With this issue, IJPE is entering in the 11th year of its publication. An update on IJPE is provided on page 100 of this issue which tells us that by publishing 52 issues so far (which means on an average of more than 5 issues per year) and by having authors’ footprint over 50 countries of the world, IJPE has established an impressive record of its visibility. During this period, IJPE has published 438 full papers and 50 short communications. By publishing 89 book reviews, IJPE has kept its readers fully informed about the arrivals of the new titles that are available in the literature. IJPE has brought out 22 special issues or sections of an issue involving guest-editors who are well-known specialists in various areas covered by IJPE’s scope during this period. This provide a close interaction between the academia, researchers and practitioners.
In this issue as usual, we present 9 full papers and a short communication, besides providing reviews of three recent books for the benefit of IJPE readers.
The first paper, Technology Qualification Program Integrated with Product Development Process by Maryam Rahimi and Marvin Rausand concerns implementation of a technology qualification program (TQP) which some industries have developed to reduce the uncertainty pertaining to new products development. This paper evaluates and highlights important features of existing TQPs, and proposes a new approach that aims to rectify some weaknesses of the existing approaches.
The second paper, Simultaneous Use of and R Charts for Positively Correlated Data for Medium Sample Size, by Prajapati,presents modified joint and R charts for various levels of correlation. The performance of the joint modified and R chart is measured in terms of average run lengths (ARLs). The ARLs are computed for sample size of 5, using MATLAB software. The simplicity in the design of the joint modified and R chart for various levels of correlation makes it suitable for the industries; where the data are correlated.
The third paper, Estimation of Maximum In-Service Inspection Intervals Based on Risk: A Fuzzy Logic Based Approach, by Chandima Ratnayake proposes a fuzzy logic based expert system for estimating maximum in-service inspection intervals. The estimation of maximum in-service inspection intervals is done based on probability of failure (PoF), consequence of failure (CoF) and currently established values of maximum inspection intervals (MIIs) with respect to different risk levels.
The fourth paper, Particle Swarm Algorithm for Optimization of Complex System Reliability by Sangeeta Pant et.al., a particle swarm optimization algorithm is presented and the performance of the proposed algorithm is tested on some complex engineering optimization problems.
The fifth paper, Early Prediction of Software Fault-Prone Module using Artificial Neural Network,,by Manjubala and Goyal proposes two approaches for the selection of software metrics. First a sensitivity analysis using proposed artificial neural network (ANN) model, named as SA-ANN, is studied and then principal component analysis is used as a tool for dimension reduction with use of ANN model, named as PCA-ANN. The proposed approaches are applied to four NASA datasets to study the effect of scaling on the prediction accuracy.
The sixth paper, Classification of Static Mechanical Equipment using a Fuzzy Inference System: A Case Study from an Offshore Installation, by Seneviratne and Chandima Ratnayake, suggests a fuzzy inference system (FIS) to revise and fine-tune an existing static mechanical equipment classification which has been utilized for the inspection and maintenance of a North Sea P&PF. The proposed approach supports establishing optimal risk-based inspection programs whilst enhancing the quality of in-service inspection programs.
The seventh paper, Bearing Fault Detection based on Stochastic Resonance Optimized by Levenberg-Marquardt Algorithm, by Xinghui Zhang, et al. presents a different method from the existing ones which search the optimal system parameters in a Stochastic Resonance model and uses Levenberg-Marquardt approach which is basically a numeric optimization method to solve this problem. The proposed method is validated by simulation signal and two bearing fault signals.
The eighth paper, Optimum Time-Censored Step-Stress PALTSP with Competing Causes of Failure Using Tampered Failure Rate Model, by Srivastava and Sharma, present a time-censored step-stress partially accelerated life test variable repetitive group sampling (RGS) plan with competing causes of failure using tampered failure rate model and Weibull life distribution. The optimum plan proposed consists in finding out optimum stress change point and optimum sample size by minimizing the average sample number of a lot such that producer’s and consumer’s interests are safeguarded.
The ninth paper, Subset Cut Enumeration of Flow Networks with Imperfect Nodes, by Chakraborty and Goyal, presents a simple approach to consider node failures in reliability evaluation of flow networks using subset cut approach. The method is computationally efficient as it requires less computational time to enumerate subset cuts for networks with imperfect nodes and links compared to other approaches available in the literature.
The last paper which is a short communication, Joint Lot-size and Preventive Maintenance Optimization for a Production System, by Liu et al. presents a framework to solve the optimal lot-size of each product in a production system producing multiple products, together with the optimal preventive maintenance epoch which minimizes the system’s cost rate in long run.