This paper considers a general repairable product sold under a failure-free renewing warranty agreement. In the case of a general repairable model, there can be two types of failure: type I failure (a minor failure), which can be rectified by minimal repairs; and type II failure (a catastrophic failure), which can be removed only by replacement. After a minimal repair, the product is operationa...

Às 12 horas, 28 minutos e 25 segundos do dia de janeiro 2019, a Barragem 1, localizada na mina Córrego Feijão, da mineradora Vale, em Brumadinho (MG), se rompeu. A tragédia ocorreu no horário que é apresentado o telejornal MG1, Globo Minas. Por meio Análise Materialidade Audiovisual (COUTINHO, 2016; 2020), verificamos como MG1 cobriu os três primeiros aniversários rompimento barragem, diz respe...

In this paper, we study the tail behavior of the stationary queue length of an M/G/1 retrial queue. We show that the subexponential tail of the stationary queue length of an M/G/1 retrial queue is determined by that of the corresponding M/G/1 queue, and hence the stationary queue length in an M/G/1 retrial queue is subexponential if the stationary queue length in the corresponding M/G/1 queue i...

There are some problems with estimating the time required for the manufacturing process of products, especially when there is a variable serving time, like control stage. These problems will cause overestimation of process time. Layout constraints, reworking constraints and inflexible product schedule in multi product lines need a precise planning to reduce volume in particular situation of lin...

This paper aims at providing a parameter estimation method for the machine tool reliability analysis to overcome the problem of unavailability of a well-defined failure data collection mechanism. It uses the knowledge and experience of maintenance personnel to obtain the parameters of lifetime distribution of the repairable as well as non-repairable components/ subassemblies. It is further deve...

This paper attempts to provide a more realistic approach to the characterization of system reliability when handling redundancy allocation problems: it considers repairable series-parallel systems comprised of components subjected to corrective maintenance actions with failure-repair cycles modeled by renewal processes. A multiobjective optimization approach is applied since increasing the numb...

A non-empty set F of n-bit vectors over alphabet {0, 1} is called singly repairable, if every vector u ∈ F satisfies the following conditions: (i) if any bit of u is changed (from 0 to 1 or vice versa), the new vector does not belong to F (ii) there is a unique choice of a different bit that can then be changed to give another vector 6= u in F . Such families F exist only for even n and we show...

Aim: The aim of this study was to assess the fracture resistance endodontically treated maxillary premolars with mesioocclusodistal (MOD) cavities supported by horizontal glass fiber posts. Methodology: Thirty three extracted were collected and grouped into three. MOD prepared all them treated. Teeth posts; vertical posts composite restoration alone in groups respectively. Fracture assessed usi...

A complex repairable system generally adopts multi-grade preventive maintenance. The optimization of maintenance decision making is usually regarded as a complex mathematical problem. This study proposes a three-grade preventive maintenance optimization method for complex repairable system based on field failure data. Specifically, all failures are classified into three categories: minor, moder...