Surendra M. Gupta
Sagar Kamarthi, Seamus M. McGovern
Date of Award
Doctor of Philosophy
Department or Academic Unit
College of Engineering, Department of Mechanical and Industrial Engineering
engineering, industrial engineering, disassembly, environmental consciousness, optimization, remanufacturing, reverse logistics, sensors
Recent technological advancements have energized the growth in electronics and thus endowed the customers with high quality yet inexpensive consumer goods. Availability of such products has caused a consumption revolution. In particular, used products are routinely discarded prematurely. In other words, products become obsolete or "old" in a much shorter time although they are still functional. This trend has led to tremendous depletion of virgin resources to satisfy the ever increasing demands of consumers.
Awareness on environmental problems has risen with the distressing increase in the use of virgin resources and has led to several legislations that extend manufacturers' responsibility beyond the point of sale. New legislations and public awareness have forced manufacturers to form a reverse flow originating from customers in order to eliminate negative impacts of their products on the environment when they reach their end-of-lives (EOL).
There are many advantages to EOL management such as reduction in the use of virgin resources, decrease in the use of landfills and cost savings stemming from the reuse of end-of-life products (EOLPs), disassembled components and recycled materials. In general, the management of EOLPs involves a set of operations viz. cleaning, disassembly, sorting, inspection, and recovery or disposal. There are several recovery options that can be selected. These options include product recovery, component recovery (cannibalization), and material recovery (recycling). Product recovery may take several forms such as remanufacturing, refurbishing, repairing and recycling. All recovery options involve disassembly operations up to a certain level. Disassembly is a labor intensive operation carried out to extract parts from EOLPs for several purposes including elimination of hazardous parts, reusable component recovery, component testing, and content inspection. Of all recovery operations, remanufacturing and disassembly are considered to be the most complex ones. This is mostly due to the lack of information about the quality and quantity of EOLPs and their components. When there is no information available on the components' quality status, comprehensive testing is needed to collect that. After testing, if an EOLP is found not suitable for remanufacturing, the time and resources spent on determining that are wasted, otherwise, necessary remanufacturing operations and spare parts are listed based on the testing results. EOLPs, however, do not show typical qualities since they originate from various sources where they are subjected to different working conditions. As a result, it is highly likely that each EOLP has its own quality condition exhibiting unique remanufacturing needs. Hence, finding the EOLPs with minimal recovery costs requires testing the whole EOLP inventory, which can be very expensive. However, emerging information technology devices, such as sensors and radio-frequency identification (RFID) tags, mitigate EOL recovery decision making by reducing or eliminating uncertainty.
Sensor embedded products (SEPs) are built with sensors implanted in them to monitor their critical components while they are in use. Sensors may be used in addition to the radio frequency identification (RFID) technology that has recently gained importance in closed loop supply chain operations, including reverse logistics, disassembly and remanufacturing, as a means of communication and data storage. Using the information collected by sensors, existence, types, conditions and remaining lives of components in an end-of-life product (EOLP) can be determined. Remaining useful life can be taken into account as a good measure of quality. Therefore, determination of remaining useful life allows decision makers to construct sophisticated recovery models that accommodate remaining life based demands and guarantee a minimum customer satisfaction level on recovered products while optimizing various system criteria.
In this dissertation, we investigate how sensors and RFID tags could be used to assist product recovery operations and propose an advanced remanufacturing-to-order and disassembly-to-order (ARTODTO) system for end-of-life sensor-embedded products (SEPs). Several mathematical models are developed for different recovery scenarios to determine how to process each and every end-of-life product on hand to meet the remaining life based product and component demands as well as recycled material demand while fulfilling various system criteria. Demands are met by disassembly, remanufacturing, and recycling operations. Outside component procurement option is used to eliminate the component and material backorders. Various scenarios are considered to illustrate the application of each proposed methodology. Together these scenarios form a body of knowledge that shed light on the importance of using SEPs in mitigating uncertainties and providing financial and environmental incentives in product recovery.
Ondemir, Onder, "End-of-life decision making models for sensorembeded products" (2012). Industrial Engineering Dissertations. Paper 13. http://hdl.handle.net/2047/d20002557
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