This is the sixth issue of the International Journal of Performability Engineering of the year 2016. We have implemented an on-line paper management system for the journal. The URL is http://ijpe-online.com/ijpe-submission/index.php/IJPE/index. Authors are requested to use this URL for submission of papers for publication. Authors are encouraged to submit their full research papers, case studies, review papers, short communications, book reviews, and other information such as details on conferences within the scope of the journal through the above URL. The journal will be edited by two new Editors-in-Chief starting from January 2017. The new EIC are Dr. Suprasad V. Amari, BAE Systems (suprasad.amari@gmail.com) and Dr. Sanjay K. Chaturvedi, IIT Kharagpur (eic.ijpe@gmail.com).
This issue of the journal consists of eight technical papers, including a short communication, and a book review.
The first paper, Evaluation and Optimization of Overall Equipment Effectiveness on a Pasting Machine in a Battery Manufacturing Industry, focuses on application of OEE to evaluate the performance of critical machines and to determine to what extent the TPM implementation affects the OEE. The procedure to estimate OEE has also been presented through case study which was carried out in industry manufacturing battery for vehicles.
The second paper, Experimental Investigation on Catalytic Properties of Copper Oxide in Internal Combustion Petrol Engine during Cold Start Emission, attempts to study the pollution from multi-cylinder SI engine, using Electrically Heating the Catalyst (EHC) with copper oxide as a catalyst.
The third paper, Productivity Enhancement in a Small Scale Manufacturing Unit through Proposed Line Balancing and Cellular Layout, adopts lean manufacturing techniques to enhance the productivity in gas stove burner manufacturing unit by reduction of lead time. The author has used the Rank position method for line balancing which gives optimum resource allocation for the process based on the Tori Amos Khang Trang time.
The fourth paper, Effects of Reinforcing Elements on the Performance of Laser Transmission Welding Process in Polymer Composites: A Systematic Review, has categorized laser transmission welding methods which are initially introduced to join thermoplastic sheet film and molded objects, and presently applied in industry join polymer composites. The paper has also discussed various properties of the laser transmission welding, its applicability, merits and limitations when applied for industrial cases.
The fifth paper, Approach to Assessment of Maintainability in Design, presents an approach for the evaluation of the maintainability in the design phase presented by its indicator viz. the average repair time while integrating the opinion of the experts for the choice of the parameter of the failure rate.
The sixth paper, Maintenance Priorities for a Repairable System of a Thermal Power Plant Subject to Availability Constraint, presents a methodology to maximize availability of a repairable system. The authors have used a Markov model to compute an availability matrix which provides various availability levels for different combinations of failure and repair rates of all the subsystems. Based upon this, the optimum values of failure and repair rates of each subsystem are obtained and maintenance priorities are decided for all the subsystems of a thermal power plant.
The seventh paper, A Methodology for Risk Assessment and Formulation of Mitigation Strategies for Trucking Industry, identifies various failure modes in the trucking industry and their effects and proposes a modified failure modes and effect analysis (MFMEA) to prioritize the mitigation strategy. The paper proposes to use the modified risk mitigation number (MRMN) approach and to apply interval type-2 Fuzzy FMEA to rank the risk factors. Ranked weightage of the risk factors and personal opinions of the experts have been taken into account for computation of risk mitigation matrix.
The eighth paper, A Cost-Based Maintenance Model based on a Non-Homogeneous Poisson Process, is a short communication. The paper proposes a maintenance model for a deteriorating system subject to vibration monitoring, which is based on a real system of the wind machines from a steel mill. The paper develops a cost model to determine the optimal number of allowable rebalances and the working age of the system and illustrates using a numerical case.
This issue also consists of a book review. The book reviewed is “Lean Six Sigma for Small and Medium Sized Enterprises: A Practical Guide”, Published by CRC Press (2016). This book is authored by Jiju Antony, S. Vinodh and E.U. Gijo.
I hope that the papers in this issue will be informative to the readers and motivate them to do more research in new directions. Suggestions to further improve the journal are most welcome.
I take this opportunity to thank the journal management, in particular Professor Eric Wong, for giving me an opportunity to work for the journal as one of the EICs. I also thank Professor Krishna B. Misra (Founder and long term EIC of the journal), Professor Dianxiang Xu (my Co-EIC), regional editors, assistant editors, editorial board members, authors, paper reviewers, journal subscribers and the readers of the journal for their enthusiasm, encouragement, support, and patience without which the journal could not have achieved its present status. I welcome the new EICs of the journal and wish them all success in bringing the IJPE to newer heights. I also expect that the journal will achieve more and more milestones in the years to come with the active participation and support of all concerned.

Overall Equipment Effectiveness (OEE) is a way to monitor and improve the effectiveness of our manufacturing processes (i.e. machines, manufacturing cells, assembly lines). The purpose of this research is to assess the application of OEE to evaluate the performance of critical machines and to determine to what extent the TPM implementation affects the OEE. The procedure to estimate OEE has also been presented through case study which was carried out in industry manufacturing battery for vehicles. In this experimental study because of excess active material in the pasted grids and the thickness, the boxing will be tight and more active material will also puncture the separator which will result into battery short circuit. Some important corrective measures have mentioned during production and they were forwarded to floor in charge and concern department to verify it and they have noticed it and action was taken under observation. The data collected for a critical machine over a period two month are statistically analyzed to identify the influence of major losses on OEE.

