Mechanical Engineering Commons^™

System Dynamics Approach In Inventory Management Of End-Of-Life Products In A Disassembly Line, Badr Johar, Surendra Gupta

Surendra M. Gupta

A major challenge original equipment manufacturers (OEMs) currently face is how to implement an effective reverse supply chain network that is both cost effective and efficient. The rapid increase in the end-of-life (EOL) products returns from end customers back to origin for recovery or proper disposal can be said one of the main reasons behind this interest. Thus, the purpose of this paper is to examine the relationship between all elements of inventory management in the disassembly context using the system dynamic modeling approach to analyze the inventory of disassembled parts. Analysis of different market scenarios is conducted. The system …

Dynamic Programming For Solving Disassembly-To-Order System Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Massoud, Surendra Gupta

Surendra M. Gupta

In this paper, we consider the disassembly-to-order (DTO) problem where a variety of returned end-of-life (EOL) products are disassembled in order to satisfy the demand for specified numbers of components. However, a lot of uncertainties exist in the disassembly process that further complicates the process. A DTO model has been developed that takes into consideration the different system uncertainties and variability. The DTO model was solved in multiple periods using dynamic programming (DP). The main objective was to determine optimal number of takeback EOL products in every period from each supplier to fulfill the demand of components while maximizing total …

Analysis Of A Kanban Controlled Disassembly Line With Sensor Embedded Products, Mehmet Ali Ilgin, Surendra M. Gupta

Surendra M. Gupta

The use of sensors in the detection of non-functional or missing components in a product before disassembling it is a promising approach to deal with the high level uncertainty associated with disassembly yield. This study presents a quantitative assessment of the impact of the sensor embedded products on the various performance measures of a kanban-controlled disassembly line. First, two separate design of experiments studies based on Orthogonal Arrays are carried out for the cases with and without sensor embedded products. Then, the results of paired-t tests comparing two cases based on different performance measures are presented.

Analysis Of Remanufacturing Policy With Consideration For Returned Products Quality, Kenichi Nakashima, Surendra M. Gupta

Surendra M. Gupta

This paper deals with the product acquisition control problem and considers returned product quality with two types of classes. The system includes the flow of the product returns from customers to the factory as well as the forward flow of the sales. We formulate the acquisition problem together with product quality and stochastic demand using the Markov decision process. A numerical example is given to show the implementation of the methodology.

The Effect Of Disassembly Process On Spare Parts Inventory Management In Post Product Life Cycle, Mehmet Ali Ilgin, Surendra M. Gupta

Surendra M. Gupta

Timely and cost-effective acquisition of spare parts at post product life cycle (PPLC) is a challenging task due to limited supply of new spare parts. The most commonly used solution to this problem is the placement of a final order in the beginning of PPLC. Another alternative is the use of disassembled parts from End of Life (EOL) products. In this study, we consider both alternatives at the same time. First, a detailed discrete event simulation (DES) model of a disassembly line is developed. Then, a Genetic Algorithm (GA) is integrated with the DES model for the optimization of Final …

Disassembly Of Sensor Embedded Products With Component Discriminating Demand, Mehmet Ali Ilgin, Surendra M. Gupta

Surendra M. Gupta

There is a high level uncertainty associated with disassembly yield due to existence of unfunctional and/or unneeded components in end of life products. Sensors embedded in critical components of a product can deal with this uncertainty by providing information on the type and condition of the components prior to disassembly. This study presents a quantitative assessment of the impact of sensor embedded products (SEPs) on the various performance measures of a kanban-controlled washing machine disassembly line. First, separate design of experiments studies based on orthogonal arrays are performed for the cases with and without SEPs. Then, the results of paired-t …

An Evaluation Of The Effect Of Sensor Embedded Products In Product Disassembly With Precedence Relationships, Mehmet Ilgin, Surendra Gupta

Surendra M. Gupta

A promising solution approach to deal with the uncertainty associated with disassembly yield is sensor embedded products (SEPs) which involve sensors implanted during the production process. This study presents a quantitative assessment of the impact of SEPs on the various performance measures of a kanban-controlled air conditioner disassembly line. First, separate design of experiments studies based on orthogonal arrays are carried out for the cases with and without SEPs. Then, the results of paired-t tests comparing two cases based on different performance measures are presented.

