Journal of Industrial Engineering The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. A Study of Time Series Model for Predicting Jute Yarn Demand: Case Study Thu, 27 Jul 2017 00:00:00 +0000 In today’s competitive environment, predicting sales for upcoming periods at right quantity is very crucial for ensuring product availability as well as improving customer satisfaction. This paper develops a model to identify the most appropriate method for prediction based on the least values of forecasting errors. Necessary sales data of jute yarn were collected from a jute product manufacturer industry in Bangladesh, namely, Akij Jute Mills, Akij Group Ltd., in Noapara, Jessore. Time series plot of demand data indicates that demand fluctuates over the period of time. In this paper, eight different forecasting techniques including simple moving average, single exponential smoothing, trend analysis, Winters method, and Holt’s method were performed by statistical technique using Minitab 17 software. Performance of all methods was evaluated on the basis of forecasting accuracy and the analysis shows that Winters additive model gives the best performance in terms of lowest error determinants. This work can be a guide for Bangladeshi manufacturers as well as other researchers to identify the most suitable forecasting technique for their industry. C. L. Karmaker, P. K. Halder, and E. Sarker Copyright © 2017 C. L. Karmaker et al. All rights reserved. Effectiveness of Physical Barriers Installation for Prevention of Incidents in Mexico City’s Subway System Sun, 18 Jun 2017 00:00:00 +0000 Nowadays, suicides inside the installations of subway platforms are considered a public health problem in Mexico City. One solution to prevent them is the installation of physical barriers, but their high cost is unattractive for governmental authorities. Traditional approaches of research on the effectiveness of physical barriers for preventing suicides have been limited to analyzing statistically the effects of installing platform screen doors and blue lights on subway platforms. Although considerable progress has been made in this field, many important issues remain unexplored. This study investigates the effectiveness of physical barriers installation for prevention of incidents in Mexico City subway system by means of an agent-based simulation model. Firstly, the design of physical barriers for prevention of incidents in Mexico City subway system is described. Secondly, a conceptual model of the Zócalo station subway platform is presented. Thirdly, an agent-based simulation model of Zócalo station subway platform is implemented using AnyLogic™ software considering normal operations of the subway station. This study shows that physical barriers installation on the Zócalo subway platform can effectively prevent 76% of passenger’s suicides. Gerardo de Jesús Portillo-Villasana, Aida Huerta-Barrientos, and Yazmin Dillarza Andrade Copyright © 2017 Gerardo de Jesús Portillo-Villasana et al. All rights reserved. Machine Learning-Based Parameter Tuned Genetic Algorithm for Energy Minimizing Vehicle Routing Problem Wed, 18 Jan 2017 08:08:00 +0000 During the last decade, tremendous focus has been given to sustainable logistics practices to overcome environmental concerns of business practices. Since transportation is a prominent area of logistics, a new area of literature known as Green Transportation and Green Vehicle Routing has emerged. Vehicle Routing Problem (VRP) has been a very active area of the literature with contribution from many researchers over the last three decades. With the computational constraints of solving VRP which is NP-hard, metaheuristics have been applied successfully to solve VRPs in the recent past. This is a threefold study. First, it critically reviews the current literature on EMVRP and the use of metaheuristics as a solution approach. Second, the study implements a genetic algorithm (GA) to solve the EMVRP formulation using the benchmark instances listed on the repository of CVRPLib. Finally, the GA developed in Phase 2 was enhanced through machine learning techniques to tune its parameters. The study reveals that, by identifying the underlying characteristics of data, a particular GA can be tuned significantly to outperform any generic GA with competitive computational times. The scrutiny identifies several knowledge gaps where new methodologies can be developed to solve the EMVRPs and develops propositions for future research. P. L. N. U. Cooray and Thashika D. Rupasinghe Copyright © 2017 P. L. N. U. Cooray and Thashika D. Rupasinghe. All rights reserved. Inventory Control Systems Model for Strategic Capacity Acquisition Sun, 27 Nov 2016 13:55:48 +0000 Variation of installed industrial capacity has been found to follow a cyclic pattern. This paper discusses the application of control theory to the problem of the timely acquisition of extra production capacity. The control system based model presented here is compared with a System Dynamics model proposed by Sterman. Key differences are the method of implementing rational decisions about deployment of extra capacity and the use of a nonlinear APVIOBPCS inventory model. Benefits of this new model are a more measurable process and the ability to select parameter values to optimise capacity deployment. Simulation of the model indicates that the results found by Sterman underestimate the production backlog and time taken to reach equilibrium. The use of a Proportional, Integral, and Derivative (PID) controller in the capacity control loop model illustrates that it is possible not only to alter the backlog levels but at the same time to reduce the sales force and improve the revenue. The model also shows clearly that the impact of not increasing capacity promptly results in catastrophic failure of sales as a structural, rather than a business, problem. This model is simple enough to be implemented as a spreadsheet for use as a guide by managers. Anthony S. White and Michael Censlive Copyright © 2016 Anthony S. White and Michael Censlive. All rights reserved. A Framework to Measure the Service Quality of Distributor with Fuzzy Graph Theoretic Approach Mon, 26 Sep 2016 06:15:41 +0000 A combination of fuzzy logic and graph theoretic approach has been used to find the service quality of distributor in a manufacturing supply chain management. This combination is termed as the fuzzy graph theoretic (FGT) approach. Initially the identified factors were grouped by SPSS (statistical package for social science) software and then the digraph approach was applied. The interaction and inheritance values were calculated by fuzzy graph theory approach in terms of permanent function. Then a single numerical index was calculated by using permanent function which indicates the distributor service quality. This method can be used to compare the service quality of different distributors. Tarun Kumar Gupta and Vikram Singh Copyright © 2016 Tarun Kumar Gupta and Vikram Singh. All rights reserved. Development of a Pneumatically Driven Cell for Low Cost Automation Thu, 08 Sep 2016 18:09:39 +0000 The present work addresses the development of a pneumatically driven manufacturing cell for low cost automation applications. This cell can be used in innovative applications as a low cost alternative to increase production and quality in industry. The state of the art shows that technological advances in computing have made possible a drop in equipment prices, making them more accessible. The aim of this work is to develop automation through a classic methodology for a manufacturing cell to minimize errors and facilitate the sequential logic conception. This experimental prototype has been developed at the UNIJUI with financial support by public organizations and companies. Pneumatic actuator used in bench driven has the following advantages: its maintenance is easy and simple, is of relatively low cost, self-cooling properties, and good power density (power/dimension rate), and is fast acting with high acceleration and installation flexibility. However, there are difficulties of control logic due to the complex systems. The sequential controller strategy design considers the pneumatic system, experimental results, and performance of the proposed control strategy. Antonio Carlos Valdiero, Ivan Jr. Mantovani, Andrei Fiegenbaum, Giovani P. B. Dambroz, and Luiz A. Rasia Copyright © 2016 Antonio Carlos Valdiero et al. All rights reserved. Development of a Layout Model Suitable for the Food Processing Industry Mon, 23 May 2016 06:37:45 +0000 The food processing industry is a subset of the manufacturing sector with unique challenges. Among these, ensuring food hygiene and preventing contamination are two issues of prime importance. Hence, designers have to overcome such challenges when designing facilities suitable for food processing. The paper formulates a model that simplifies the layout planning process for the food processing facilities (FPF) in order to help the designers. A generalised framework that helps to visualise the Facilities Layout Problem (FLP) was initially developed. A layout model for FPF was then developed considering the unique features that need to be present in the layout. The model classifies the areas of FPF into five: primary, secondary, utilities, warehouse, and administration based on the activities and the level of risk present in food processing. It further proposes specific locations for the five sections in the factory layout. In order to test the performance of the framework and the model, a case study was conducted in a malted milk powder processing facility in Sri Lanka by changing its layout according to the proposed model. The framework and the model showed promise in its implementation. However, the approach and the layout model need to be evaluated in further cases in order to ascertain their usability and performance. W. N. C. Wanniarachchi, R. A. R. C. Gopura, and H. K. G. Punchihewa Copyright © 