Incorporating risk analysis into life cycle costing

Incorporating risk analysis into life cycle costing

World Abstracts on Microelectronics and Reliability accompanied by high quality and high reliability of electronic equipments, quality requirements fo...

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World Abstracts on Microelectronics and Reliability accompanied by high quality and high reliability of electronic equipments, quality requirements for batteries are becoming increasingly stringent. An Li battery using metallic Lithium as the cathode material is mostly used for memorybackup of electronic equipments and for main power supply and, therefore, requirements for higher reliability and more condensed high-energy are intensified. The Meter and Instrument Department of Yanagicho Works manufactures watt-hour meters as well as electronic power appliances TOSCAM Series, T O S D E M A C Series and automatic meter reading systems. Recently, load survey systems and electronic or static watt-hour meters were added to its manufactures list. Despite severe service environments and long durable service time of Li batteries, the evaluation has been left to the battery makers. Here, a report regarding the reliability of Li batteries from the standpoint of users was summarized by experiments with objectives as follows: (1) study on compatability of Li battery; (2) calculation of field failure rate; (3) confirmation method for long-term guarantee (5 years, 10 years).

Analysis on a cause of rare contact failure in sealed contacts. HIDEO OKAMOTO, HARUO NITTA and SHIGEKI KIKUI. Proc. 16th Symp. Reliab. Maintainab. Japan, 64 (1986). A cause of rare contact failure in sealed contacts was investigated on reed switches. The contact failure implies abnormal high

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Maintability technology. PAUL H. ZORGER. Proc. a. Reliab. Maintainab. Syrup., 77 (1986). This paper presents a brief background and the current application status of maintainability technology. It discusses, from a practical point-ofview the application of this technology to large systems, emphasizing some of the problems associated with the technology when applied to a space environment. Three deficiencies in the technology are discussed: (1) the addition of a maintainability program task on testability to determine the "time" to detect, locate, and isolate faults/failures; (2) "time" data sources--their application and use, and a methodology to synthesize "time" values; (3) the conversion of "time" values for use in a space environment. The paper is structured around a total and complete proposed maintainability program. Some additional and new tasks are suggested as needed additions to MIL-STD-470A and all tasks are defined for a complete and comprehensive maintainability program. This paper discusses the characteristics of a maintainability program and its implementation and application from the point of view of the design engineer. It is based upon the premise that maintainability is a characteristic of a desion and is achieved through incorporation of maintainability design criteria through the design engineering process. The theme of the paper suggests "design for maintainability" and that the characteristic is achieved through "maintainability by design". A multi-step stress-strength model of a parallel system. DAN S. NECSULESCU and ALEXANDER S. KRAUSZ. IEEE Trans. Reliab. R-35(1), 119 (1986). The paper evaluates the reliability of a shared-load parallel system. Each component is subject to a load that depends on the number of currently failed elements. For a finite number of load applications to the system a discrete-time Markov model was developed. Numerical examples are given for the reliability dynamics of a system whose components equally share the load. The accuracy of the results is evaluated for a limited number of non-zero diagonals calculated for the transition matrix.

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contact resistance observed on some of the contacts left opened for fairly long period in natural or in controlled circumstances under electrical standby conditions as in the case of an electronic alarm system.

Reliability of compact disc. YOSHIHARAUCHIHARA, MASHIRO HIGUCHI, YASUSHI MIYOSHI, TOSHIH1RO ROKUJO and SADAO SAKAMOTO. Proc. 16th Syrup. Reliab. Maintainab. Japan, 74 (1986). Compact Disc systems have been generating rapid sales growth since they were commercialized in 1982. Because the Compact Disc (CD) has no direct contact with the signal pickup mechanism of the player, no degradation occurs from disc wear, which is expected to make for almost everlasting life and easier handling of the disc. Compact Discs are being made now for 3 years. The specified figures about the behaviour at end of life can therefore not be derived from real time experiences. These figures are based on accelerated ageing test. Environmental stability, however, has been one of main factors to be successful implementation of Compact Disc. Ordinary CD is susceptible to deformation under extreme high temperature such as in vehicles, and aluminum corrosion by high humidity. Analysis for severe tempera!ure and humidity environments shows that sufficient lifetimes for the storage CD are expected under usual operating environments.

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Bayesian reliability demonstration was one of several new techniques used in the VORTAC program to reduce reliability demonstration test time. The results of using the Bayesian test plan and the results of the reliability demonstration are described.

Incorporating risk analysis into life cycle costing. A. M. FEILER. Proc. a. Reliab. Maintainab. Syrup., 469 (1986). A basic shortcoming of conventional methods of estimating LCC is that they are largely deterministic; that is, they do not account for the impact on LCC of the many project uncertainties which may affect project and system performance at the different stages of the life cycle. The consequence of applying deterministic estimating techniques to cost elements that are probabilistic is to produce estimates that have been generally shown to be inherently optimistic. R&M applications of cost-benefit analysis. RALPH E. KUEHN. Proc. a. Reliab. Maintainab. Syrup., 486 (1986). Examples of R&M cost-benefit analysis from several varied industries are presented. The first example involves changes in the working environment of the maintenance man in a service industry. The efficiency of the maintenance man stated in terms of MTR and useful man-hours is related to the dollar cost of modifying the environment. An example from the entertainment industry involves maintenance of display terminals. The effect of preventive maintenance on perceived MTBF and maintenance man-hours are related to cost. An example from the recreation industry considers maintenance man travel hour reduction by means of linear program scheduling. Maintenance savings are compared to programming costs. A final example from the aerospace industry treats the selection of an alloy for printed circuit board back plates in a space application and the means of attachment to a heat sink. The variables related by cost-benefit analysis are temperature, solid state failure rates, weight, and cost. These cases consider the importance of engineering judgement, non-technical factors, people problems, and political factors.

Integrated D P tools for R&M math and product handling. New techniques in R&M contract requirements. DAVID A. HEISER. Proc. a. Reliab. Maintainab. Syrup., 480 (1986). A MR 27: 4-M

K JELL STRANDBERGand STAFFANBERGSTEN. Proc. a. Reliab. Maintainab. Syrup., 20 (1986). Data processing tools are often