scholarly journals The prospect of using Shewhart control charts in assessing the quality of ionometric measurements by the method of adding a sample to a standard

2021 ◽  
Vol 21 (4) ◽  
pp. 399-404
Author(s):  
Vladislav M. Shatunov ◽  
◽  
Anna I. Fokina ◽  
Tamara Ya. Ashikhmina ◽  
◽  
...  
Keyword(s):  
Quality Control ◽  
Control Charts ◽  
Control Procedure ◽  
Angular Coefficient ◽  
Addition Method ◽  
Electrode Function ◽  
Shewhart Control ◽  
Accuracy Of Measurements ◽  
Measurement Results

Modern methods of quantitative physical and chemical measurements should necessarily include procedures for quality control of research results. Recently, the procedure for quality control of measurements using control charts is gaining particular popularity in the practice of analytical measurements. To date, the methods of potentiometric studies operating in the territory of the Russian Federation, in most cases, do not include quality control using this control procedure. However, despite the complexity of the implementation and interpretation of its results, it is the use of control charts that allows you to control the quality of ionometric measurements. This is especially important for potentiometric determinations based on the addition method, since the instability of the slope of the electrode function and its deviation significantly contribute to the uncertainty of the measurement results. This article presents the main results of evaluating the use of the Shewhart control chart method for monitoring the repeatability and accuracy of measurement results. The measurement results have been obtained using an improved method of quantitative potentiometric determination of high concentrations (more than 1 gm/cdm) of ammonium ions by the method of adding a sample to the standard. In addition, an experimental substantiation of the fact that the value of the slope of the electrode function significantly affects the accuracy of measurements by the addition method has been presented. It has been revealed that when the angular coefficient of the electrode function is more than 62 mV/pNH4+ at (25±5)°C, deviations of the measurement results from the control standard by more than 50% are observed. It has been found that at (25±5)°С the most accurate results of quantitative determination are achieved when the angular coefficient of the electrode function is from 54 mV/pNH4+ to 62 mV/pNH4+ inclusive.

scholarly journals A Fuzzy Control Chart Approach for Attributes and Variables

2018 ◽  
Vol 8 (5) ◽  
pp. 3360-3365 ◽  
Author(s):  
N. Pekin Alakoc ◽  
A. Apaydin
Keyword(s):  
Quality Control ◽  
Fuzzy Control ◽  
Control Chart ◽  
Control Charts ◽  
Fuzzy Numbers ◽  
Fuzzy Theory ◽  
New Approach ◽  
Shewhart Control Charts ◽  
Shewhart Control ◽  
Quality Control Chart

The purpose of this study is to present a new approach for fuzzy control charts. The procedure is based on the fundamentals of Shewhart control charts and the fuzzy theory. The proposed approach is developed in such a way that the approach can be applied in a wide variety of processes. The main characteristics of the proposed approach are: The type of the fuzzy control charts are not restricted for variables or attributes, and the approach can be easily modified for different processes and types of fuzzy numbers with the evaluation or judgment of decision maker(s). With the aim of presenting the approach procedure in details, the approach is designed for fuzzy c quality control chart and an example of the chart is explained. Moreover, the performance of the fuzzy c chart is investigated and compared with the Shewhart c chart. The results of simulations show that the proposed approach has better performance and can detect the process shifts efficiently.

Improving Benchmarking Student Learning Outcomes Using Repetitive Sampling Control Chart

2016 ◽  
Vol 13 (10) ◽  
pp. 7036-7039
Author(s):  
Nawal G Alghamdi ◽  
Muhammad Aslam
Keyword(s):  
Control Chart ◽  
Control Charts ◽  
Assessment Tool ◽  
Educational Programs ◽  
Management Program ◽  
Pass Rate ◽  
Shewhart Control Charts ◽  
Process Understanding ◽  
Shewhart Control

In recent years research on the application of Shewhart control charts in evaluating the performance of educational programs have gain sufficient grounds. These control charts aid in process understanding and identify changes that indicate either improvement or deterioration in quality of the program. Current research proposes control charts using repetitive sampling on the data taken from Weber State University’s construction management program, which uses the Associate Constructor Level 1 exam as an assessment tool. A code was developed to run the proposed control charts. Both the traditional and proposed charts were plotted using R software. The results indicate that the proposed control charts are comparatively more efficient than the traditional control charts in assessment of educational programs and minimizing false positives. At the end comparison of the benchmark—pass rate and traditional control chart with the proposed control chart has also been elucidated so that the proposed control charts may be readily employed in evaluating any educational program by academic counsellors.

