Development of a demanufacturing system modeling and simulation tool

This thesis develops a demanufacturing system modeling and simulation tool as an interface between simulation methods and demanufacturers. This tool can mimic the behavior of demanufacturing facility and obtain penetrable understanding of the system. By this modeling tool, one can intuitively analyze the behavior of a system and improve the operational efficiency. Detailed designs on the simulation tool including user interface, logic, and user view are presented in this thesis. The initial prototype version of the system modeling and simulation tool has been completed with fourteen modules in the developed template. Each object in the template refers to a specific demanufacturing activity and uses detailed simulation logic behind its design to perform that activity. The application to an electronic demanufacturing facility illustrates the usefulness of the interface to manage and improve the overall efficiency of facilities. This thesis also applies the simulation tool to a typical demanufacturing facility. Relevant system performance is analyzed. The comparison of different operational scenarios is made and the suggestion for better options of the system is discussed. This work is useful to assist designers in the design of efficient demanufacturing systems to tackle the environmental problems that may be caused by retired or faulty products

Energy and Carbon Dioxide Impacts from Lean Logistics and Retailing Systems: A Discrete-event Simulation Approach for the Consumer Goods Industry

abstract: Consumer goods supply chains have gradually incorporated lean manufacturing principles to identify and reduce non-value-added activities. Companies implementing lean practices have experienced improvements in cost, quality, and demand responsiveness. However certain elements of these practices, especially those related to transportation and distribution may have detrimental impact on the environment. This study asks: What impact do current best practices in lean logistics and retailing have on environmental performance? The research hypothesis of this dissertation establishes that lean distribution of durable and consumable goods can result in an increased amount of carbon dioxide emissions, leading to climate change and natural resource depletion impacts, while lean retailing operations can reduce carbon emissions. Distribution and retailing phases of the life cycle are characterized in a two-echelon supply chain discrete-event simulation modeled after current operations from leading organizations based in the U.S. Southwest. By conducting an overview of critical sustainability issues and their relationship with consumer products, it is possible to address the environmental implications of lean logistics and retailing operations. Provided the waste reduction nature from lean manufacturing, four lean best practices are examined in detail in order to formulate specific research propositions. These propositions are integrated into an experimental design linking annual carbon dioxide equivalent emissions to: (1) shipment frequency between supply chain partners, (2) proximity between decoupling point of products and final customers, (3) inventory turns at the warehousing level, and (4) degree of supplier integration. All propositions are tested through the use of the simulation model. Results confirmed the four research propositions. Furthermore, they suggest synergy between product shipment frequency among supply chain partners and product management due to lean retailing practices. In addition, the study confirms prior research speculations about the potential carbon intensity from transportation operations subject to lean principles.Dissertation/ThesisPh.D. Sustainability 201

A computer simulation of the palletizing system at Frito-Lay, Inc. in Topeka, Kansas

Call number: LD2668 .T4 1985 C37Master of Scienc

Some contribution in operations research

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Implementation of automated assembly

Research has shown that about 60 - 80% wealth producing activities is related to manufacturing in major industrial countries. Increased competition in industry has resulted in a greater emphasis on using automation to improve productivity and quality and also to reduce cost. Most of the manufacturing works such as machining, painting, storage, retrieval, inspection and transportation have changed to automation successfully, except assembly. Manual assembly is predominant over automatic assembly techniques due to inherent assembly problem and the fact that the assembly machines lack the innate intelligence of human operator and lack sufficient flexibility to changeover when product designs and market demands change. With the advent of flexible manufacturing systems, which involve very large capital costs and complex interactions. For the reduction the risk of the investment and analyze the system, simulation is a valuable tool in planning the systems and in analyzing their behavior, and get the best use of them. This thesis applies animation techniques to simulate an automatic assembly system. In chapter 1 to 9, we cover some of the fundamental concepts and principles of automatic assembly and simulation. Some manufacturers put the subject of part orientation first on their list of priorities; but design for assembly (DFA) techniques have proven extremely valuable in developing better assembly techniques and ultimately, better products. We discuss DFA in chapter 1, part feeding and orientation in chapter 2. Chapter 3, 4 and 5 are concerned with assembly process, machines and control system, respectively. Annual sales for industrial robots have been growing at the rate of about 25 percent per year in major industrial countries, we review the robot application in chapter 6. The cost of material handling is a significant portion of the total cost of production, material storage uses valuable space and consumes investment, we cover these two topics in chapter 7 and 8. Chapter 9 is concerned with simulation. In chapter 10, 11,12 and 13, we implement a software package IGRIP to build a model of an automatic assembly system and analyze the result

