ISSN:0748-8017    

DOI:10.1002/qre.4680050102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0748-8017    

DOI:10.1002/qre.4680050103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractA Taguchi example is used in this note to look at statistical significance under assumptions that may not hold true in a given experiment. I also make a case for including physical reasoning in the experimental process as a way to help in making close calls and to help avoid pitfalls.

ISSN:0748-8017    

DOI:10.1002/qre.4680050104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper reports on the findings of a questionnaire survey into the use of statistical process control (SPC) in a sample of United Kingdom automotive suppliers. All the 76 respondents had attended the Ford‐approved three‐day course on SPC held at the University of Manchester Institute of Science and Technology (UMIST). The survey investigated the following broad issues of SPC: motivation, implementation, application, suppliers and customers, and benefits. A number of findings surprised the authors; these included the number of organizations who had not appointed a SPC facilitator, organizations experiencing difficulties in deciding what type of control charts to use, control charts being ‘filled‐in’ by people not directly responsible for control of a process, charts being displayed away from work areas and the frankness of some suppliers in declaring that the vast majority of their manufacturing processes are not in a state of statistical control. If there is an overall message arising from the findings it is that the introduction and application of SPC should not be overco

ISSN:0748-8017    

DOI:10.1002/qre.4680050105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractDuring initial production of a new product prior to actual production, the decrease in the fraction defective of units produced can be observed as personnel gather experience and the faults in the product's design, manufacturing, etc. are removed. This paper discusses an initial production process control based on a quality growth model proposed here. The model describes a continuing reduction in the cumulative defect rate defined by the ratio of the cumulative number of defective units to that of produced units. A stopping rule is also investigated for determining when to discontinue the initial control of the production process and proceed to the actual production stage. Further, a numerical example of the application is presented.

ISSN:0748-8017    

DOI:10.1002/qre.4680050106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractIt has now become possible to design electronic products that have only a small probability of failing in a period of technologically useful life, if these products are to be used in an environment controlled for human comfort. Such product designs, even ones containing considerable complexity, can use combinations of ASIC and semi‐custom VLSI devices, damage‐resistant packaging and fault‐tolerant techniques to achieve breakthrough reliability. The theme of this paper is that once field failures can be reduced to small fractions of the units produced, by means of such design approaches, then major changes and their accompanying cost savings become possible in the manufacture and support of these electronic products. Although some extra design validation steps will be needed, the resulting opportunities can be very significant for companies that design and manufacture electronic products. This reliability‐enabled strategy is fully described in thi

ISSN:0748-8017    

DOI:10.1002/qre.4680050107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThis is the second part of a three‐part article under the general heading of ‘Off the bathtub onto the roller‐coaster curve’, a short version1of which was presented at the 1988 Annual Reliability and Maintainability Symposium in the U.S.A. The first part was entitled ‘The bathtub does not hold water any more’,2and the last part, to be published in a later issue of this journal, is entitled ‘Physical basis for the roller‐coaster hazard rate curve’. This three‐part article provides detailed discussions of the findings leading to the conclusions on the roller‐coaster characteristics for the hazard rate curve for electronics. Part 1 discussed problems with the bathtub curve. This part explores the shape of the failure rate curve in view of some recent observations. For more than twenty years investigators studying semiconducting device burn‐in have subscribed to the concept of freak failures, which manifest themselves as a hump on the hazard rate curve. In addition to semiconducting device data several sets of screening data, as well as operational data dating all the way back to 1961, also showed that indeed one can expect electronic systems to have generally decreasing failure rate curves with failure humps on them. The author of this paper calls these curves th

ISSN:0748-8017    

DOI:10.1002/qre.4680050108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractA review of the reliability status of GaAs discrete devices and integrated circuits is given. In the present survey of new devices and circuits it is shown that a significant number of reliability problems continue to persist.

ISSN:0748-8017    

DOI:10.1002/qre.4680050109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractDependability has been recognized in the transportation reliability literature as an effective measure of transit system service quality. Dependability models link system dependability with reliability and maintainability characteristics of subsystems, incorporating special operating characteristics and recovery policy from failure of each particular transit system. In this paper a new transit system dependability model is proposed, which considers the possibility that a passenger may be delayed by the occurrence of more than one failure in a trip. The mathematical difficulties associated with the algebra of random variables are overcome by using the Monte Carlo method. The results of the proposed model are compared with those relative to different modelling approaches in the literature, by applying the model to a common test scenario.

ISSN:0748-8017    

DOI:10.1002/qre.4680050110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractFamilies of plastic‐encapsulated logic circuits have been subjected to a qualification procedure. The aim was to qualify them for use in telecommunication equipment in a central office environment. The qualification was based on a large number of reliability tests performed by the Ericsson failure analysis laboratory and by the vendors themselves. Reliability monitoring data from the testing of more than 150,000 devices during the period 1984 to 1985 have been analysed. Life tests, such as ‘high temperature operating life’, ‘high humidity operating life’, and temperature cycling have been performed. A comparison between life‐test data and field data from telephone exchanges in service has also been made. An average activation energy of 0.5 eV has been shown to be useful in such a comparison for the best LS vendors and 0.3 eV for the best HC

ISSN:0748-8017    

DOI:10.1002/qre.4680050111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY