Norzima Zulkifli

A Mathematical Model for the Industrial Hazardous Waste Location-Routing Problem

Technology progress is a cause of industrial hazardous wastes increasing in the whole world . Management of hazardous waste is a significant issue due to the imposed risk on environment and human life. This risk can be a result of location of undesirable facilities and also routing hazardous waste. In this paper a biobjective mixed integer programing model for location-routing industrial hazardous waste with two objectives is developed. First objective is total cost minimization including transportation cost, operation cost, initial investment cost, and cost saving from selling recycled waste. Second objective is minimization of transportation risk. Risk of population exposure within bandwidth along route is used to measure transportation risk. This model can help decision makers to locate treatment, recycling, and disposal centers simultaneously and also to route waste between these facilities considering risk and cost criteria. The results of the solved problem prove conflict between two objectives. Hence, it is possible to decrease the cost value by marginally increasing the transportation risk value and vice versa. A weighted sum method is utilized to combine two objectives function into one objective function. To solve the problem GAMS software with CPLEX solver is used. The problem is applied in Markazi province in Iran.

Reviewing the Literature of Inventory Models under Trade Credit Contact

In the classical inventory models, it was assumed that the buyer pays for the purchased items as they are received from the seller. In practice, however, the seller allows the buyer to settle the account with a delay period. Such a contract has attracted the attention of many researchers and practitioners in recent years. Thus, this paper addresses the researches with delay in payment and presents pertinent information about developments and extensions of such models to provide an up-to-date review of the studies conducted since 1973 and assist in developing the future researches.

The Impact of Information System-Enabled Supply Chain Process Integration on Business Performance: A Resource-Based Analysis

This paper seeks to develop and test a model to examine the relationships between, technical aspects of IS resources (IS alignment, IS resources technical quality, IS advancement), supply chain process integration, and firm performance. A questionnaire-based survey was conducted to collect data from 227 supply chain, logistics, or procurement/purchasing managers of leading manufacturing and retail organizations. Drawing on resources-based view of the firm, and through extending the concept of process integration in supply network, as well as broadening the scope of role of IS resources in relation to process integration and performance gain from the focal firm to the entire supply chain, we found that supply chain process integration is an important multidimensional intermediate organizational capability through which the value of IS resources for supply chain management can be materialized. This capability serves as a catalyst in transforming the value of technical aspects of IS resources into higher performance gain for a firm. Thus, the importance of formation of all dimensions of this capability across supply network should be realized. Moreover, the result suggests that the technical aspects of IS resources need to be jointly developed by supply partners to effectively form supply chain capabilities.

A Multiobjective Optimization Model in Automotive Supply Chain Networks

In the new decade, green investment decisions are attracting more interest in design supply chains due to the hidden economic benefits and environmental legislative barriers. In this paper, a supply chain network design problem with both economic and environmental concerns is presented. Therefore, a multiobjective optimization model that captures the trade-off between the total logistics cost and CO2 emissions is proposed. With regard to the complexity of logistic networks, a new multiobjective swarm intelligence algorithm known as a multiobjective Gravitational search algorithm (MOGSA) has been implemented for solving the proposed mathematical model. To evaluate the effectiveness of the model, a comprehensive set of numerical experiments is explained. The results obtained show that the proposed model can be applied as an effective tool in strategic planning for optimizing cost and CO2 emissions in an environmentally friendly automotive supply chain.

Adoption of Mobile Commerce: The Impact of End User Satisfaction on System Acceptance

Although voluntary individual usage behavior of information system and technology is well studied in the literature, further theoretical development is needed to account for the specific characteristics of the mobile commerce. This study presents an extended technology acceptance and satisfaction model presented by Wixom and Todd (2005) that integrates technology acceptance and technology satisfaction into unified model to investigate what determines user mobile commerce acceptance and usage. The contributions of this paper are to extend and adapt the user satisfaction and technology acceptance model in an empirical study of 503 mobile commerce users, shedding light on the significance and relative importance of specific acceptance and satisfaction factors. This study validates the user satisfaction and technology acceptance model in business to customer mobile commerce context. The implication of this study to both researchers and practitioners is discussed.