2016 W. N. C. Wanniarachchi et al. All rights reserved. Application of Systems Simulation for Predicting and Optimising Energy Requirements for HDF Production Wed, 07 Oct 2015 08:05:31 +0000 Even though simulation has been used so far in manufacturing facilities for modelling supply chain management, production management, and business processes, its applications in managing the energy consumption within manufacturing companies represent a new and innovative research domain. This prompted the research undertaken for the work present in this paper. The main focus of this research is to analyse production management in a manufacturing facility and correlate it with the energy consumption. The research initially concentrates on different simulation methodologies and their application in the current manufacturing domain. Literature relating to the correlation of energy consumption with production management has also been reviewed. This review identified very few previous instances where simulation tools were used to predict the energy consumption in a manufacturing facility. This research brings a novel approach to investigating the adaptability of industrial simulation processes and tools for modelling the energy consumption with respect to a variable production output. The end result of this investigation consists of a better understanding of the production system and the energy losses that were captured by the simulation model. Cristina Maria Luminea, John Donovan, and David Tormey Copyright © 2015 Cristina Maria Luminea et al. All rights reserved. A Quality Function Deployment (QFD) Approach in Determining the Employer’s Selection Criteria Tue, 08 Sep 2015 11:31:34 +0000 The industrial training program is part of the academic curriculum at the tertiary level. It plays an important role in providing students with the exposure to a real working environment in the industry. Through this program, the higher education institutions (HEI) could identify the gaps in the curriculum based on the requirements from the industry. In addition, the feedback from the industry will help the HEI to equip students with relevant skills according to the demands from the industry. Indirectly, it can help to address the issue of unemployed graduates of which the number seems to increase from time to time. Therefore, this study aims to obtain the feedback from the employers out there in order to determine the most preferred criteria in selecting students for the industrial training placement by using Quality Function Deployment (QFD) approach. The findings, through the development of house of quality based on the QFD approach, show that communication skills and students’ participation in sports and cocurricular activities at their university are the most preferred selection criteria. Therefore, the QFD approach can be used to translate the employers’ feedback in improving the marketability of the students in the industry. Nora Muda and Noor Sulawati Mat Roji Copyright © 2015 Nora Muda and Noor Sulawati Mat Roji. All rights reserved. Developing an Inspection Optimization Model Based on the Delay-Time Concept Thu, 02 Jul 2015 07:04:53 +0000 Infrastructures are considered as important facilities required for every country and society to be able to work properly. Aging and deterioration of such structures during their lifetime are a major concern both for maintenance researchers in the academic world and for the practitioners. This concern is mainly because the deterioration increases the maintenance costs dramatically and lowers the reliability, availability, and safety of the structural system. Preventive maintenance and inspection activities are the most usual means for keeping the structure in a good condition. This paper utilizes the concept of delay-time for developing the optimal inspection policy for deteriorating structures. In the proposed stochastic model, discrete times of inspection activities are taken as the decision variables of an optimization problem, in a way that the obtained aperiodic (nonuniform) inspection schedule minimizes the total downtime ratio of the structure. To illustrate the model capabilities, various numerical examples are solved and results are compared with the traditional periodic (uniform) inspection policies. The results indicate the substantial reduction in system downtime due to the wisely planned inspection schedule and the appropriate utilization of delay-time concept, which is indeed a powerful framework for inspection optimization problems. Ehsan Nazemi and Kamran Shahanaghi Copyright © 2015 Ehsan Nazemi and Kamran Shahanaghi. All rights reserved. Robust Design Optimization of a 4-UPS-S Parallel Manipulator for Orientation-Regulating Control System of Solar Gather Panels Tue, 17 Mar 2015 14:08:19 +0000 This paper proposes a redundantly actuated parallel manipulator 4-UPS-S that is applicable for orientation adjustment in the gathering process of solar power. A thorough analysis involving the kinematic issues