scholarly journals Uncertainty of measurement and conformity assessment

2021 ◽  
Vol 854 (1) ◽  
pp. 012093
Author(s):  
Silvana Stajkovic ◽  
Dragan Vasilev ◽  
Mirjana Dimitrijevic ◽  
Nedjeljko Karabasil
Keyword(s):  
Decision Making ◽  
Measurement Uncertainty ◽  
Decision Rule ◽  
Decision Rules ◽  
Conformity Assessment ◽  
Test Results ◽  
Uncertainty Of Measurement ◽  
Tolerance Limits ◽  
Measurement Result ◽  
Testing Laboratories

Abstract Knowledge of the measurement uncertainty of test results is fundamentally important for laboratories, their customers and all parties using and interpreting these results. In conformity assessment, a measurement result is used to decide if an item of interest conforms to a specified requirement. Because of measurement uncertainty, there is always the risk of incorrectly deciding whether or not an item conforms to a specified requirement based on the measured value of a property of the item. Conformity assessment can be quite challenging when the entity measured is so close to the tolerance limits of the specification that its uncertainty, however estimated, critically affects decision-making. In such cases, different decision rules can be used to make statements of conformity. The aim of this paper is to provide a survey of methods for the evaluation of measurement uncertainty in testing, as well as to stress the need for appropriate estimation of measurement uncertainty. This paper also aims to assist testing laboratories in understanding the different decision rules used in conformity assessment and level of risk (such as false accept and false reject) associated with the decision rule employed.

scholarly journals Risk calculations for conformity assessment in practice

2019 ◽  
Author(s):  
Alexandre Allard ◽  
Nicolas Fischer ◽  
Ian Smith ◽  
Peter Harris ◽  
Leslie Pendrill
Keyword(s):  
Decision Making ◽  
Measurement Uncertainty ◽  
Decision Rule ◽  
Prior Information ◽  
Conformity Assessment ◽  
Global Risk ◽  
Wrong Decision ◽  
Iso 17025 ◽  
Incorrect Decision ◽  
Testing Laboratories

In 2012, the Joint Committee for Guides in Metrology (JCGM) published novel guidance on the consideration of measurement uncertainty for decision-making in conformity assessment (JCGM 106:2012). The two situations of making a wrong decision are considered: the risk of accepting a non-conforming item, denoted as the customer risk, and the risk of rejecting a conforming item, denoted as the producer risk. In 2017, the revision of ISO 17025 obliged calibration and testing laboratories to “document the decision rule employed, taking into account the level of risk (such as false accept and false reject and statistical assumptions) associated with the decision rule employed, and apply the decision rule” in the context of the decision made about the conformity of an item. However, JCGM 106:2012 can in some cases be perceived as quite difficult to apply for non-statisticians as it mainly relies on calculations involving probability distributions. In order to facilitate uptake of the methodology of JCGM 106:2012, EURAMET is funding the project EMPIR 17SIP05 “CASoft” (2018 – 2020), involving the National Measurement Institutes from France, Sweden and the UK. The objective is to make the methodology accessible to organisations involved in decision-making in conformity assessment: calibration and testing laboratories, industrialists and regulation authorities. Where the customer or producer are concerned, there are two kinds of risks arising from measurement uncertainty: specific risk which concerns the risk of an incorrect decision for a particular item and global risk which is the risk of an incorrect decision for any item chosen at random. Both kinds of risk may involve prior information, taken into account through a so-called prior probability distribution, introducing the concept of a Bayesian evaluation of the risks. If a calibration and testing laboratory performing the measurement has difficulty accessing prior information, it is likely that the industrialist in control of production processes will have some idea of the quality of the items produced. In this paper, the two problems of estimating the specific and global risks are addressed. The consideration of prior information is also discussed through a practical example as well as the use of software implementing the methodology, which will be made publically available at the end of the project.

