NIST-ASME workshop on uncertainty in dimensional measurements. (Conference Report).Gaithersburg, MD
June 5-7, 2001.
While the use of measurement uncertainty in dimensional measurements, particularly uncertainty represented according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. the ISO (1) See ISO speed.
(2) (International Organization for Standardization, Geneva, Switzerland, www.iso.ch) An organization that sets international standards, founded in 1946. The U.S. member body is ANSI. Guide to the Expression of Uncertainty in Measurement (GUM), is a wellestablished practice among national metrology institutes (NMIs), is a required basis for commercial laboratory accreditation, and is being specified in international product standards, such use is rare in U.S. industry and problematic where used, being unsupported by documentary standards that could provide specific practical guidance. To help address the problem, Special Committee H213 of the Board of Standards of the American Society of Mechanical Engineers (body) American Society of Mechanical Engineers - (ASME) A group involved in CAD standardisation. (ASME ASME - American Society of Mechanical Engineers ) and the Manfacturing Engineering Laboratory of the National Institute of Standards and Technology National Institute of Standards and Technology, governmental agency within the U.S. Dept. of Commerce with the mission of "working with industry to develop and apply technology, measurements, and standards" in the national interest. (NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. ) co-sponsored the workshop which this report describes. The conference organizers were: Dr. Gregory Hetland, Hutchinson Technology ''This article or section is being rewritten at
Hutchinson Technology is an acknowledged world leader in precision manufacturing. Specializing in design and manufacture of close-tolerance products that require chemical, mechanical and electronic technologies. Incorporated; Dr. Jay Raja, University of North Carolina North Carolina, state in the SE United States. It is bordered by the Atlantic Ocean (E), South Carolina and Georgia (S), Tennessee (W), and Virginia (N). Facts and Figures
Area, 52,586 sq mi (136,198 sq km). Pop. , Charlotte; and Dr. Dennis Swyt, NIST, who acted as conference moderator.
2. Purpose of Workshop
The purpose of the 2 1/2 day workshop was two-fold. The first purpose was to inform participants on trends and problems associated with the use of measurement uncertainty in industrial applications from a variety of perspectives, particularly problems addressable Reachable. When something is addressable, it can be identified and manipulated independently of its surroundings. For example, screen pixels and RAM memory are addressable. Each of the screen's picture elements can be individually turned on and off, and each of the memory's bytes can be by documentary standards-based recommended practices. The second purpose was for participants to develop recommendations, particularly to the documentary standards community, on potential solutions to identified problems.
3. Participants of the Workshop
The intended audience for the workshop was industrial and laboratory metrologists, engineers, and managers with interests in the use of statements of uncertainty for results of dimensional measurements for any purpose. Notification of potential attendees was via NIST's conference announcement process, the NCSL-I (1) newsletter, and a broad mailing to membership lists of ASME standards committees, the American Society for Precision Engineering, and NIST dimensional calibration customers. Fifty-six persons from the following organizations participated in the workshop:
A2LA A2LA American Association for Laboratory Accreditation
Pratt & Whitney
S Cal Edison
UNC (Universal Naming Convention) A standard for identifying servers, printers and other resources in a network, which originated in the Unix community. A UNC path uses double slashes or backslashes to precede the name of the computer. Charlotte
US Air Force
Wyle Laboratories Wyle Laboratories, Inc. is a privately held provider of specialized engineering, scientific and technical services to the Department of Defense, NASA, and a variety of commercial customers primarily in the aerospace industry.
4. Structure of Workshop
The workshop was structured to provide participants with reports on practices and problems in the use of uncertainty in dimensional measurements and an opportunity to make recommendations on potential solutions to the problems identified. The first day was devoted to presentations on practices and problems in the use of uncertainty in dimensional measurements from different points of view. The following list shows the topic, speaker, and affiliation for each of the 12 presentations:
U.S. national documentary J. Salsbury Hutchinson Technology Measuring-instrument J. Salsbury Mitutoyo supplier Aircraft manufacture B. Parry Boeing Auto manufacture J. Fallert Daimler-Chrysler Computer equipment J. Buttress Hutchinson Technology manufacture Microelectronics R. Scace NIST/OMP manufacture Industry standards K. Jaeger NCSL-I laboratories International documentary T. Charlton ASME H213 U.S. national documentary T.Estler NIST/ASME B89.7 standards National Measurement J. Decker NRC-Canada Institute R&D on coordinate S. Phillips NIST metrology Laboratory accreditation S. Doty NVLAP VIM-GUM T. Estler NIST/JCGM
The second day of the workshop was devoted successively to breakout sessions for identification of problems in the use of uncertainty in dimensional measurements, a plenary session Plenary session is a term often used in s to define the part of the conference when all members of all parties are in attendance.