Cold-start emission represents the greatest concentration of emission from today’s catalyst equipped vehicle. The existing catalytic converters are successful in reducing emission after engine warm-up. The catalyst is not active during this warm-up period due to its low operating temperature. The vehicle tail pipe emission can be excessive for a period of one to two minutes following the cold-start. One strategy to reduce the quantity of pollutant emitted during the cold start operation is to have the catalyst active at the time of the engine starts. Electrically Heating the Catalyst (EHC) can help to achieve catalyst activity during the cold-start. This paper deals with the potential of catalytic systems with different volume of catalyst and the presentation of thermal analysis provides insight into the catalytic system. In this investigation, an attempt is being made to study the pollution from multi-cylinder SI engine, using EHC with copper oxide as a catalyst.

Lean manufacturing techniques leads to the elimination of non-value added activities in the industrial ambiance and identifies the current manufacturing procedures, processes to achieve improvement in terms of cost reduction, increase in quality and profit. Lean manufacturing tools are extensively used in industries for recognizing and eliminating the non-value added activities, aiming towards to effective utilization of resources and productivity improvement. Through this research article a study has been made by adopting lean manufacturing techniques to enhance the productivity in gas stove burner manufacturing unit by reduction of lead time. The process flow of existing system is analyzed by using visual study and time study for individual processes. The current layout for the process flow studied and the proposed layout was derived. The proposed layout has been used for successful work flow to meet the future production requirement. To minimize the material movement and reduce work in progress inventory the Kanban storage system was established. Rank position method has been used for line balancing which gives optimum resource allocation for the process based on the Tori Amos Khang Trang time. The proposed layout reduced the material movement from 97 meters to 63 meters and production had also increased by about 20%.

The laser transmission welding was initially introduced to join thermoplastic sheet film and moulded objects. However, presently this welding technique has been brought to the industrial applications to join polymer composites. Unlike polymer-polymer laser transmission welding, optical and thermal properties of reinforcing elements greatly influence the laser transmission welding process of polymer composites. It is dedicated for all reported works that glass fiber causes scattering in composites which reduces the laser intensity of transparent material and thus, glass fiber is not suitable for absorbing laser rather it needs additive such as carbon black to improve laser absorption. Moreover, it is demonstrated here based upon systematic reviewing of laser transmission welding that carbon fiber and carbon nanotubes have very good laser absorption capacities, but not suitable for transparent parts. Moreover, natural fibers are found to inherit some limitations for laser transmission welding including the low processing temperature, prone to chemical reaction due to organic material and laser interaction. Besides, various welding methods are categorized and discussed here.

In a global environment strongly competitive, companies must control the various tools to ensure a maximum competitiveness and must engage in ameliorated actions at all levels. Of this fact, the growing complexity of the systems and the desire to reduce their costs of design, development and operation, make the safety of operation an unavoidable necessity in the development of all industrial systems. In this context, our job is to present an approach to the evaluation of the maintainability in the design phase presented by its indicator of the average repair time while integrating the opinion of the experts for the choice of the parameter of the failure rate.

In the present paper, at a thermal power station, a repairable system consisting of flue gases and air system has been considered for deciding the maintenance priorities. The mathematical equations for solving the system are derived using Chapman–Kolmogorov equation, assuming constant failure and repair rates for all the subsystems. Differential equations are generated, after drawing the transition diagram and then steady state probabilities are determined. After that, the availability matrix is developed, which provides various performance/availability levels for different combinations of failure and repair rates of all the subsystems. Based upon various availability values and graphs of failure/repair rates of different subsystems, performance and optimum values of failure/repair rates for maximum availability of each subsystem are analyzed. Consequently maintenance priorities are decided for all the subsystems of a thermal power plant.

Trucking is the backbone of Indian freight transportation as 63% freight movement is carried out via road. Trucking industry needs to focus on the operational efficiency, but at the same time, it is extremely important to minimize the likelihood of occurrence of the risk events with a strategic risk response plan during operation of the industry. Indian trucking industry is facing many risky situations such as fragmentation in the industry, underutilization of trucks, shortage of drivers and many others issues. To compete and sustain in the globalized scenario, it is necessary to quantify the perilous situations facing the trucking industry and develop an appropriate mitigation plan to handle such situations. This paper identifies various failure modes of trucking industry, their effects and possible actions for risk mitigation. The paper also proposes a Modified Failure Modes and Effect Analysis (MFMEA) to prioritize the mitigation strategy, using Modified Risk Mitigation Number (MRMN) approach and applies Interval type-2 Fuzzy FMEA to rank the risk factors. The proposed approach takes into account the ranked weightage of the risk factors and personal opinions of the experts for computation of risk mitigation matrix.

It has been well-known that the maximum likelihood estimation method is based on the large sample size and the estimator is biased. For Weibull distribution, the maximum likelihood estimators don’t have explicit expression; This weakness complicates the correctness on the biasness. A moment method that has explicit expression for estimators of Weibull distribution has been developed by Sirvanci and Yang. This method was developed from mathematical perspective, especially for right censored situation. This paper elaborates this moment method, and develops confidence interval for unknown parameter and reliability function. Proofs of some key formulas, which are missed in the state-of-art, are presented in this paper. Simulation results show this moment method is closer to true parameters than the classical maximum likelihood estimation.

This paper considers a maintenance model for a deteriorating system subject to vibration monitoring, which is based on a real system of the wind machines from a steel mill. The system is replaced according to two thresholds: the number of allowable rebalances (i.e., maintenance activities) N, or the working age of the system T, whichever comes first. Once the system’s vibration measurement exceeds a specific value, a maintenance activity is carried out to restore the system to a better (but not “as new”) condition. This implies that the maintenance is imperfect and as such the operating interval after each maintenance action decreases stochastically. We develop a cost model to determine the optimal N and T, as shown by a numerical case example.