scholarly journals Estimation of Consistency of Production of the Pertussis Component of DTP Vaccine in Terms of Immunogenic Activity and Specific Safety Using Shewhart Charts

2018 ◽  
Vol 18 (4) ◽  
pp. 243-248
Author(s):  
I. A. Alekseeva ◽  
O. V. Perelygina ◽  
E. D. Kolyshkina
Keyword(s):  
Quality Control ◽  
Technological Process ◽  
Control Charts ◽  
Whooping Cough ◽  
Primary Vaccination ◽  
Statistical Control ◽  
Shewhart Control ◽  
Dtp Vaccine ◽  
Time Basis ◽  
Shewhart Charts

WHO experts attribute the resurgence of whooping cough to the wide use of acellular pertussis vaccines (aPs) as components of combination products. In this regard, WHO encourages countries that have not yet switched to the use of aPs to continue to use whole-cell pertussis vaccines (wPs) for primary vaccination. The experience of using pertussis vaccines has shown that companies do not always produce highly efficacious products. The use of statistical methods of samples quality control helps to ensure consistency of the technological process, which results in the production of more homogeneous products, and rules out the possibility of producing low-quality products. This paper presents the results of retrospective evaluation of the consistency of the wP (as a pertussis component of the DTP vaccine) production using Shewhart control charts. It was shown that at some points in time during the analyzed period from January 2017 until March 2018 the technological process of the company lacked proper statistical control. This increased the risk of producing non-uniform and defective products. In order to improve the quality and consistency of pertussis component batches, the company’s quality control and quality assurance services should make extensive use of Shewhart charts on a real-time basis.

scholarly journals Application of Shewhart's control card to supervise the quality of manufacturing process in the automotive industry

2018 ◽  
Vol 19 (9) ◽  
pp. 108-111
Author(s):  
Emilia Bachtiak-Radka ◽  
Sara Dudzińska ◽  
Daniel Grochała
Keyword(s):  
Automotive Industry ◽  
Control Charts ◽  
Individual Characteristic ◽  
Control Card ◽  
Automated Production ◽  
Shewhart Control Charts ◽  
Shewhart Control ◽  
Geometrical Features ◽  
Shape Characteristics

The manuscript presents the use of Shewhart control charts to supervision the quality of production processes in the automotive industry of the gearbox automatic. At the request of the company, control charts were prepared for individual characteristic geometrical features. This paper presents the procedure for preparing the control card for monitoring the shape characteristics in an automated production socket.

scholarly journals COLLABORATIVE TRIAL AND QUALITY CONTROL IN CHEMICAL ANALYSIS

2010 ◽  
Vol 2 (3) ◽  
pp. 135-141
Author(s):  
Narsito Narsito
Keyword(s):  
Quality Control ◽  
Chemical Analysis ◽  
Analytical Method ◽  
Control Charts ◽  
Analytical Data ◽  
Control Program ◽  
Quality Parameter ◽  
Quality Control Program ◽  
And Control

Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data

scholarly journals Loading time monitoring via individual control charts

2019 ◽  
Vol 7 (10) ◽  
pp. 331-338
Author(s):  
MARIA EMILIA CAMARGO ◽  
Walter Priesnitz Filho ◽  
Suzana Leitão Russo ◽  
Angela Isabel Dos Santos Dullius ◽  
Ademar Galelli ◽  
...  
Keyword(s):  
Quality Control ◽  
Control Charts ◽  
Rio Grande ◽  
Quality Characteristics ◽  
Quality Of Services ◽  
Rio Grande Do Sul ◽  
Individual Control ◽  
Cargo Transport ◽  
The Individual

In quality control we find techniques that come from different fields, because the objective is to reduce the variability in quality characteristics, these are control and adjustment of processes. In this work, the individual control charts (Xind and Rm) were used to monitor the loading time of a truck measured during 60 consecutive days of a cargo transport company in Rio Grande do Sul. The results showed that the process is out of control both in average and variability, requiring a systematic monitoring in order for the company to maintain the quality of services provided to its customers.

