Quality control charts based on ranked set sampling under various symmetric distributions

Download
2013
Egemen, Didem
Quality of a product is a very important property for producers and service providers, and can be maintained by statistical quality control methods. One of these methods is Shewhart control chart, which is the most frequently used in the literature. Construction of accurate control limits is the main issue in this method and it strictly depends on the efficiency of the estimators used to construct control limits. In this thesis, a new sampling method ranked set sampling (RSS), which is more efficient than simple random sampling (SRS), is proposed in the estimation part of Shewhart control charts. With this aim, quality control charts constructed by using SRS and RSS are compared under three different symmetric distributions which are normal, long-tailed symmetric and short-tailed symmetric. The simulation results show that RSS provides more efficient estimators compared to SRS. Moreover, it is demonstrated by simulations that type I errors of the charts obtained by RSS technique are very close to the predefined error level. To give a better illustration of the methods, a real life example is provided at the end of the study.

Suggestions

Quality and entry deterrence
Karaer, Özgen (2015-01-01)
We analyze the role of quality, which we define as an attribute of a product that increases consumers' willingness to buy, as a competitive tool in a quality-price setting. We consider an incumbent's entry-deterrence strategies using quality as a deterrent when faced by a potential entrant. We investigate settings motivating the incumbent to blockade the entrant (i.e., prevent entry without extra effort), deter the entrant (i.e., prevent entry with extra effort), or accommodate the entrant (i.e., allow the ...
Comparison of methods for robust parameter design of products and processes with an ordered categorical response
Bacanlı Karabulut, Gonca; Köksal, Gülser; Department of Industrial Engineering (2013)
Robust design of products or processes with categorical response has more momentous role in industrial experiments for quality improvements, because ordinal categorical quality characteristics are encountered more frequent than continuous ones in industry. In this study, five optimization methods for an ordered categorical response are compared with each other: Logistic Regression Model Optimization (LRMO), Accumulation Analysis (AA), Weighted Signal-to-noise Ratio (WSNR), Scoring Scheme (SS), and Weighted ...
Apply Quantitative Management Now
TARHAN, AYÇA; Demirörs, Onur (Institute of Electrical and Electronics Engineers (IEEE), 2012-05-01)
The Assessment Approach for Quantitative Process Management (A2QPM) helps identify software process measures for quantitative analysis even when organizations lack formal systems for process measurement. A2QPM is the first approach to quantitative management that offers software organizations a well-defined, detailed guideline for assessing their software processes and applying beneficial quantitative techniques to improve them. All the A2QPM applications we've described resulted in quantitative analysis im...
Unified Process Modeling with UPROM Tool
Aysolmaz, Banu; Demirörs, Onur (2014-06-20)
UPROM tool is a business process modeling tool designed to conduct business process and user requirements analysis in an integrated way to constitute a basis for process automation. Usually, business process models are not utilized systematically to develop related artifacts, specifically when a process-aware information system is to be developed to automate those processes. This results in completeness, consistency and maintainability problems for those artifacts. Unified business process modeling methodol...
Forecasting of Product Quality Through Anomaly Detection
Dinç, Mehmet; Ertekin Bolelli, Şeyda; Özkan, Hadi; Meydanlı, Can; Atalay, Mehmet Volkan (2020)
Forecasting of product quality by means of anomaly detection is crucial in real-world applications such as manufacturing systems. In manufacturing systems, the quality is assured through tests performed on sample units randomly chosen from a batch of manufactured units. One of the major issues is to detect defective units among the sample test units as early as possible in terms of test time and of course as accurate as possible. Traditional way of detecting defective units is to make use of human experts d...
Citation Formats
D. Egemen, “Quality control charts based on ranked set sampling under various symmetric distributions,” M.S. - Master of Science, Middle East Technical University, 2013.