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Thesis (M.S.)--State University of New York at Binghamton, Industrial and Systems Engineering Department, 2006. / Includes bibliographical references.

Project report (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Abstract. Includes bibliographical references (leaves 72-75). Also available via the Internet.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains ix, 130 p. : ill. Includes abstract.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 313-327). Also available in electronic version.

An attempt is made in this thesis to study some stochastic models of both reliability and inventory systems with reference to the following aspects: (i) the confidence limits with the introduction of common-cause failures. (ii) the Erlangian repair time distributions. (iii) the product interactions and demand interactions. (iv) the products are perishable. This thesis contains six chapters. Chaper 1 is introductory in nature and gives a review of the literature and the techniques used in the analysis of reliability systems. Chapter 2 is a study of component common-cause failure systems. Such failures may greatly reduce the reliability indices. Two models of such systems (series and parallel) have been studied in this chapter. The expressions such as, reliability, availability and expected number of repairs have been obtained. The confidence limits for the steady state availability of these two systems have also been obtained. A numerical example illustrates the results. A 100 (1 - a) % confidence limit for the steady state availability of a two unit hot and warm standby system has been studied, when the failure of an online unit is constant and the repair time of a failed unit is Erlangian. The general introduction of various inventory systems and the techniques used in the analysis of such systems have been explained in chapter 4. Chapter 5 provides two models of two component continuous review inventory systems. Here we assume that demand occurs according to a poisson process and that a demand can be satisfied only if both the components are available in inventory. Back-orders are not permitted. The two components are bought from outside suppliers and are replenished according to (s, S) policy. In model 1 we assume that the lead-time of the components follow an exponential distribution. By identifying the inventory level as a Markov process, a system of difference-differential equations at any time and the steady-state for the state of inventory level are obtained. Tn model 2 we assume that the lead-time distribution of one product is arbitrary and the other is exponential. Identifying the underlying process as a semi-regenerative process we find the stationary distribution of the inventory level. For both these models, we find out the performance measures such as the mean stationary rate of the number of lost demands, the demands satisfied and the reorders made. Numerical examples for the two models are also considered. Chaper 6 is devoted to the study of a two perishable product inventory model in which the products are substitutable. The perishable rates of product 1 and product 2 are two different constants. Demand for product 1 and product 2 follow two independent Poisson processes. For replenishment of product 1 (s, S) ordering policy is followed and the associated lead-time is arbitrary. Replenishment of product 2 is instantaneous. A demand for product 1 which occurs during its stock-out period can be substituted by product 2 with some probability. Expressions are derived for the stationary distribution of the inventor}' level by identifying the underlying stochastic process as a semi-regenerative process. An expression for the expected profit rate is obtained. A numerical illustration is provided and an optimal reordering level maximising the profit rate is also studied. To sum up, this thesis is an effort to improve the state the of art of (i) complex reliability systems and their estimation study (ii) muitiproduct inventory systems. The salient features of the thesis are: (i) Analysis of a two-component reliability system with common-cause failures. (ii) Estimation study of a complex system in which the repair time for both hot standby and warm standby systems are assumed to be Eriangian. (iii) A multi-product continuous review inventory system with product interaction, with a (s, S) policy. (iv) Introduction of the concept of substitutability for products. (v) Derivation of expressions for various statistical measures. (vi) Effective use of the regeneration point technique in deriving various measures for both reliability and inventory systems. (vii) Illustration of the various results by extensive numerical work. (vii) Consideration of relevant optimization problems. / Mathematical Sciences / PhD (Statistics)

M. Ing. / The design of electric motor systems as we know it today, is very important and has a direct influence on the reliability of the system. In this dissertation, recommendations in design are given to obtain a reliable electric motor system. This dissertation covers a literature review of reliability engineering, and this is then applied to an electric motor system in order to determine the reliability of the system. This dissertation is divided into five parts: Problem definition, theory and literature survey, economics of reliability engineering, analysis and synthesis of an electrical motor system, conclusions and recommendations. Part I describes the environment of an electric motor system and presents some fundamental concepts of reliability engineering. It emphasizes the importance of reliability analysis in the design of electric motor systems. Part II describes some theory and literature about reliability. It emphasizes some existing reliability analysis methods for development of electric motor systems. The reliability prediction method is very useful for analysis of electric motor systems. The author emphasizes that economics of reliability engineering should be taken into account in the design process in Part III. The analysis of life cycle costs is very important. Life cycle costs (LCC) usually consist of the initial investment, preventive maintenance costs, repair costs and the costs for production losses and outages due to failures and disturbances. Life cycle costing methodology is useful in analyzing the design, reliability and maintenance during trade off of technical systems and equipments. Part IV focuses a specific electric motor system. Some existing reliability analysis methods are used to analyse reliability of electric motor systems. It is highlighted how to improve the reliability of electric motor systems. Some economics considerations are also presented in this section. The main conclusion reached in this dissertation is that failure data feedback, and accurate records are very important for reliability engineering. The author makes some recommendations for reliability of an electric motor system in design. This dissertation may contain direct information from sources indicated generally by. This is however generally contextualized within the main aim of the research. This is the result of specific communication obstacles.