is performed. Inverse kinematic problems are solved in the close-loop. The Jacobian matrix and some performance indexes are analytically derived. The multiobjective optimization model is established, and the determinacy optimization is completed on the basis of previous research works. Six-Sigma robust analysis is performed on the basis of the determinacy optimal solution. Results show that 4-UPS-S does not satisfy the quality requirement. Therefore, it is necessary to implement Six-Sigma robust optimization, and select optimial solution of robustness to complete the nondeterminacy optimization. The research results show that the proposed methodology has a simple operation and high optimization efficiency. The methodology commodiously obtains robustness parallel manipulator that satisfies the quality requirement. Guohua Cui, Haidong Zhou, Haiqiang Zhang, Dan Zhang, and Yanwei Zhang Copyright © 2015 Guohua Cui et al. All rights reserved. Regression Model to Estimate Standard Time through Energy Consumption of Workers in Manual Assembly Lines under Moderate Workload Tue, 17 Feb 2015 11:34:05 +0000 We propose a Standard Time (ST) Estimate Model based on energy demand to attain more equal work distribution in manual assembly lines. The proposal was developed estimating the energy consumption by monitoring the heart rate (HR) of 84 people between 18 and 48 years old while performing repetitive activities under moderate workload (2.5–5.0 kilocalories/minute (Kcal/min)). Variables on one model were determined, which were based on energy consumption (EC) using the 13-variable Best-Subset function. Subsequently, a general equation for the Standard Time (ST) Estimate Model was calculated through lineal regression. Two significant variables were obtained: total kilocalories (Kcal tot.)/pieces and total Kcal/operation time (OT) for each station, which are included in a Standard Time Estimate Model. ST can be represented with a regression model measuring the total number of kilocalories consumed by workers and the OT, which can help companies to balance the cycle time in their assembly lines. Abdul Ayabar, Jorge De la Riva, Jaime Sanchez, and Cesar Balderrama Copyright © 2015 Abdul Ayabar et al. All rights reserved. Ergonomic Study and Design of the Pulpit of a Wire Rod Mill at an Integrated Steel Plant Thu, 12 Feb 2015 12:21:47 +0000 This paper presents ergonomic study and design of the pulpit in a wire rod mill at an integrated steel plant. The mill was facing problem of less productivity of workers due to lack of proper work posture and working conditions. The study data were collected from the interview of seven operators involved with the pulpit. Relevant ergonomic tools were used for assessing the survey data for identifying the risk factors involved with these operators. Ergonomically improved pulpit was proposed for reducing the musculoskeletal disorders (MSDs) thereby increasing the productivity of the plant. Chandra P. Dewangan and Arun K. Singh Copyright © 2015 Chandra P. Dewangan and Arun K. Singh. All rights reserved. A Sustainable Manufacturing Strategy from Different Strategic Responses under Uncertainty Tue, 10 Feb 2015 11:23:21 +0000 This paper presents a decision framework that highlights the integration of manufacturing strategy (MS) and sustainability along with strategic responses as a significant component. This integration raises complexity and uncertainty in decision-making following the number of subjective components with their inherent relationships that must be brought into context and the huge amount of required information in eliciting judgments. Thus, a proposed hybrid multicriteria decision-making (MCDM) approach in the form of an integrated probabilistic fuzzy analytic network process (PROFUZANP) is adopted in this work. In this method, analytic network process (ANP) serves as the main framework in identifying policy options of manufacturing strategy. Fuzzy set theory (FST) is used to describe vagueness in decision-making which is carried out by eliciting judgments in pairwise comparisons using linguistic variables with corresponding triangular fuzzy numbers (TFNs). Probability theory is used to handle randomness in aggregating judgments of multiple decision-makers. Results show that a stakeholder-oriented approach is considered the most relevant strategic response in developing a sustainable manufacturing strategy. The contribution of this work lies in identifying the policies which constitute a sustainable manufacturing strategy using an integrated MCDM approach under uncertainty. Lanndon Ocampo, Eppie Clark, and Kae Vines Tanudtanud Copyright © 2015 Lanndon Ocampo et al. All rights reserved. Factor Analysis of Obstacles Restraining Productivity Improvement Programs in Manufacturing Enterprises in Oman Thu, 13 Nov 2014 00:00:00 +0000 Manufacturing enterprises can face obstacles that make productivity improvement efforts ineffective or even prevent improvement operations. This paper reports on an