Linear Physical Programming For Solving The Multi-Criteria Disassembly-To-Order Problem Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Massoud, Surendra Gupta

Surendra M. Gupta

This paper focuses on the disassembly-to-order (DTO) problem. End-of-life (EOL) products are purchased from a number of suppliers in order to be disassembled into individual components to satisfy the demand for specified numbers of components. However, there are a lot of uncertainties that complicates the process. Previous work in the literature solved the DTO problem under multiple uncertainties and a single objective. Other models solved the multicriteria DTO problem with a single uncertainty. This paper develops a multi-criteria DTO model that takes into consideration multiple system uncertainties and solves it using Linear Physical Programming (LPP). The main objective was to …

Preemptive Goal Programming For Solving The Multi-Criteria Disassembly-To-Order Problem Under Stochastic Yields, Limited Supply, And Quantity Discount, Amre Z. Massoud, Surendra M. Gupta

Surendra M. Gupta

This paper considers the disassembly-to-order (DTO) problem where end-of-life (EOL) products are purchased for disassembly in order to satisfy the demand for specified numbers of components. Previous work in the literature solved the DTO problem with multiple uncertainties under a single objective while others solved the multi-criteria model with a single uncertainty. This paper develop a multi-criteria DTO model that would takes into consideration multiple system uncertainties and variability. The multi-criteria DTO model was solved using preemptive goal programming (PGP). The main objective was to determine optimal number of take-back EOL products in every period from each supplier in order …

Use Of Crystal Ball® To Predict Profitability Of A Reverse Supply Chain, Kishore K. Pochampally, Surendra M. Gupta, Tej S. Dhakar

Surendra M. Gupta

Traditionally, firms have been spending significant time and money in improving their forward supply chains while ignoring their potential reverse supply chains. However, in today’s competitive business environment, it is important that firms study the profitability and benefits of implementing a reverse supply chain while considering the uncertainties associated with the supply and composition of used products, disassembly time, recycling/remanufacturing time, and demand for recycled/remanufactured goods. In this paper, we demonstrate how a simulation software package, Crystal Ball®, can be used to help a firm predict whether investment in a reverse supply chain is profitable with respect to a given …

An Optimization Framework For Advanced Disassembly/Repair-To-Order Systems With Remaining-Life Adjustment, Onder Ondemir, Surendra Gupta

Surendra M. Gupta

Due to environmental awareness and realization of cost savings, disassembly-to-order (DTO) concept has become popular. One of the main obstacles to making optimal DTO decisions is the uncertainty involved in end-of-life products (EOLPs). This uncertainty is due to the lack of information about the condition and the quantity of EOLPs returned. This uncertainty is removed by advanced disassembly/repair-to-order systems utilizing sensors to monitor the products in their life-cycle. Sensor technology enables remaining life estimation, thus allows advanced DTO models to deal with sophisticated component and product demands with remaining life adjustment. This paper presents an optimization framework for advanced disassembly/repair-to-order …

A Genetic Algorithm Approach To End-Of-Life Disassembly Sequencing For Robotic Disassembly, Ahmed Elsayed, Elif Kongar, Surendra M. Gupta

Surendra M. Gupta

End-of-life (EOL) processing options include reuse, remanufacturing, recycling and proper disposal. In almost all cases, a certain level of disassembly may be required due to possible changes in the original product structure. Thus, finding an optimal or near optimal disassembly sequence is crucial to increasing the efficiency of the process. Disassembly operations are labor intensive, can be costly, have unique characteristics and cannot be considered as reverse of assembly operations. Since the complexity of determining the best disassembly sequence increases as the number of parts of the product grow, an efficient methodology is reuired for disassembly sequencing. In this paper, …

Cost-Benefit Analysis Of Sensor-Embedded Products Based Disassembly-To-Order System, Onder Ondemir, Surendra Gupta

Surendra M. Gupta

Due to environmental awareness and realization of cost savings, disassembly-to-order (DTO) concept has become popular. One of the main obstacles to making optimal DTO decisions is the uncertainty involved in end-of-life products (EOLPs). This uncertainty is due to the lack of information about the condition and the quantity of EOLPs returned. This uncertainty can be removed by sensors monitoring the products in their life-cycle. However, DTO systems utilizing these sensors will be more costly to establish and maintain. This paper presents economic justification of establishing advanced disassembly-to-order (DTO) systems in which sensor-embedded end-of-life products are disassembled in order to fulfill …

Improving Clinical Access And Continuity Through Physician Panel Redesign, Hari Balasubramanian, Ritesh Banerjee, Brian Denton, James Naessens, James Stahl

Hari Balasubramanian

BACKGROUND: Population growth, an aging population and the increasing prevalence of chronic disease are projected to increase demand for primary care services in the United States. OBJECTIVE: Using systems engineering methods, to re-design physician patient panels targeting optimal access and continuity of care. DESIGN: We use computer simulation methods to design physician panels and model a practice’s appointment system and capacity to provide clinical service. Baseline data were derived from a primary care group practice of 39 physicians with over 20,000 patients at the Mayo Clinic in Rochester, MN, for the years 2004–2006. Panel design specifically took into account panel …

