allows the data sheet designer to generate single or multiple test point row data by merely entering nominal test point values and equipment specification data. Intricate tolerances can be expressed using the Custom Tolerance Calculator to calculate tolerances based on specification components that are more complex than standard specification components.

Wizards make data sheet test point generation quick, easy and uniform. MUDCATS provides a special set of tools that allows custom wizards to be created with the Wizard WorkShop. The Wizard WorkShop permits predefinition of test point values, tolerance format, function tested descriptions, and data sheet boilerplate information. A single data sheet wizard can contain multiple test point definitions for various functions.

Engineering Tools
The Engineering Tools focus on Measurement Uncertainty and analysis of parametric data. Both are essential elements of quality and statistical control.

Calculation of Measurement Uncertainty in compliance with ISO/IEC 17025 is mandatory for today's calibration laboratories. Section of this standard states that "A calibration laboratory ... shall have and shall apply a procedure to estimate the uncertainty of measurement for all calibrations and types of calibrations." In addition, section states, "when statements of compliance [with a specification] are made, the uncertainty of measurement shall be taken into account." Also, that "when a statement of compliance ... is made omitting the measurement results, the laboratory shall record those results and maintain them for future reference."

MUDCATS reduces the overwhelming task of complying with today's stringent requirements for recording of data and evaluating and reporting of measurement uncertainty. MUDCATS automatically calculates each test point's Test Accuracy Ratio (TAR) and Estimated Measurement Uncertainty (EMU) when a calibration standard(s) is assigned to the data sheet. Utilizing the SpecTrack specification library, MUDCATS interprets Units of Measure and synchronizes the UUT and Standards test parameters, transforming them to account for what typically are the most prevalent sources of error. Estimates of measurement uncertainty and test accuracy ratio are developed using guidelines from ANSI/NCSL Z540-2-1997, U.S. Guide to the Expression of Uncertainty in Measurement (GUM), Type B methods, and are optionally reported to the customer.

Further sources of error can be incorporated through utilization of MUDCATS exclusive Measurement Uncertainty Wizard. The Measurement Uncertainty Wizard allows us to develop Type A or Type B uncertainty budgets for individual test points in addition to those automatically accounted for by the EMU algorithm. Components of EMU may also be selectively included or disabled. Once EMU is established, it can be accounted for by varying the point at which the OOT flag is raised, thus eliminating the need to apply guard bands to calibration tolerances or to take other compensating measures.

Instrument failures are analyzed with the Instrument Range Utilization Report. This report enables our engineer to automatically evaluate out-of-tolerance conditions by tracking the function, range and test point information between each standard utilized and the unit under test. Traceability is maintained from the specific standard's function and range through the UUT-specific test point. The report identifies each UUT and test point(s) affected by the standard's failed range.

Instrument trends are analyzed using the historical data plotter. This invaluable tool enables Metrology Engineers to view parametric "As Found" and "As Left" calibration test point data by Asset ID or data sheet family within a given time frame. Out-of-Tolerance trends can be readily identified and adjustments to instrument specifications or intervals can be recommended with confidence.

Drift Analysis enables us to plot data and analyze trends in laboratory standards and client M&TE between calibrations, on a test point by test point basis. The optional Drift Analysis Module allows plotting of data, identification of trends and calculation of basic statistics. Ultimately, this tool will enable the laboratory to establish the uncertainty of its standards and client's M&TE (when requested) in real time, in order to determine optimum calibration intervals.

Management Tools
Complete control of the calibration system is frequently required by industry quality standards or for regulatory compliance. MUDCATS incorporates a comprehensive security system to safeguard data and limit system access to only authorized users. Various levels of permissions can be granted for individual users within the closed system. Login rules further define user access for number of log in attempts, and automatic user inactivity log outs.

MUDCATS employs sophisticated controls designed to ensure compliance to 21 CFR Part 11, including the authenticity and integrity of electronic records. Automatic, computer generated, time-stamped audit trails are utilized to independently record the date and time of operator actions that create, modify or delete records within MUDCATS. Authority checks further ensure that only authorized individuals can log into MUDCATS, save calibration records and approve new or revised calibration data sheets. Audit trails are printed and reviewed by authorized personnel for transaction details and data integrity.

Calibration data sheets and subsequent revisions are maintained and controlled through MUDCATS' exclusive Data Sheet Revision Control process, in accordance with ISO/IEC 17025 Section 4.3.1 Document Control, states in part: "The laboratory shall establish and maintain procedures to control all documents that form part of its quality system, such as…test and/or calibration methods..."

Data sheets are signed, time and date stamped for approval by the authorized individual. Previous data sheet revisions are inactivated, yet maintained in the system for historical documentation archival.

MUDCATS incorporates an automated Catalog System of all data sheets and calibration records. The catalog is used to locate and select a data sheet or a calibration record. The data sheet catalog can be searched by model, manufacturer, and equipment description or calibration procedure.


Increases in Productivity:
o Reduced calibration time by 30% or more.
o Calibrate new equipment quickly
o Reduce turnaround time
o Increased laboratory capacity
o Enhanced flexibility for all disciplines
o Incorporation of calibration instructions
o Interface with virtually any instrument
o Provides wizards for faster development

Improvements in Quality:
o Meets or exceeds applicable quality requirements
o Provides controlled, secure system
o Controls data sheet revisions
o Maintain data sheet consistency
o Reduce or eliminates transcription errors
o Automatically determines Pass/Fail status
o Retains all calibration data securely on-line
o Provides standards specification library
o Incorporates standard SI Unit converter

MUDCATS Calibration Process Manager is an exceptional new metrology software tool that compliments and enhances our existing laboratory management system. MUDCATS works in quality, engineering, at the bench, and in the field to simplify and accelerate the calibration process. MUDCATS was designed and developed to satisfy quality requirements of ISO/IEC-17025, 10 CFR 50 Appendix B, ISO-9001 and GMP 820.60, relating to the creation, management, and automation of calibration data sheets and data collection. MUDCATS is a fully integrated software system that manages the complete calibration process. We have installed it on a network server and on stand-alone PC workstations or laptops. MUDCATS also provides an optional portable module that can be used on a notebook PC for use in the laboratory or field locations.

Due to the unprecedented success enjoyed in applying MUDCATS Calibration Process Manager in our own laboratories and our belief in its potential and broad applicability in our industry, we have decided to market this product commercially. Our goal is to continue to enhance and improve MUDCATS though feedback from our own laboratory and our clients. We will strive to extend its capabilities to more technically complex calibrations via interface with some of our existing software tools and those currently under development. We will also strive to maintain a completely open architecture to give this product the widest compatibility with existing Laboratory Management Systems. In fact, we find that MUDCATS starts where these other systems leave off.

MUDCATS Calibration Process Manager has undergone extensive and rigorous system testing and qualification to ensure the integrity and confidence of the system. A qualified, independent software compliance provider accomplished verification and validation of the system. Overall, what started out, as a search for calibration solutions for a specific laboratory has become a revolution in data collection and calibration process management. For more information, please go to, or call toll-free at 866-723-2257.

Source: Edison ESI