An estimate of maintenance efficiency in Brown-Proschan imperfect repair model with bathtub failure intensity

Purpose: Estimate the maintenance efficiency in the Brown-Proschan model with the bathtub failure intensity. Design/methodology/approach: Empirical research through which we propose a framework to establish the characteristics of failure process and its influence on maintenance process. Findings: The main contribution of the present study is the reformulation of the Brown and Proschan model using the bathtub failure intensity Practical implications: Our model is defined by BP reformulation one using bathtub failure intensity. This form of intensity is presented like superposition of two NHPP and Homogeneous Poisson one. Originality/value: This is the follow on research on the study that employed the power-law-process type of failure intensity.Peer Reviewe

An estimate of maintenance efficiency in Brown-Proschan imperfect repair model with bathtub failure intensity

Purpose: Estimate the maintenance efficiency in the Brown-Proschan model with the bathtub failure intensity. Design/methodology/approach: Empirical research through which we propose a framework to establish the characteristics of failure process and its influence on maintenance process. Findings: The main contribution of the present study is the reformulation of the Brown and Proschan model using the bathtub failure intensity Practical implications: Our model is defined by BP reformulation one using bathtub failure intensity. This form of intensity is presented like superposition of two NHPP and Homogeneous Poisson one. Originality/value: This is the follow on research on the study that employed the power-law-process type of failure intensity

An estimate of maintenance efficiency in Brown-Proschan imperfect repair model with bathtub failure intensity

Purpose: Estimate the maintenance efficiency in the Brown-Proschan model with the bathtub failure intensity. Design/methodology/approach: Empirical research through which we propose a framework to establish the characteristics of failure process and its influence on maintenance process. Findings: The main contribution of the present study is the reformulation of the Brown and Proschan model using the bathtub failure intensity Practical implications: Our model is defined by BP reformulation one using bathtub failure intensity. This form of intensity is presented like superposition of two NHPP and Homogeneous Poisson one. Originality/value: This is the follow on research on the study that employed the power-law-process type of failure intensity.Peer Reviewe

A TOPSIS method based on intuitionistic fuzzy values: a case study of North African airports

In this paper we develop a fuzzy TOPSIS method based on intuitionistic fuzzy values to solve multiple criteria decision making problems in which the performance rating of alternatives values and the weights of criteria are given by linguistic terms. Arithmetic operations between intuition-istic fuzzy values are used for normalizing imprecise ratings and weights of criteria. In order to demonstrate the effectiveness of the suggested method, we propose a case study aiming to evalu-ate and compare the service quality of five major airports in North Africa. The suggested method helps manager of airports know the needs of passengers and the priority of enhancing service items

Fuzzy chance-constrained goal programming model for multi-attribute financial portfolio selection

The aim of this paper is to propose a fuzzy chance constrained goal programming model for solving a multi-attribute financial portfolio selection problem under two types of uncertainty namely randomness and fuzziness. The chance-constrained goals are considered as random variables. The obtained portfolio through this model is the portfolio of the best compromise where the financial decision-maker was asked to make tradeoffs among conflicting and incommensurable attributes such as the expected return, risk and the earning price ratio. The proposed model has been applied to the Tunisian stock exchange market for the period July 2003 to December 2007.Scopu