These sessions may contain a broad range of content from Keynotes to Panel Discussions and are not necessarily related to a specific style of delivery. for review of problems identified, and breakout sessions for development of proposed solutions to problems. Breakout sessions were facilitated by T. Estler, J. Kramar, S. Phillips, J. Stoup, and D. Swyt of NIST. The third (half) day was devoted to plenary-session development of rank-ordered recommendations on problems identified, including follow-up actions for individual workshop participants.
5. Results of Workshop
The following are the seven resulting rank-ordered statements of identified problems, proposed solutions, and recommended actions to be coordinated by ad hoc For this purpose. Meaning "to this" in Latin, it refers to dealing with special situations as they occur rather than functions that are repeated on a regular basis. See ad hoc query and ad hoc mode. workshop follow-up committee lead by workshop organizers.
5.1 Steering Group to Lead in Measurement Uncertainty Education
Problem: While (1) international standards bodies Following are some of the standards bodies defined in this database. For Windows users of CDE, look up Lessons/Review/Associations. For Web users of CDE's online HTML version, review the Lessons list at the bottom of the definition.
Organization Covers ANSI U.S. are developing specifications requiring use of measurement uncertainty, (2) domestic manufacturers anticipate growing need for their use and (3) calibration laboratories seeking accreditation must use them to establish required traceability, manufacturers point to the lack of a body of people who are trained to understand and knowing how to use uncertainty as these specifications require. Laboratories, on the whole, are afraid of the term "uncertainty budget" because they do not know how to do calculate one, and educators note a lack of easily accessible resource materials to educate properly current and future practitioners in measurement uncertainty. Further, while virtually everyone, from NMI (NonMaskable Interrupt) A high-priority interrupt that cannot be disabled by another interrupt. It is used to report malfunctions such as parity, bus and math coprocessor errors.
NMI - Non-Maskable Interrupt to industrial practitioner, needs to produce statements of uncertainty, many do not understand the instruments and measurement processes well enough and do not have the resources to acquire the understanding needed to do so. In addition, no single entity has overall re sponsibility for the problems of "training and education" in the area of uncertainty in dimensional measurements.
Solution: Under the leadership of an ad-hoc steering group:
* Establishment of a group (possibly composed of high-level managers from industry, government agencies, and universities) with the mission to promote the long-term sustainable educationa efforts in the use of uncertainty in measurements, particularly dimensional measurements.
* Establishment of a group (possibly within ASME B89.7, NCSLI NCSLI National Conference of Standards Laboratories International , NIST, or universities) with the mission to catalogue currently available educational resources for uncertainty issues.
* Development of an "educational framework," that is, a comprehensive vision and scheme for education in measurement uncertainty, covering
what needs to be known (general: statistics, cost/benefit ratios, VIM/GUM, metrology, geometric dimensioning and tolerancing Geometric dimensioning and tolerancing is a symbolic language used on engineering drawings and computer generated three-dimensional solid models for explicitly describing nominal geometry and its allowable variation. It is often referred to by the abbreviation, GD&T. , mathematics, physics; industry-specific: heavy manufacturing, light manufacturing, precision manufacturing, semiconductor, electrical)
who needs to know it (practitioners, assessors, financial managers, technical managers, NMIs, researchers, customers)
who will fund it (NSF NSF - National Science Foundation , NIST, DOE, DOD (1) (Dial On Demand) A feature that allows a device to automatically dial a telephone number. For example, an ISDN router with dial on demand will automatically dial up the ISP when it senses IP traffic destined for the Internet. , CCG CCG Chicago
CCG Collectible Card Game
CCG Canadian Coast Guard
CCG Country Commercial Guide
CCG Children's Cancer Group
CCG Commission Canadienne des Grains (Canadian Grain Commission) , SME (1) (Small and Medium-sized Enterprise) See SMB.
