| 1. |
- A Asif, Farazee M, 1980-, et al.
(författare)
-
Performance analysis of the closed loop supply chain
- 2012
-
Ingår i: Journal of Remanufacturing. - Germany : Springer Science and Business Media LLC. - 2210-4690. ; 2:4
-
Tidskriftsartikel (refereegranskat)abstract
- PurposeThe question of resource scarcity and emerging pressure of environmental legislations has brought a new challenge for the manufacturing industry. On the one hand, there is a huge population that demands a large quantity of commodities; on the other hand, these demands have to be met by minimum resources and pollution. Resource conservative manufacturing (ResCoM) is a proposed holistic concept to manage these challenges. The successful implementation of this concept requires cross functional collaboration among relevant fields, and among them, closed loop supply chain is an essential domain. The paper aims to highlight some misconceptions concerning the closed loop supply chain, to discuss different challenges, and in addition, to show how the proposed concept deals with those challenges through analysis of key performance indicators (KPI).MethodsThe work presented in this paper is mainly based on the literature review. The analysis of performance of the closed loop supply chain is done using system dynamics, and the Stella software has been used to do the simulation. Findings The results of the simulation depict that in ResCoM; the performance of the closed loop supply chain is much enhanced in terms of supply, demand, and other uncertainties involved. The results may particularly be interesting for industries involved in remanufacturing, researchers in the field of closed loop supply chain, and other relevant areas. Originality The paper presented a novel research concept called ResCoM which is supported by system dynamics models of the closed loop supply chain to demonstrate the behavior of KPI in the closed loop supply chain.
|
|
| 2. |
- Abdullah Asif, Farazee Mohammad, 1980-, et al.
(författare)
-
METHODS ANALYSIS OF REMANUFACTURING OPTIONS FOR REPEATED LIFECYCLE OF STARTERS AND ALTERNATORS
- 2010
-
Ingår i: 7th International DAAAM Baltic Conference"INDUSTRIAL ENGINEERING"22-24 April 2010, Tallinn, Estonia. - Estonia : Tallinn University of Technology. ; , s. 340-345
-
Konferensbidrag (refereegranskat)abstract
- The Design for Repeatedly Utilization (DFRU) is a proposed conceptto be used in the product realizationprocess to ensure optimum useable life (forinstance in terms of economy, resourceusage, environmental impact etc.) ofproducts or parts of products enablingmultiple lifecycle. In the DFRU approachproducts are restored as new like productsthrough remanufacturing processes. Theterm remanufacturing has been interpreteddifferently by different researchers and theindustries that are involved inremanufacturing business use differentapproaches to remanufacture theirproducts. In this paper the starter motorand alternator of automotives has beenused to demonstrate the novel concepts.The purpose of this paper is to expresswhat remanufacturing means in ourconcept, model their major lifecycleaspects and create a simulation modelfrom it. This is a preliminary work towardsdefining and specifying the processes,methods and design properties in DFRU.The work will be further extended to aholistic business model which can facilitateDFRU approach in an efficient way. Infuture the model will be developed andadopted to create new models for otherproducts appropriate for remanufacturingand eventually DFRU.
|
|
| 3. |
- Abdullah Asif, Farazee Mohammad, 1980-, et al.
(författare)
-
Minimizing Uncertainty Involved in Designing the Closed-loop Supply Network for Multiple-lifecycle of Products
- 2010
-
Ingår i: Annals Of DAAAM for 2010 & Proceedings of 21st DAAAM Symposium. - Zadar : DAAAM International. ; , s. 1055-1056
-
Konferensbidrag (refereegranskat)abstract
- To ensure multiple-lifecycle of products through remanufacturing intervention requires a well-functioning closed-loop supply network. Generally, the unpredictability of quantity, timing and quality (physical/functional) of the returned products and demand fluctuation of the remanufactured products are the main sources of uncertainty of closed-loop supply network. To some extent, efficient recollection strategies and separate distribution channels for remanufactured products can minimize the uncertainty. Nevertheless, efficient recollection does not necessarily close the loop if the recovered products do not enter into the main stream of the supply network. Beside, products that are distributed through separate channels create an open loop. Thus, the problem of uncertainty remains unsolved. The aim of this paper is to propose solutions to minimize the uncertainty involved in designing a well-functioning closed-loop supply network using the system dynamics principle and tool.
