Purpose

Modularization and level of repair analysis for fleet system influences every phase of the system life cycle. Modular based fleet system design raises new issues since the maintenance/repair services introduces further requirements than traditional product engineering. The decision of modular system and level of repair plays an important role to reduce the Life Cycle Costs (LCC) of fleet maintenance system. The concept of modularity has been extended to services in maintenance for the varieties of fleet systems such as wind turbines, gas turbines, advance machine tools and aircrafts etc. System modularity allows the designers to use of different design alternatives and ease of fault diagnosis, repair and services. The purpose of this paper to develop a joint optimization approach for optimal selection of modular design and level of repair decisions. Usually these two decisions are taken separately.

Design/methodology/approach

In the proposed joint approach, level of repair analysis is used to obtain the optimal modular design decisions with reduced life cycle cost. In the existing research, the effect of system modularity on the level of repair decisions is investigated. The simulation-based approach is used to solve this joint problem. Which is rarely seen in the existing literature. A genetic algorithm-based simulation is used to investigate the joint problem. The proposed approach also evaluates all the possible configurations of modular design to justify the integrated effect of modularity and maintenance decisions, that is Level of Repair (LOR).

Findings

This paper highlights interactive effect of system modularity and level of repair decisions for the system operated in multi-echelon maintenance network. A comparative study is provided on effect of system modularity and level of repair decisions considering the time dependent failure rate and constant failure rate of the system components. A simulation based joint approach is used to solve this problem. The results obtained from the investigation are shown that modularity plays an important role to allocate modularity and level of repair decisions for the fleet system. The novelty of this research work is to identify the role of modularization to optimizing the level of repair decisions. The models, that is time-dependent failure rate and constant failure rate presented in this study provides more practical approach to deal the modularity and level of repair analysis.

Research limitations/implications

The proposed joint approach illustrates using a numerical case of a mechanical system operated at fleet level. More modular structure in terms of number of modules in the machine may be presented for an industrial case. Additionally, the joint approach can also be extended for the any other consumer product and system. But, the prime motive of the paper is to highlights the importance of the modular design while selecting the level of repair decisions.

Originality/value

This is the first work which consider the joint optimization of modular design and level of repair analysis to the best of authors knowledge. Present paper is a more practical approach for identifying the modular design and level of repair decisions for the system operated at fleet level.

中文翻译：

---

考虑零件故障率的基于仿真的车队系统模块化和维修决策联合优化

目的

车队系统的模块化和维修分析水平会影响系统生命周期的每个阶段。基于模块的车队系统设计提出了新的问题，因为维护/维修服务提出了比传统产品工程更高的要求。模块化系统的决定和维修水平在降低车队维护系统的生命周期成本（LCC）中起着重要作用。模块化的概念已扩展到各种机队系统的维护服务，例如风力涡轮机，燃气轮机，先进的机床和飞机等。系统模块化允许设计人员使用不同的设计替代方案，并且易于进行故障诊断，维修。和服务。本文的目的是开发一种联合优化方法，以优化模块设计和维修决策水平。通常，这两个决定是分开做出的。

设计/方法/方法

在提出的联合方法中，使用维修分析级别来获得最优的模块化设计决策，同时降低生命周期成本。在现有研究中，研究了系统模块化对维修决策水平的影响。基于仿真的方法用于解决此联合问题。在现有文献中很少见到。基于遗传算法的仿真用于研究关节问题。提出的方法还评估了模块化设计的所有可能配置，以证明模块化和维护决策的综合效果是合理的，即维修水平（LOR）。

发现

本文重点介绍了在多级维护网络中运行的系统的系统模块化和维修决策水平的交互作用。考虑到时间依赖性故障率和系统组件的恒定故障率，对系统模块化效果和维修决策水平进行了比较研究。基于仿真的联合方法用于解决此问题。从调查中获得的结果表明，模块化在为车队系统分配模块化和维修决策水平方面起着重要作用。这项研究工作的新颖性在于确定模块化对优化维修决策水平的作用。模型，

研究局限/意义

提出的联合方法说明了在机队级别上运行的机械系统的数值情况。对于工业情况，可以提出机器中模块数量更多的模块化结构。另外，联合方法也可以扩展到任何其他消费产品和系统。但是，本文的主要动机是在选择维修决策级别的同时强调模块化设计的重要性。

创意/价值

这是第一篇研究，结合作者的知识，考虑了模块化设计和维修分析水平的联合优化。本论文是一种更实用的方法，可为舰队级别的系统识别模块化设计和维修决策级别。