Antimicrobial And Antioxidant Activities Of Essential Oil And Methanol Extract Of Jasminum Sambac From Djibouti, Fatou Abdoul-Latif, Prosper Edou, François Eba, Nabil Mohamed, Adwa Ali, Samatar Djama, Louis-Clément Obame, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The essential oil of jasminum sambac from Djibouti was subjected to screening for their possible antioxidant activity by two complementary test systems, namely DPPH free radical scavenging and beta-carotene-linoleic acid assays. Butylated hydroxytoluene (BHT) was used as positive control in both test systems. In the DPPH test system, the IC50 value of essential oil and methanol extract were respectively 7.43 and 2.30 μg/ml. In the beta-carotene-linoleic acid system, oxidation was effectively inhibited by Jasminum sambac, the RAA value of essential oil and methanol extract were respectively 96.6 and 93.9%. When compared to BHT, the essential oil and methanol extract had …

Writing Research Proposal: Literature Review And Database Search, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Maintenance Outsourcing Of A Multi-Process Manufacturing System With Multiple Contractors, Hakan Tarakci, Kwei Tang, Herb Moskowitz, Robert Plante

Hakan Tarakci

Consider a manufacturer with a manufacturing system that consists of multiple processes. The manufacturer’s revenue is determined by the minimum of the uptimes among the processes. The maintenance functions of the processes are outsourced to independent contractors so that each contractor is responsible only for one process. A performance-based incentive contract is offered to each contractor, consisting of an uptime target level and a bonus rate for exceeding the uptime target. Under the incentive contract, a contractor receives a bonus only when the achieved uptime exceeds the target level specified in the contract. We develop a model for jointly determining …

Incentive Maintenance Outsourcing Contracts For Channel Coordination And Improvement, Hakan Tarakci, Kwei Tang, Herb Moskowitz, Robert Plante

Hakan Tarakci

Consider a manufacturer who has a process with an increasing failure rate over time. In order to improve the process performance, the following two types of maintenance activity are outsourced to an external contractor: (i) preventive maintenance is performed periodically to improve the reliability of the process when the process is functional; and (ii) corrective maintenance is used to restore the process to a specified condition when it fails. We consider the use of incentive contracts to induce the contractor to select the maintenance policy that optimizes the total profit of the manufacturer and contractor. It is demonstrated that an …

Cluster Treatment Of Characteristic Roots, Ctcr, A Unique Methodology For The Complete Robustness Analysis Of Linear Time Invariant Multiple Time Delay Systems Against Delay Uncertainties, Rifat Sipahi

Rifat Sipahi

Today, many high-tech applications such as simultaneous metal machining, neural networks, internet data congestion, population dynamics, chemical processes, formation flight problems, etc., appear in the form of multiple time delay systems (MTDS ). Due to the presence of delays, the stability of the dynamics is under question and needs to be addressed. In the last four decades, the stability analysis of the general class, Linear Time Invariant MTDS (LTI-MTDS), has been one of the challenging problems of the systems and control community, which originates from the complex stability analysis due to their infinite dimensionality. For tackling this, a unique procedure …

Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The latest estimates of the FAO demonstrate the problems of the fight against hunger. These problems are manifested by the ever-increasing number of chronically undernourished people worldwide. Their numbers during the 1999-2001 period were estimated at about 840 million of which 798 million live in developing countries. Sub-Saharan Africa alone represented 198 million of those. In this part of Africa the prevalence of undernourishment ranges from 5-34%, causing growth retardation and insufficient weight gain among one third of the children under five years of age and resulting in a mortality of 5-15% among these children. Malnutrition resulting from undernourishment is …

Phd Thesis (Doctorat De Spécialité): Université De Ouagadougou, 1999. Dr. Mamoudou H. Dicko. Purification Et Propriétés Physico-Chimiques Des Enzymes De Curculigo Pilosa, Gladiolus Klattianus Et Boscia Senegalensis Catalysant L'Hydrolyse Des Polysaccharides (Amidon Et Béta-Glucanes), Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

The objective of this study was the research of novel and inexpensive sources of polysaccharides degrading enzymes such as amylases and glucanases from local plants in order to justify their biotechnological applications. The isolation of two l3-amylases and an endo-1,3-ß-D-glucanase was reached using common protein purification methods such as buffer extraction, ammonium sulfate fractionation, ionexchange and gel filtration chromatographies. The methods used were simple and easily reproducible, suggesting the possibilfty of large-scale production. ln the crude extract of Curculigo pilosa tuber, only ß-amylase was detected as starch degrading enzyme and its activity was approximately 282 Uig of fresh material. The …