Decision rules, escalation of commitment and sensitivity to framing in group decision-making

2016 ◽  
Vol 54 (7) ◽  
pp. 1649-1668 ◽  
Author(s):  
Petru Lucian Curseu ◽  
Sandra G. L. Schruijer ◽  
Oana Catalina Fodor
Keyword(s):  
Decision Making ◽  
Decision Rule ◽  
Group Decision Making ◽  
Group Decision ◽  
Decision Rules ◽  
Escalation Of Commitment ◽  
Group Level ◽  
Content Type ◽  
The Impact ◽  
Collaborative Decision

Purpose – The purpose of this paper is to test the influence of collaborative and consultative decision rules on groups’ sensitivity to framing effect (FE) and escalation of commitment (EOC). Design/methodology/approach – In an experimental study (using a sample of 233 professionals with project management experience), the authors test the effects of collaborative and consultative decision rules on groups’ sensitivity to EOC and FE. The authors use four group decision-making tasks to evaluate decision consistency across gain/loss framed decision situations and six decision tasks to evaluate EOC for money as well as time as resources previously invested in the initial decisions. Findings – The results show that the collaborative decision rule increases sensitivity to EOC when financial resources are involved and decreases sensitivity to EOC when time is of essence. Moreover, the authors show that the collaborative decision rule decreases sensitivity to FE in group decision making. Research limitations/implications – The results have important implications for group rationality as an emergent group level competence by extending the insights concerning the impact of decision rules on emergent group level cognitive competencies. Due to the experimental nature of the design, the authors can probe the causal relations between the investigated variables, yet the authors cannot generalize the results to other settings. Practical implications – Managers can use the insights of this study in order to optimize the functioning of decision-making groups and to reduce their sensitivity to FEs and EOC. Originality/value – The study extends the research on group rationality and it is one of the few experimental attempts used to understand the role of decision rules on emergent group level rationality.

Application of Statistical Quality Control in Testing Labs for Estimation of Machine Interference

2019 ◽  
pp. 77-98
Author(s):  
Nitin K. Mandavgade ◽  
Santosh B. Jaju ◽  
Ramesh R. Lakhe
Keyword(s):  
Performance Measures ◽  
System Performance ◽  
Testing Equipment ◽  
Statistical Quality Control ◽  
Test Results ◽  
Uncertainty Of Measurement ◽  
Testing Laboratories ◽  
Machine Interference ◽  
Analysis Of Results

The performance and maintenance of testing laboratories is a prime issue. The quality of coal test results not only depends on performance of individual results but it also depends on the performance of various tests in the same laboratory. Machine interference is a significant problem in many manufacturing system and testing equipment. The variation of results for testing equipment may be due to various factors which need to calculate the uncertainty of measurement to show the accuracy of the machine. In case of coal testing laboratory, the plant layout and surrounding environment affects the performance of the system. The machine interference comes under variable causes which may affect the result. This chapter proposes a methodology for constructing system performance measures, finding out the various factors responsible for variations in result. The chapter deals with estimation of machine interference existence using variable control chart approach for coal testing equipment. The analysis of results for such machine interference will be useful and significant for system designers and practitioners.

scholarly journals Ranking of Weighted Majority Rules

2008 ◽  
Vol 45 (04) ◽  
pp. 994-1006
Author(s):  
Daniel Berend ◽  
Yuri Chernyavsky ◽  
Luba Sapir
Keyword(s):  
Decision Making ◽  
Decision Rule ◽  
Decision Rules ◽  
Collective Decision ◽  
Correct Decision ◽  
Weighted Majority ◽  
The Family ◽  
Effective Decision ◽  
Majority Rules ◽  
Rule Out