Application of Statistical Process Control Tools to Improve Product Quality in Manufacturing Processes

2011 ◽  
Vol 110-116 ◽  
pp. 4023-4027
Author(s):  
Omar Bataineh ◽  
Abdullah Al-Dwairi
Keyword(s):  
Quality Control ◽  
Process Control ◽  
Statistical Process Control ◽  
Control Charts ◽  
Process Capability ◽  
Manufacturing Processes ◽  
Statistical Process ◽  
Free Products ◽  
Drug Companies

Quality control and improvement at the process level is a vital activity for the achievement of defect-free products in various manufacturing processes. This study employs statistical process control (SPC) tools such as control charts and process capability ratio for quality control and improvement. The control charts employed are , R and the cumulative-sum (CUSUM). The process capability ratio used is the so called process capability index (PCI). These tools have been implemented with the aid of Minitab® statistical software. In this study, the manufacturing process of gelatin capsules is investigated in terms of quality of the capsules, which are produced and shipped for use by various drug companies. As a result of implementation of SPC tools, an expected reduction in the number of defective capsules by 29% relative to the stage before implementation was achieved.

scholarly journals Tabular cusum control charts of chemical variables applied to the control of surface water quality

2012 ◽  
Vol 32 (5) ◽  
pp. 951-960 ◽  
Author(s):  
Franciele A. C. Follador ◽  
Márcio A. Vilas Boas ◽  
Marlise Schoenhals ◽  
Eliane Hermes ◽  
Clovis Rech
Keyword(s):  
Water Quality ◽  
Quality Control ◽  
Surface Water ◽  
Water Samples ◽  
Control Charts ◽  
Field Research ◽  
Surface Water Quality ◽  
Small Samples ◽  
Cusum Control Charts

The aim of this study was to evaluate the application possibility of tabular CUSUM control charts in the quality control of chemical variables in surface water. It was performed bibliographic and field research to collect water samples from 2003 to 2009, totaling 30 samples, some monthly and others semi-annual in order to observe the variables that regulate water quality. It was found that these charts may be applied to control the quality of river water; showing to be effective in the perception of changes during the process, especially for small samples (n=1) which there is no repetition as in this research. It was also concluded that the Mandurim River does not presents significant levels of pollution.

scholarly journals Uniformity microsprinkler irrigation system using statistical quality control

2017 ◽  
Vol 47 (4) ◽  
Author(s):  
Maurício Guy de Andrade ◽  
Marcio Antonio Vilas Boas ◽  
Jair Antonio Cruz Siqueira ◽  
Mireille Sato ◽  
Jonathan Dieter ◽  
...  
Keyword(s):  
Quality Control ◽  
Control Charts ◽  
Irrigation System ◽  
Process Capability ◽  
Process Capability Index ◽  
Statistical Quality Control ◽  
Uniformity Coefficient ◽  
Statistical Quality ◽  
Capability Index ◽  
Shewhart Control

ABSTRACT: The objective of this study was to evaluate the use of statistical quality control tools in the analysis of the uniformity of a microsprinkler irrigation system. For the analysis of irrigation Christiansen uniformity coefficient (CUC) and the distribution uniformity coefficient (DU) were statistically analyzed by means of the Shewhart control charts and process capability index (Cp). For the experiment 25 tests were carried out with a single micro sprinkler and subsequently seven different spacing between micro sprinklers were simulated. Control charts contributed to the diagnosis of the treatments to be under control and with satisfactory uniformity outcomes. Increase in process capability index was directly proportional to the average of CUC and DU.

scholarly journals Correction of Biogeochemical-Argo Radiometry for Sensor Temperature-Dependence and Drift: Protocols for a Delayed-Mode Quality Control

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6217
Author(s):  
Quentin Jutard ◽  
Emanuele Organelli ◽  
Nathan Briggs ◽  
Xiaogang Xing ◽  
Catherine Schmechtig ◽  
...  
Keyword(s):  
Quality Control ◽  
Light Field ◽  
Control Procedure ◽  
Ocean Optics ◽  
Night Time ◽  
Underwater Light Field ◽  
Time Profiles ◽  
Accuracy Of Measurements ◽  
Sensor Temperature ◽  
Radiometric Data

Measuring the underwater light field is a key mission of the international Biogeochemical-Argo program. Since 2012, 0–250 dbar profiles of downwelling irradiance at 380, 412 and 490 nm besides photosynthetically available radiation (PAR) have been acquired across the globe every 1 to 10 days. The resulting unprecedented amount of radiometric data has been previously quality-controlled for real-time distribution and ocean optics applications, yet some issues affecting the accuracy of measurements at depth have been identified such as changes in sensor dark responsiveness to ambient temperature, with time and according to the material used to build the instrument components. Here, we propose a quality-control procedure to solve these sensor issues to make Argo radiometry data available for delayed-mode distribution, with associated error estimation. The presented protocol requires the acquisition of ancillary radiometric measurements at the 1000 dbar parking depth and night-time profiles. A test on >10000 profiles from across the world revealed a quality-control success rate >90% for each band. The procedure shows similar performance in re-qualifying low radiometry values across diverse oceanic regions. We finally recommend, for future deployments, acquiring daily 1000 dbar measurements and one night profile per year, preferably during moonless nights and when the temperature range between the surface and 1000 dbar is the largest.

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