investigation of the internal obstacles restraining productivity improvement programs in the manufacturing enterprises of developing countries, using Oman as a case study. Data required for this study were collected through a questionnaire given to production and operations managers at 51 manufacturing enterprises in Oman. The results of applying factor analysis to a dataset of 15 obstacles showed that these obstacles can be reduced to three major factors. Ranked according to their importance, these factors are poor management practices, employee job dissatisfaction, and poor human resource management. The findings of this research are of value to production and operations managers of manufacturing enterprises who are interested in conducting productivity improvement programs not only in Oman but also in developing countries with environments similar to that of Oman, such as the Gulf Cooperation Council (GCC) countries. Hamdi A. Bashir, Khalid Alzebdeh, and Amur M. A. Al Riyami Copyright © 2014 Hamdi A. Bashir et al. All rights reserved. Multiobjective Scheduling of Remote-Area Employees with Minimum Cost of Transportation Wed, 12 Nov 2014 12:42:46 +0000 An integer programming model and optimal solution procedure are presented for assigning employees to the (10, 14) days-off schedule. This schedule is used by a large oil company to schedule employees in remote work locations. The primary objective is to minimize the total number of employees. Since employees are flown to their remote work sites, the company also aims to minimize transportation cost. Therefore, secondary objectives include (1) minimizing the number of active days-off work patterns, (2) consistently using the same set of active days-off patterns, (3) assigning work schedules fairly among employees, and (4) avoiding the use of specialized optimization solvers. A rotation schedule is used in which two scheduling rules are enforced: a minimum proportion of weekend days off needs to be given and a maximum limit on the number of successive workdays cannot be exceeded. Utilizing the problem structure, simple optimal procedures are developed to solve this unique complex scheduling problem. Hesham K. Alfares Copyright © 2014 Hesham K. Alfares. All rights reserved. Validation of Methods for the Optical Characterisation of the Wettability of Polymeric Films for Food Packaging Thu, 23 Oct 2014 00:00:00 +0000 A methodology is described for the theoretical-experimental evaluation of the measurement uncertainty of the polar and dispersive components of the surface free energy (SFE) in polypropylene films; these parameters are related to the film wettability of adhesives and inks. The proposed method is based on the measurement by means of a vision system of the contact angles of liquid drops deposited on the film itself, which allows for obtaining, through mathematical models drawn from the literature, the physical quantities of interest. The effect of the principal influence parameters has been experimentally evaluated, and testing has allowed the defining of the technical procedures readily transferable in the industry. The uncertainty assessment is interesting not only to correctly evaluate experimental data but also to characterise the reproducibility of the effects of techniques for improving the wettability of films, such as surface treatments. Giulio D’Emilia and Emanuela Natale Copyright © 2014 Giulio D’Emilia and Emanuela Natale. All rights reserved. Theoretical Foundations of Efficiently Organizing Production Processes: Using the Example of Combining Organizational Forms of Component Manufacture and Internal Transport Wed, 22 Oct 2014 13:09:17 +0000 This paper examines the problem of efficient production processes organization down to subprocesses levels. Subtasks of production within subprocesses necessitate a specific set of requirements for production organization. Through particular features and their respective characteristics, these requirements are further systemized and described as process types. The main manufacturing process “component manufacture” and its connected production support service “internal transport” have been chosen as examples to show relevant organizational principles and forms. From this baseline and together with a decision algorithm, selected organizational options and a combination thereof shall lead to theoretically optimized solutions which meet all predefined requirements. A multilevel organizational alignment model lays out interdependencies of combined process type-oriented organizational forms. Methods of comparative organizational profile analysis in support of reengineering approaches are systemized and further developed towards resulting organizational adaptations. Anne-Katrin Schroeder, Theodor Nebl, and Christian Mainzinger Copyright © 2014 Anne-Katrin Schroeder et al. All rights reserved. Supply Chain Integration in the Manufacturing Firms in Developing Country: An Ethiopian Case Study Tue, 21 Oct 2014 13:57:46 +0000 With the