(2) (Subject Matter Expert) An individual who is well-versed in the policies and procedures of a particular department or division. , ASQ ASQ American Society for Quality
ASQ Arab Studies Quarterly
ASQ Automated Software Quality
ASQ Administrative Science Quarterly
ASQ Ages & Stages Questionnaires
ASQ Allowable Sale Quantity
ASQ Ascension Island (DoD radar) , industrial consortia, students, industry lobby groups)
how it can be provided (self-paced learning, commercial training classes, websites, free modules for university training)
who will provide it (vendors, consortium of universities and national labs, professional societies, companies)
when it should be provided (high school instructions through bridge programs/internships; post-secondary education; vocational/trade schools, junior colleges, universities, just-in-time training, continuing education continuing education: see adult education.
or adult education
Any form of learning provided for adults. In the U.S. the University of Wisconsin was the first academic institution to offer such programs (1904). )
how it will be validated/certified (multi-level certification by professional societies, e.g., ASME, SME, NCSLI, SAE sae abbr (BRIT) (= stamped addressed envelope) → sobre con las propias señas de uno y con sello , AMTMA AMTMA American Measuring Tool Manufacturers Association , ASQ, vendors, colleges, universities).
5.2 Consortium Devoted to Meeting Industrial Needs in Measurement Uncertainty
Problem: The cost-burden on individual, especially small, companies is too great (at this time) for them to support the development of education, training, communication, and standards-development infrastructure needed to effectively and promptly address the wide range of such problems in the use of uncertainty in measurements, particularly dimensional measurements, facing U.S. industry today.
Proposed Solution: Establishment of an industrial consortium dealing with problems in the use of uncertainty in measurements, particularly dimensional measurements, in order to leverage dollar investments by individual members of the consortium and to pursue other sources of funding, including from Congress, the NIST ATP ATP: see adenosine triphosphate.
in full adenosine triphosphate
Organic compound, substrate in many enzyme-catalyzed reactions (see catalysis) in the cells of animals, plants, and microorganisms. Program, NSF and the like.
5.3 Website for Measurement Uncertainty Documents
Problem: While there are many documents on uncertainty in dimensional measurements, (including international and national standards, accreditation practices, and technical reports) of potential value to a broad range of possible users, these documents are scattered Scattered
Used for listed equity securities. Unconcentrated buy or sell interest. and not easily accessible to many, with no easy and efficient means by which one may find out about them.
Proposed Solution: Creation and operation by an appropriate institution of an "Uncertainty in Dimensional Measurements" web site focussed on the principal documents on the subject. Proposed features of the website include: optional registration; a hierarchy of documents; diagram of standards, and guides showing interrelationships; synopses of documents; user reviews of documents; news of upcoming round-robins; user forum; case studies; testimonials to cost savings and continuous improvement; a roadmap on developments; and a primer for neophytes.
5.4 Business-Case Justifications on Use of Measurement Uncertainty
Problem: The business community requires cost justification for allocating dollars to implement measurement uncertainty. For example, executives and managers need a basis for spending on training and devoting human resources The fancy word for "people." The human resources department within an organization, years ago known as the "personnel department," manages the administrative aspects of the employees. to support analysis and use of measurement uncertainty and purchasing agents Noun 1. purchasing agent - an agent who purchases goods or services for another
agent - a representative who acts on behalf of other persons or organizations need a basis to weigh the uncertainty versus cost in acquiring measuring instruments.
Solution: Development by ASME B89.7 of technical reports that provide business-case justification for the use of uncertainty in measurements, including
* "problem statement paper covering ROI (Return On Investment) The monetary benefits derived from having spent money on developing or revising a system. In the IT world, there are more ways to compute ROI than Carter has liver pills (and for those of you who never heard of that expression, it means a lot). opportunities" dealing with
decision rules (false rejects, false accepts)
calibration frequency extended life of measurement systems
product warranty risks quantified
improved process to achieve competitive advantage
allocation of limited resources for highest ROI (CMM (Capability Maturity Model) A process developed by SEI in 1986 to help improve, over time, the application of an organization's supporting software technologies. , lab, fixture, sampling, cleaning)
recovery of yields loss
* ROI case studies as published technical reports
ROI Case Study 1 on selecting measuring equipment (including system, room, cleaning, allocating resources; impact of required infrastructure from industrial labs to NIST; determining calibration frequency and control parameters Control parameters
In a nonlinear dynamic system, the coefficient of the order parameter; the determinant of the influence of the order parameter on the total system. See: Order Parameter. ; reducing buyer/ seller disagreement)
ROI Case Study 2 on dealing with measurement uncertainty with respect to tolerances at the design stage (including recovering yield loss through decision rules, process control and impacts of measurement, e.g., Motorola Six-Sigma Quality)
ROI Case Study 3 on Failure Mode and Effects Analysis Failure Mode and Effects Analysis (FMEA) is a risk assessment technique for systematically identifying potential failures in a system or a process. It is widely used in the manufacturing industries in various phases of the product life cycle. (Catastrophic failures A catastrophic failure is a sudden and total failure of some system from which recovery is impossible. The affected system not only experiences destruction beyond any reasonable possibility of repair, but also frequently causes injury, death, or significant damage to other, often , e.g., Shuttle Challenger, Ford-Firestone, Dodge Minivan latches, seatbelt recalls and lawsuits, scrap of high-cost products).