A decision-making body may utilize a wide variety of different strategies when required to make a collective decision. In principle, we would like to use the most effective decision rule, that is, the rule yielding the highest probability of making the correct decision. However, in reality we often have to choose a decision rule out of some restricted family of rules. Therefore, it is important to be able to rank various families of rules. In this paper we consider three classes of decision rules: (i) balanced expert rules, (ii) the so-called single expert rules, and (iii) restricted majority rules. For the first two classes, we show that, as we deviate from the best rule in the family, the effectiveness of the decision rule decreases. For the last class, we obtain a very different phenomenon: any inner ranking is possible.

scholarly journals Ranking of Weighted Majority Rules

2008 ◽  
Vol 45 (4) ◽  
pp. 994-1006
Author(s):  
Daniel Berend ◽  
Yuri Chernyavsky ◽  
Luba Sapir
Keyword(s):  
Decision Making ◽  
Decision Rule ◽  
Decision Rules ◽  
Collective Decision ◽  
Correct Decision ◽  
Weighted Majority ◽  
The Family ◽  
Effective Decision ◽  
Majority Rules ◽  
Rule Out

A decision-making body may utilize a wide variety of different strategies when required to make a collective decision. In principle, we would like to use the most effective decision rule, that is, the rule yielding the highest probability of making the correct decision. However, in reality we often have to choose a decision rule out of some restricted family of rules. Therefore, it is important to be able to rank various families of rules. In this paper we consider three classes of decision rules: (i) balanced expert rules, (ii) the so-called single expert rules, and (iii) restricted majority rules. For the first two classes, we show that, as we deviate from the best rule in the family, the effectiveness of the decision rule decreases. For the last class, we obtain a very different phenomenon: any inner ranking is possible.

scholarly journals Proposed approach for force transducers classification

2021 ◽  
Vol 12 ◽  
pp. 3
Author(s):  
Gouda M. Mahmoud ◽  
Seif M. Osman ◽  
Riham S. Hegazy
Keyword(s):  
Decision Making ◽  
Decision Rule ◽  
Classification Criteria ◽  
Uncertainty Of Measurement ◽  
Classification Approach ◽  
Force Transducers ◽  
Relative Errors ◽  
Recent Version

In accordance with the recent version of ISO 376:2011, the classification of the force transducers is based on the relative errors calculated from the calibration results. This classification approach doesn't take the uncertainty of measurement into consideration. It becomes one of the most important factors that must be utilized when making a classification decision based on of ISO/IEC 17025:2017. In this study a proposed approach for force proving instrument classification was developed. This approach is based on taking into account the calibration results uncertainty of the instruments as a decision rule for classifications. Since the expanded budget uncertainty is a combination of different parameters that may affect the classifications decisions so it is more realistic and more accurate for decision making. The results of this paper demonstrate a recommendation for ISO 376:2011 to modify its classification criteria for the force proving instruments in the upcoming version of this standard.

scholarly journals Analysis of measurement uncertainty sources in the casting process

2021 ◽  
Vol 9 (2) ◽  
pp. 1-4
Author(s):  
Lisiane Trevisan ◽  
Vinicius de Freitas Paz ◽  
Daniel Antonio Kapper Fabricio
Keyword(s):  
Decision Making ◽  
Literature Review ◽  
Measurement Uncertainty ◽  
Casting Process ◽  
World Market ◽  
Uncertainty Of Measurement ◽  
Uncertainty Sources ◽  
Uncertainty Calculation ◽  
The World ◽  
Productive Process

The concepts used in metrology are increasingly part of the productive process of metallurgical companies, considering the globalization of the world market. The interpretation of metrological concepts and their application in decision-making is still a challenge for the industry, especially for the measurement uncertainty calculation. Industries in the casting area are in great need of skilled labor both in relation to the productive process and engineering, as well as in metrology, highlighting the interdisciplinary of the concepts studied in the technical or baccalaureate courses. Therefore, the main objective of this work is to perform a brief literature review of publications made using the value of uncertainty of measurement within the production process of foundries. The results show that there is a potential research in the field, to which it relates the values of measurement uncertainty and fused components.

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