A study of implementation and evaluation techniques of advanced guided vehicle systems

Call number: LD2668 .T4 1985 R42Master of Scienc

A contribution to validating of simulation models in production and logistics

In this dissertation a new way of thinking in the validation of simulation model methods in production and logistics systems is presented. The focus is on finding the most important parameters for the validation of simulation models, the relationships between these parameters in the form of correlations which influence the complexity of the models, the required availability of data for these parameters, and the uncertainty which is largely dependent on data availability. Further, a short assessment is made of sequential bifurcation as a method for model validation in the context of finding important parameters, reducing complexity, and exploring uncertainties

Development of VR-simulator software for manufacturing systems as a decision making and simulation tool

Modern manufacturing is characterised by high levels of automation and integration, complex interactions among system elements, and high capital costs. Simulation and Virtual Reality technologies hold tremendous promise for reducing costs, improving quality, process data management, enhancing control over operations and shortening the time-to-market for manufactured goods. Unfortunately, these technologies still remains largely underutilised by industry today due to the requirement for a high standard of skills in programming and modelling methodologies. Visualisation has become a critical component of simulation technology in manufacturing applications. It provides the simulation practitioners with an environment to discuss and get a better understanding of the simulation model’s behaviour. Graphical presentation and animation can be a significant tool to communicate the outcome of simulation models for the non-technical audience. Decision makers often do not have the technical knowledge to understand the statistical results of a simulation model. But when the outcome can be expressed using animation, a better level of understanding becomes possible. This thesis presents a VR-Simulator software developed entirely by the author to overcome some of the limitations of simulation packages to allow users (who are not specialists in simulation and virtual reality techniques, or have no programming skills) to develop simulation and virtual models of manufacturing systems automatically without any need for excessive training on modelling techniques or programming. The users can interact with the generated models using voice commands and virtual reality devices (e.g. HMD). The VR-Simulator can be used as an operational décision-support tool to enable decision makers to model and analyse manufacturing systems

The responsive reply chain: the influence of the positioning of decoupling points

Manufacturing supply chains have been challenged by high competition, dynamic, and stochastic conditions. They have to be constantly responsive in today’s ever-changing manufacturing environment. The proper positioning of decoupling points for material flow and information flow has a significant potential for increasing responsiveness in a supply chain. Positioning the material decoupling point as close to the end consumer as possible whilst the information decoupling point is positioned upstream is the key to the industries’ ability to reduce lead time and enhance performance in the dynamic behaviour of the supply chain. [Continues.

A computer graphics approach to logistics strategy modelling

This thesis describes the development and application of a decision support system for logistics strategy modelling. The decision support system that is developed enables the modelling of logistics systems at a strategic level for any country or area in the world. The model runs on IBM PC or compatible computers under DOS (disk operating system). The decision support system uses colour graphics to represent the different physical functions of a logistics system. The graphics of the system is machine independent. The model displays on the screen the map of the area or country which is being considered for logistic planning. The decision support system is hybrid in term of algorithm. It employs optimisation for allocation. The customers are allocated by building a network path from customer to the source points taking into consideration all the production and throughput constraints on factories, distribution depots and transshipment points. The system uses computer graphic visually interactive heuristics to find the best possible location for distribution depots and transshipment points. In a one depot system it gives the optimum solution but where more than one depot is involved, the optimum solution is not guaranteed. The developed model is a cost-driven model. It represents all the logistics system costs in their proper form. Its solution very much depends on the relationship between all the costs. The locations of depots and transshipment points depend on the relationship between inbound and outbound transportation costs. The model has been validated on real world problems, some of which are described here. The advantages of such a decision support system for the formulation of a problem are discussed. Also discussed is the contribution of such an approach at the validation and solution presentation stages