|
|
| 4. |
- Abdullah Asif, Farazee Mohammad, 1980-
(författare)
-
Resource Conservative Manufacturing : New Generation of Manufacturing
- 2011
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The question of resource scarcity and emerging pressure of environmentallegislations have put the manufacturing industry with a new challenge. On theone side, there is a huge population that demands a large quantity ofcommodities, on the other side, these demands have to be met by minimumresources and with permissible pollution that the earth’s ecosystem can handle.In this situation, technologic breakthrough that can offer alternative resourceshas become essential. Unfortunately, breakthroughs do not follow any rule ofthumb and while waiting for a miracle, the manufacturing industry has to findways to conserve resources. Within this research the anatomy of a large body ofknowledge has been performed to find the best available practices for resourceconservation. Critical review of the research revealed that none of the availablesolutions are compatible with the level of resource conservation desired by themanufacturing industry or by society. It has also been discovered that a largegap exists between the solutions perceived by the scientists and theapplicability of those solutions. Through careful evaluation of the state-of-theart,the research presented in this thesis introduced a solution of maximizingresource conservation i.e., material, energy and value added, as used inmanufacturing. The solutions emerged from the novel concept named asResource Conservative Manufacturing, which is built upon the concept ofMultiple Lifecycle of product. Unlike other research work, the researchdocumented in this thesis started with the identification of the problem andfrom which a ‘wish to do’ list was drawn. The seriousness of the problem andpotential of adopting the proposed concept has been justified with concreteinformation. A great number of arguments have been presented to show theexisting gaps in the research and from that, a set of solutions to conserveresources has been proposed. Finally, one of the prime hypotheses concerningclosed loop supply chain has been validated through the system dynamicsmodeling and simulation.
|
|
| 5. |
- Abdullah Asif, Farazee Mohammad, et al.
(författare)
-
System dynamics models for decision making in product multiple lifecycles
- 2015
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 101, s. 20-33
-
Tidskriftsartikel (refereegranskat)abstract
- The main drivers for adopting product multiple lifecycles are to gain ecological and economic advantages. However, in most of the cases it is not straight forward to estimate the potential ecological and economic gain that may result from adopting product multiple lifecycles. Even though many researchers have concluded that product multiple lifecycles result in gain, there are examples which indicate that the gain is often marginal or even none in many cases. The purpose of this research is to develop system dynamics models that can assist decision makers in assessing and analysing the potential gain of product multiple lifecycles considering the dynamics of material scarcity. The foundation of the research presented in this paper is laid based on literature review. System dynamics principles have been used for modelling and simulations have been done on Stella iThink platform. The data used in the models have been extracted from different reports published by World Steel Association and U.S. Geological Survey. Some of the data have been assumed based on expert estimation. The data on iron ore reserves, iron and steel productions and consumptions have been used in the models. This research presents the first system dynamics model for decision making in product multiple lifecycles which takes into consideration the dynamics of material scarcity. Physical unavailability and price of material are the two main factors that would drive product multiple lifecycles approach and more sustainable decisions can be made if it is done by taking holistic system approach over longer time horizon. For an enterprise it is perhaps not attractive to conserve a particular type of material through product multiple lifecycles approach which is naturally abundant but extremely important if the material becomes critical. An enterprise could through engineering, proper business model and marketing may increase the share of multiple lifecycle products which eventually would help the enterprise to reduce its dependency on critical materials.
|
|
| 6. |
- Adane, Tigist Fetene, et al.