5.5 Accreditation-Related Standard Methods on Uncertainty
Problem: In the area of accreditation (which is defined broadly to include accreditation, certification, and auditing), there is an absence of documented standard methods related to measurement uncertainty for use by both auditors of laboratories and laboratories being audited. While many institutions--as part of a system--create, invoke, or require procedures on the use of measurement uncertainty and end-users of such procedures may have to deal with inconsistent requirements, no single institution has responsibility in the system for producing a single, self-consistent, technically-sound set of standard procedures that may be used by all.
Proposed Solution: The proposed solution is the coordinated development by ASME, NCSLI, NIST, NACLA NACLA North American Congress on Latin America
NACLA National Cooperation for Laboratory Accreditation
NACLA North American Committee on Latin America (and other institutions with shared responsibility in the area of measurement uncertainty) of documented standard methods for: itemizing and listing contributions to uncertainty that must be addressed; appropriately defining "scope of accreditation," e.g.. for coordinate metrology; evaluating the credibility of uncertainty statements; proficiency testing proficiency test n → prueba de capacitación of on-site (non-laboratory) calibrations; formatting uncertainty budgets; and demonstrating traceability in practice.
5.6 Addressing of Specific Technical Issues by Standards Committee
Problem: There is an array of problems associated with current and needed documentary standards governing the use of uncertainty in dimensional measurements, including:
The GUM, its complexity for most people to use, and its unsuitability for economic decision-making
The establishment of credibility and validity of uncertainty statements
Identification of significant input quantities
Inconsistency in reporting format
Inconsistency in terminology/vocabulary and interpretation
Decision rules connected to economics
tr.v. cal·i·brat·ed, cal·i·brat·ing, cal·i·brates
1. To check, adjust, or determine by comparison with a standard (the graduations of a quantitative measuring instrument): instruments used for unlike measur ands and/or extended conditions
Evaluation of measurement uncertainty for calibrations based on a single observation
Measurands that are insufficiently defined by some standards (e.g., ISO 1101)
Lack of consensus standards on some instrument performance specifications/tests.
* Development by the international committee responsible for the GUM (JCGM/WG1/SC4) of models for measurement uncertainty that are simple, general, and usable by industry
* Development by the U.S. national standards committee responsible for uncertainty in dimensional measurements (ASME B89.7) of documentary standards, including formal standards or technical reports, that
provide a simplification of the GUM more usable by industry than the GUM itself (B188.8.131.52)
define a basis for establishing the credibility and validation of statements of uncertainty in dimensional measurements (B184.108.40.206)
identify the significant input quantities to uncertainty in dimensional measurements (B220.127.116.11)
1. To cause to conform to a standard.
2. To evaluate by comparing with a standard. the reporting format for statements of uncertainty, uncertainty budgets, expected sources of uncertainty, and the criteria for consideration of those expected sources within the reporting format (B18.104.22.168)
provide decision rules connected to economics for the use of measurement uncertainty in, for example, determining conformity of manufactured parts or measuring instruments to specifications (B89.7.3.l)
deal with instruments that are calibrated for one measurand under one set of measurement conditions being used for other measurands and/or other conditions [see "Careful Consideration of the Calibration Concept," M. S. Levenson et al., J. Res. Natl. Inst. Stand. Technol. 106, 371 (2001)] deal with evaluating measurement uncertainty for calibrations or measurements based on a single observation (measurement), rather than repeated ones, by GUM Type B assessment (B89.7.4)
* Action by institutions with shared responsibility in use of measurement uncertainty (ASME, ASQ, NCSLI, NIST, NRC-Canada, ...) to
promote use of International Vocabulary of Metrology (VIM (Vendor Independent Messaging Interface) A programming interface developed by Lotus, Novell, IBM and others. In order to enable an application to send and receive mail over a VIM-compliant messaging system such as cc:Mail, programmers write to the VIM interface. )
identify inconsistencies in terminology, vocabulary, and interpretation within their respective domains
identify dimensional-metrology instruments lacking consensus
standards on uncertainty-related performance specifications and testing
inform appropriate standards committees of such inconsistencies in terminology and absence of needed instrument performance tests.