advancement of information and communication technologies, supply chain integration has been considered a strategic tool for firms to improve their competitiveness. The supply chain integration within processes and between organizations has enhanced value creation. However, the fragmented nature of the business in developing country demonstrates a noticeable difficulty in terms of competitiveness and efficiency. Lack of a relevant literature on practical experience in supply chain integration in developing countries is one of the challenges. The purpose of this research is to identify the level of interorganizational and intraorganizational supply chain integration practices. It also analyzes the challenges faced in the manufacturing firms in developing countries. The methodology followed a thorough review of literature and semistructured interviews amongst the Ethiopian manufacturing industries. The preliminary findings of the study highlight that prevailing approach to supply chain integration is limited to ad hoc functional based boundaries within the firm. The SC integration enablers are also restricted to the traditional way of communications such as telephone, fax, and letters. Firms need to focus on those issues that require attention in pursuance of greater SC integration. Fasika Bete Georgise, Klaus-Dieter Thoben, and Marcus Seifert Copyright © 2014 Fasika Bete Georgise et al. All rights reserved. An EOQ Model for Phase Inventory with Induced Demand and Periodic Cycle Time Tue, 16 Sep 2014 11:19:30 +0000 This paper deals with a stock flow of an inventory problem over induced demand. The inventory is consumed through “core customer” or chain marketing system in an induced environment (inductance) to exhaust all the items of the stock inventory in an indefinite time. The demand rate is depicted due to induced factor which is generated from the same inventory presented nearby. The inventory cycle time is split into several periodic times due to oscillatory feature of the inventory which is called phase inventory. Considering uniform demand, this cycle time splits into two basic parts, namely, “first shift” (phase) and “second shift” (phase). Since the process dampens over time, so the whole inventory will exhaust after few periods. A cost function consisted of inventory cost, setup cost, and loss for induced items is minimized to obtain optimal order quantity and replenishment time. The multivariate lagrange interpolation (MLI) over the average values of the postsensitivity analysis is developed here. Finally, graphical illustrations are made to justify the model. Sujit Kumar De, Shib Sankar Sana, and Adrijit Goswami Copyright © 2014 Sujit Kumar De et al. All rights reserved. Measurement of Overall Performance Effectiveness in Setup Improvement Thu, 11 Sep 2014 12:35:30 +0000 This study aimed to improve the setup process of injection molding machines by using the developed setup improvement methodology. Overall performance effectiveness (OPE) was used to evaluate the setup improvement. A case study was tested on the application of the developed setup improvement methodology. A 50.1% reduction in setup time was attained by the developed methodology, and significant time savings were achieved with minimum investment. Comparisons between before and after improvement implementation were conducted through OPE to verify the improvement. In terms of OPE, the setup performance in the case study considered an acceptable value of 60.45%. The setup process performance of the developed setup improvement methodology was judged in terms of effectiveness. Results therefore indicate that OPE measurement is an effective way to analyze the efficiency of a single setup process. Shye-Nee Low, Siu-Hou Chong, Hui-Yee Sim, Solehhudin Razalli, and Shahrul Kamaruddin Copyright © 2014 Shye-Nee Low et al. All rights reserved. Optimal Pricing and Ordering Policy for Two Echelon Varying Production Inventory System Thu, 11 Sep 2014 12:14:40 +0000 The paper proposes a two-stage supply chain model for price sensitive demand in imperfect production system while manufacturer and supplier are the members of the chain. The supplier screens the raw materials first and supplies good materials to the manufacturer at a constant rate. The production rate varies randomly within a finite interval. The inventory cycle of the manufacturer starts with shortages and production and it finishes with shortages again, in which shortages are partially backlogged. We consider a mixture of LIFO (last in, first out) and FIFO (first in, first out) dispatching policies to fill the backlogged demand. Thus, the objective of the proposed paper is to determine the optimal ordering lot-size and selling price of the manufacturer such that the per unit average integrated expected profit of the supply chain model is maximized. A numerical example is provided to analyze and illustrate the behavior and application of the model. Finally, sensitivity analysis of the key parameters are