Monitoring reliability for a three-parameter Weibull distribution

2009-02-01
Control charts are widely used to monitor production processes in the manufacturing industry and are also useful for monitoring reliability. A method to monitor reliability has recently been proposed when the distributions of inter-failure times are exponential and Weibull with known parameters. This method has also been extended to monitor the cumulative time elapsed between a fixed number of failures for the exponential distribution. In this paper, we consider a three-parameter Weibull distribution to model inter-failure times, use a robust estimation technique to estimate the unknown parameters, and extend the proposed method to monitor the cumulative time elapsed between r failures using the three-parameter Weibull distribution. Since the distribution of the sum of independent Weibull random variates is not known (except in specific cases with known parameters), we give two useful moment approximations to be able to apply their scheme. We show how effective the approximations are and the usefulness of the method in detecting a possible instability during production.
RELIABILITY ENGINEERING & SYSTEM SAFETY

Suggestions

Guidelines for automating Phase I of control charts by considering effects on Phase-II performance of individuals control chart
Atalay, Murat; TESTİK, MURAT CANER; Duran, Serhan; Weiss, Christian H. (Informa UK Limited, 2019-09-11)
With the advances in measurement technologies, today products and processes may have hundreds of variables that can be monitored. As the number of variables to be monitored in a process increases, a cumbersome task is the design of control charts, especially when one needs to estimate unknown process parameters. In Phase-I control chart implementations, a set of samples that are ideally from an in-control process is formed by iteratively eliminating/retaining potentially out-of-control samples and this is t...
Effective use of quality function deployment and Kansei engineering for product planning with sensory customer requirements: A plain yogurt case
Dolgun, Leman Esra; Köksal, Gülser (Informa UK Limited, 2018-01-01)
Product planning, as typically the first phase of quality function deployment, involves identifying customer requirements and translating them into technical requirements. Understanding true customer needs and setting targets for customer and technical requirements can be very difficult especially when sensory product characteristics such as taste, odor, and texture are concerned. In this study, effective approaches are developed and implemented for overcoming these difficulties in a plain yogurt case. A cu...
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...
Nonconvex optimization of desirability functions
Akteke-Ozturk, Basak; Köksal, Gülser; Weber, Gerhard Wilhelm (Informa UK Limited, 2018-01-01)
Desirability functions (DFs) are commonly used in optimization of design parameters with multiple quality characteristic to obtain a good compromise among predicted response models obtained from experimental designs. Besides discussing multi-objective approaches for optimization of DFs, we present a brief review of literature about most commonly used Derringer and Suich type of DFs and others as well as their capabilities and limitations. Optimization of DFs of Derringer and Suich is a challenging problem. ...
Controlling high quality manufacturing processes: a robustness study of the lower-sided tbe ewma procedure
Pehlivan, Canan; Köksal, Gülser; Department of Industrial Engineering (2008)
In quality control applications, Time-Between-Events (TBE) type observations may be monitored by using Exponentially Weighted Moving Average (EWMA) control charts. A widely accepted model for the TBE processes is the exponential distribution, and hence TBE EWMA charts are designed under this assumption. Nevertheless, practical applications do not always conform to the theory and it is common that the observations do not fit the exponential model. Therefore, control charts that are robust to departures from ...
Citation Formats
B. Sürücü, “Monitoring reliability for a three-parameter Weibull distribution,” RELIABILITY ENGINEERING & SYSTEM SAFETY, pp. 503–508, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46223.