Integration of Lot Sizing and Flow Shop Scheduling with Lot Streaming

In manufacturing industries, production planning and scheduling strategy usually flow in a hierarchical direction. In this direction, the production planning problem is solved first; then the scheduling problem is solved to meet the production targets. This often generates an infeasible production plan because of not considering the details of scheduling. Therefore, it is necessary to develop models that can integrate production planning and scheduling. For manufacturing companies that have identical units of single products and are often grouped in production batches (lots), lot streaming can be used as a scheduling technique. However, there has been no model to integrate production planning (lot sizing) and scheduling, using lot streaming technique which can accelerate production. The main objective of this research is to develop mixedinteger mathematical models for integration of lot sizing and flowshop lot streaming problems such as variable sublots, consistent and equal sublots, scheduling with learning effects and the possibility of preventive maintenance tasks. The objective of these mathematical models is minimization of total costs and also, five goals of problem can simultaneously be solved, namely: determining the sequence among sublots, optimal number of sublots for each lot, size of each lot, inventory levels and size of individual sublots. The second objective of this research is to propose a solution procedure for problems when data are fuzzy. Finally, the third research objective is to validate the proposed model through a case study. Three software are used to extract the results of mathematical models and validate the solution procedure. The name of these software are: LINGO, MINITAB and MATLAB. In this research, the author proposes the first mixed-integer mathematical models for integration of lot sizing and lot streaming problems. By these proposed models, not only sequencing and timing decisions of multiple products are calculated but also lot size of each product, work-in-process and inventory levels of finished products are calculated when lots can be split into smaller sublots. To get the results of mathematical models, in three examples, 70 randomlygenerated problems are solved by LINGO solver. Moreover, a two-way ANOVA test as a statistical method is applied to validate the mathematical model, using four examples consisting sixteen problems, by MINITAB software. The NDM Company is used as a case study. The mathematical models are used to solve NDM company’s problems by LINGO solver. The results showed 32 percent (77.66 hours) reduction in makespan compared to non-integrated mathematical model. Validation of the proposed solution procedure is achieved by comparison of results with max-min method results,using Shahab Shishe company data. The results of using the proposed mathematical models in this research are first to reduce cost by using these proposed models. Secondly is greater marginal benefits were obtained by intermingled sublot cases than non-intermingled sublot cases. It is concluded that better makespans were obtained by intermingled sublot cases than non-intermingled sublot case.

Information requirements for sustainable consumption

Purpose - An increasingly important factor that influences purchasing decisions is that of environmental protection, particularly associated with climate change. This is particularly important as far as the purchase of consumer durables is concerned because of the energy that they consume; energy efficiency is one route towards minimizing environmental impact. Minimizing such impact is one factor towards achieving sustainability and therefore making possible sustainable development. This paper aims to address this issue. Design/methodology/approach - This paper shows that labeling is a crucial component of sustainable purchasing. It is based on literature and a review of current practice in various countries around the world. Findings - The central argument of this paper is that the desire to make sustainable purchasing decisions necessitates better information to make decisions according to this criterion. This in turn requires manufacturers to provide better information through their labeling. Social implications - The paper shows that better information enables more sustainable consumer purchasing decisions. Originality/value - This research extends knowledge of the components of sustainability and requirements for sustainable development, particularly as far as consumer purchasing decisions are concerned. It also has potentially important implications for manufacturers and also shows for them an important route towards achieving sustainable development for themselves and for the global economy.

Barriers to Advanced Manufacturing Technology in small-medium enterprises (SMEs) in Malaysia

Manufacturing companies strive to be competitive through the use of Advanced Manufacturing Technologies (AMT). AMT implementation is not simple with many barriers to its success, especially for smaller companies. These issues limit the access of small medium enterprises (SMEs) to the full benefits of the technology. This study is aimed to identify the barriers to successful AMT implementation in SMEs before improvement steps can be taken. A survey on the barriers was conducted on manufacturing SMEs in the Klang Valley region of Malaysia. From the results, a list of barriers was obtained and its severity ranked. The results showed that the lack of appropriate or proper training as the most severe barrier. The results may assist SMEs in understanding the state of Malaysian SMEs in implementing AMT and could serve as a guide to strategize solutions to overcome the barriers.

Robotic motion planning in unknown dynamic environments: Existing approaches and challenges

Path planning with obstacles avoidance in dynamic environments is a crucial issue in robotics. Numerous approaches have been suggested for the navigation of mobile robots with moving obstacles. In this paper, about 50 articles have been reviewed and briefly described to offer an outline of the research progress in motion planning of mobile robot approaches in dynamic environments for the last five years. The benefits and drawbacks of each article are also explained. These papers are classified based on their issues into ten groups which are: stability, efficiency, smooth path, run time, path length, accuracy, safety, future prediction (uncertainties), control, and less computation cost. Finally, some scope and challenging topics are presented based on the papers mentioned.

Developing a fuzzy linear programming model for locating recovery facility in a closed loop supply chain

In this research a closed loop supply chain is designed which incorporates reverse logistics and forward logistic system simultaneously. In the design of reverse logistic system, recovery options are embedded in traditional supply chain for treating returned products. The recovery system includes collection centres, remanufacturing plants and disposal centres. Since the product return is supply driven, there is an uncertainty about it. In the proposed configuration for closed loop supply chain, the optimised configuration for supply chain in terms of locating recovery plants is developed. Accordingly, a fuzzy mixed integer linear programming model develops to deal with the uncertainty of returning products by customers. A general-purpose solver (LINGO 8.0) and a Meta heuristic approach (genetics algorithm) are implemented to solve the proposed model. The answers are compared by defining indexes and then the optimal answer, configuration and variables are identified. This solution will suggest a new design of supply chain network in which waste of materials is minimised and the new raw materials are necessary only when the used products may not be recovered by recovery options.