presented to test feasibility of the model. Brojeswar Pal, Shib Sankar Sana, and Kripasindhu Chaudhuri Copyright © 2014 Brojeswar Pal et al. All rights reserved. Analysis of Shop Floor Performance through Discrete Event Simulation: A Case Study Mon, 08 Sep 2014 07:58:10 +0000 Shop floor performance management is a method to ensure the effective utilization of people, processes, and equipment. Changes in the shop floor might have a positive or negative effect on production performance. Therefore, optimal shop floor operation is required to enhance shop floor performance and to ensure the long-term efficiency of the production process. This work presents a case study of a semiconductor industry. The punching department is modeled to investigate the effect of changes in the shop floor on production performance through discrete event simulation. The effects on the throughput rate, machine utilization, and labor utilization are studied by adjusting the volume of parts, number of operators, and flow pattern of parts in a series of models. Simulation results are tested and analyzed by using analysis of variance (ANOVA). The best model under changes in the shop floor is identified during the exploration of alternative scenarios. Yeong Wei Ng, Joshua Chan Ren Jie, and Shahrul Kamaruddin Copyright © 2014 Yeong Wei Ng et al. All rights reserved. Minimizing the Number of Tardy Jobs on a Single Machine with an Availability Constraint Mon, 01 Sep 2014 06:10:18 +0000 Most scheduling problems are based on the assumption that machines work continuously during the planning horizon. This assumption is not true in many production environments because the machine may not be available during one or more periods such as during breakdowns or maintenance operations. In this paper, the problem of the single machine scheduling with one unavailability period and nonresumable jobs with the aim of minimizing the number of tardy jobs is studied. A number of theorems are proved and a heuristic procedure is developed to solve the problem. A branch-and-bound approach is also presented which includes upper and lower bounds and efficient dominance rules. Computational results for 2680 problem instances show that the branch-and-bound approach is capable of solving 98.7% of the instances optimally, bearing witness to the efficiency of the proposed procedure. Our results also indicate that the proposed approaches are more efficient when compared to other methods. Ehsan Molaee and Ghasem Moslehi Copyright © 2014 Ehsan Molaee and Ghasem Moslehi. All rights reserved. Logistics Service Provider Selection through an Integrated Fuzzy Multicriteria Decision Making Approach Mon, 16 Jun 2014 13:20:45 +0000 Nowadays, the demand of third-party logistics provider becomes an increasingly important issue for companies to improve their customer service and to decrease logistics costs. This paper presents an integrated fuzzy approach for the evaluation and selection of 3rd party logistics service providers. This method consists of two techniques: (1) use fuzzy analytic hierarchy process to identify weights of evaluation criteria; (2) apply fuzzy technique for order preference by similarity to ideal solution (TOPSIS) method to evaluate and sequence alternatives and to make the final selection. Finally, an actual industrial application is performed in logistics department of a tire manufacturing company. For this, first, eight logistics supplier selection criteria were determined, and then the best alternative among seven logistics service provider companies was selected by the proposed method. Gülşen Akman and Kasım Baynal Copyright © 2014 Gülşen Akman and Kasım Baynal. All rights reserved. A Multiobjective Iterated Greedy Algorithm for Truck Scheduling in Cross-Dock Problems Thu, 08 May 2014 00:00:00 +0000 The cross-docking system is a new distribution strategy which can reduce inventories, lead times, and improve responding time to customers. This paper considers biobjective problem of truck scheduling in cross-docking systems with temporary storage. The objectives are minimizing both makespan and total tardiness. For this problem, it proposes a multiobjective iterated greedy algorithm employing advance features such as modified crowding selection, restart phase, and local search. To evaluate the proposed algorithm for performance, it is compared with two available algorithms, subpopulation particle swarm optimization-II and strength Pareto evolutionary algorithm-II. The comparison shows that the proposed multiobjective iterated greedy algorithm shows high performance and outperforms the other two algorithms. B. Naderi, Shadi Rahmani, and Shabnam Rahmani Copyright © 2014 B. Naderi et al. All rights reserved. Applicability of Tool Condition Monitoring Methods Used for Conventional Milling in Micromilling: A Comparative Review Mon, 28 Apr 2014 08:01:38 +0000 Micromilling is a contact based material removal process in which a rotating tool with nose radius in microns is fed over a