5.7 Establishment of Sound Practice on Technical Qualification of Assessors
Problem: Variability in technical qualifications of laboratory accreditation assessors and/or technical experts resulting in inconsistencies among accredited accredited
recognition by an appropriate authority that the performance of a particular institution has satisfied a prestated set of criteria.
cattle herds which have achieved a low level of reactors to, e.g. laboratories compromises (in some cases) the actual or perceived integrity of the laboratory accreditation process.
Solution: Development and application by NACLA (National Cooperation for Laboratory Accreditation) of sound practice and a uniform method for the specification and verification of the technical qualifications of assessors, whether they be the assessors themselves or the technical experts that operate with formal assessors in the laboratory accreditation process.
5.8 Operational Follow-Up to Recommendations
As an operational follow-up recommendation, the participants in the workshop together recommend the establishment by the organizers of the workshop of an "Ad-Hoc Group on Measurement Uncertainty in Dimensional Measurements" made up of the organizers, volunteers from among the other participants of the workshop, and other interested parties to pursue by appropriate actions the seven other recommendations of the workshop.
The participants of the workshop also suggest:
a prompt follow-up meeting of workshop participants and others
posting of workshop presentations immediately on the NIST/PED website
a publicity article on the workshop by the organizers in appropriate journals such as a Conference Report in the Journal of Research of NIST.
The following workshop participants volunteered or were nominated to take follow-up actions on the various recommendations of the workshop:
(1) establishment of steering group on education in measurement uncertainty, including proposal to NCSL NCSL National Conference of State Legislatures
NCSL National College for School Leadership
NCSL National Conference of Standards Laboratories
NCSL National Council of State Legislators
NCSL National Computer Systems Laboratory (NIST) to take special role in steering group Steve Stahley, Walt Lehmus, Jim Ferguson, Ed Morse
(2) establishment of a consortium on meeting industrial needs Rob McNaughton (to work, not lead)
(3) establishment of a website on documentary information Jay Raja (nominated)
(4) development of business-case justifications on use of uncertainty John Buttress buttress, mass of masonry built against a wall to strengthen it. It is especially necessary when a vault or an arch places a heavy load or thrust on one part of a wall. representing ASME B89.7 committee
(5) development of accreditation-related standard methods (workshop organizers by default)
(6) addressing specific technical issues by a standards committee (workshop organizers by default)
(7) establishment of sound practice on qualification of assessors (workshop organizers by default).
(1.) See Appendix A for explanations of acronyms.
6. Appendix A. Acronyms AMTMA American Measuring Tool Manufacturers Association ASME American Society of Mechanical Engineers ASQ American Society for Quality BIPM Bureau Internationale des Poids et Mesures CCG Calibration Coordinating Group CMM Coordinate Measuring Machine DOD Department of Defense DOE Department of Energy FMEA Failure Mode and Effects Analysis GUM ISO Guide to the Expression of Uncertainty in Measurement HTI Hutchinson Technology Incorporated ISO International Organization for Standardization JCGM BIPM Joint Committee for Guides in Metrology NACLA National Cooperation for Laboratory Accreditation NVLAP National Voluntary Laboratory Accreditation Program NCSL-I National Conference of Standards Laboratories International NIST National Institute of Standards and Technology NMI National Metrology Institute NRC National Research Council of Canada NSF National Science Foundation OMP NIST Office of Microelectronic Programs PED NIST Precision Engineering Division ROI Return on Investment SAE Society of Automotive Engineers SME Society of Manufacturing Engineers UNC-C University of North Carolina--Charlotte VIM International Vocabulary of Basic and General Terms in Metrology.