stationary workpiece. In the process small amount of material gets chipped off from the workpiece. Due to continuous contact between tool and workpiece significant damage occurs to the cutting tools. Mitigating tool damage to make micromilling systems more reliable for batch production is the current research trend. In macroscale or conventional milling process a number of methods have been proposed for tool condition monitoring. Few of them have been applied for micromilling. This paper reviews different methods proposed and used in last two decades for monitoring the condition of micromilling tools. Applicability of tool condition monitoring methods used in conventional milling has been compared with the similar ones proposed for micromilling. Further, the challenges and opportunities on the applicability issues have been discussed. Soumen Mandal Copyright © 2014 Soumen Mandal. All rights reserved. Fuzzy Optimization Modeling Approach for QFD-Based New Product Design Wed, 09 Apr 2014 12:03:34 +0000 Quality function deployment (QFD) is a planning and problem-solving tool for translating customer requirements (CRs) into the engineering characteristics (ECs) of a product. Owing to the typical vagueness of functional relationships in a new product, product planning is becoming more difficult under uncertainties. To tackle the vagueness or imprecision in QFD, numerous scholars have applied the fuzzy set theory to QFD and proposed various fuzzy QFD models. In this study, a fuzzy linear programming model is developed to determine the optimal level of ECs, where the objective function is the overall customer satisfaction and the cost constraint is fuzzified. Finally, we use a software product design as a numerical example, which demonstrates that the proposed methodology can help the QFD team realize the overall customer satisfaction of new products catching up with or exceeding the competitors in the target market. Zhihui Yang and Yizeng Chen Copyright © 2014 Zhihui Yang and Yizeng Chen. All rights reserved. A Makespan Optimization Scheme for NP-Hard Gari Processing Job Scheduling Using Improved Genetic Algorithm Sun, 06 Apr 2014 13:45:22 +0000 An optimization scheme for minimizing makespan of Gari processing jobs using improved initial population Genetic Algorithm (GA) is proposed. GA with initial population improved by using job sequencing and dispatching rules of First Come First Served (FCFS), Shortest Processing Time (SPT), Longest Processing Time (LPT), and Modified Johnson’s Algorithm for -machines in order to obtain better schedules than is affordable by GA with freely generated initial population and by individual traditional sequencing and dispatching rules was used. The traditional GA crossover and mutation operators as well as a custom-made remedial operator were used together with a hybrid of elitism and roulette wheel algorithms in the selection process based on job completion times. A test problem of 20 jobs with specified job processing and arrival times was simulated through the integral 5-process Gari production routine using the sequencing and dispatching rules, GA with freely generated initial population, and the improved GA. Comparisons based on performance measures such as optimal makespan, mean makespan, execution time, and solution improvement rate established the superiority of the improved initial population GA over the traditional sequencing and dispatching rules and freely generated initial population GA. Adeyanju Sosimi, Folorunso Oladimeji Ogunwolu, and Taoreed Adegbola Copyright © 2014 Adeyanju Sosimi et al. All rights reserved. Simulation on Bidding Strategy at Day-Ahead Market Sun, 09 Feb 2014 12:16:45 +0000 In an electric power day-ahead market, market prices are not always cleared at marginal cost caused by the strategic bidding of generators. This paper presents the results of day-ahead market simulation by using a simple three-generation-companies’ model for the case of demand with price sensitivity and analysis of the profits depending upon bidding strategies. The results show that, without a demand response, generation companies with diverse generation can increase their profit by strategic bidding. Moreover, under this condition, even if the demand response is made sensitive, these characteristics do not change. It is clarified that one of these factors is the operating constraint of power generators. If the generation company’s low-cost power generators decrease, the company’s profit monotonically decreases as the speculated capacity increases. However, realizing this case requires an unreal demand response and many small companies without diverse generation. Unless the conditions above are satisfied, the wholesale power transactions only through a day-ahead market without price-sensitive demand mechanisms would create a sellers' market, where the sellers can easily manipulate the price. Kazunori Sawai and Tetsuo Sasaki Copyright © 2014 Kazunori Sawai and Tetsuo Sasaki. All rights reserved.