(författare)
-
Application of system dynamics for analysis of performance of manufacturing systems
- 2019
-
Ingår i: Journal of manufacturing systems. - : Elsevier BV. - 0278-6125 .- 1878-6642. ; 53, s. 212-233
-
Forskningsöversikt (refereegranskat)abstract
- Machining of parts by using dedicated production systems has been, and continues to be, a viable manufacturing method. There are situations, however, where this type of system is not feasible due to changes in product type, customer demand, work-piece material, or design specification. From a competitive manufacturing environment, production system selection is a crucial issue for all component manufacturing companies. Improper selections could negatively affect the overall performance of a manufacturing system, for instance the productivity, as well as the cost and quality of manufactured components. In this paper, the application of system dynamics modelling and simulation of a complex manufacturing process is presented as a potential tool to investigate and analyse the performance of manufacturing system in response to disturbances in the system's inputs (e.g., volume of products). In order to investigate the model soundness, a case study applied to the manufacturing of an engine block will be examined. The model presented here has been developed based on current engine block production for the vehicle manufacturing industry. Such a model can assist manufacturing system selection-centered round the capacity to control machining system parameters -as a testable way to choose a machining strategy from pre-selected performance criteria. More specifically, the benefit of this research lies in the fact that it will enable companies to implement improved potential manufacturing system optimization that responds during unexpected demand fluctuations. In addition, it will help in understanding the complex interaction between the process and operational parameters of a manufacturing system and help identify those critical parameters, ones that can lead to an optimizing strategy in the manufacturing standards of engine block production.
|
|
| 7. |
- Adane, Tigist Fetene
(författare)
-
Manufacturing Dynamics and Performance Evaluation
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Manufacturing companies are striving to remain competitive in the market and maintain their economic growth and productivity. Uncertainties regarding the changes in product demand, workpiece material, product design, and technological advancement, have imposed pressure on manufacturing systems. Market uncertainties force manufacturing companies to be flexible and responsive in producing different parts, by adapting the existing system without the need for a substantial investment. The market is characterized by time variations in product quantities and varieties while manufacturing systems remain inherently fixed. To sustain competitive manufacturing, a company has to adopt to new production requirements and be responsive to market changes quickly. Conscious decisions have to be made for a system to respond to market fluctuations. In order to respond to the dynamic changes, there is a need for developing methodologies that analyse, evaluate and control performance of manufacturing system at the system and/or process levels.The primary focus of the thesis is to develop a novel generic framework for modelling and controlling manufacturing systems intending for improvement of the performance of manufacturing and make companies more competitive. The framework incorporates the complex interrelations between the process and system parameters, i.e., the dynamics of the system. Thus, provides a quantitative and qualitative analysis for performance evaluation and for optimizing performance of manufacturing system. The generic framework can further be adapted for studying specific manufacturing systems in discrete manufacturing. Three case studies are presented. The case studies are performed in an automotive company where the effect of various levels of control is investigated in manufacturing systems configured as transfer line or as a flexible manufacturing system.Two aspects of the dynamic nature of manufacturing system are investigated in this thesis: (1) The engineering nature of the system, i.e., the selection of appropriate process parameters to manufacture a product according to the design specification, and (2) The business nature of the system, i.e., the selection of system parameters with respect to the way the product is manufactured. At the process level, the parameters are controlled within the process capability limits to adapt to the changes of the system parameters in response to the market dynamics. At the system level, operational parameters are controlled to satisfy performance criteria.A case study for resource use analysis during primary processes has also been investigated and presented. The critical operations and the operations that have the highest energy consumptions and the potential for energy savings have been identified.The methodology developed for analysing the performance of the dynamic manufacturing system is based on a system dynamics modelling approach. Results obtained from different modelling approaches are presented and compared based on the selected performance metrics.
|
|
| 8. |
- Adane, Tigist Fetene, et al.
(författare)
-
Performance evaluation of machining strategy for engine-block manufacturing
- 2015
-
Ingår i: Performance evaluation of machining strategy for engine-block manufacturing. - 1895-7595 .- 2391-8071. ; 15:4, s. 81-102
-
Tidskriftsartikel (refereegranskat)abstract
- This paper will introduce a novel methodology for the performance evaluation of machining strategies of engine block manufacturing. The manufacturing of engine components is vital to the automotive and vehicle manufacturing industries. Machining is critical processes in the production of these parts. To survive and excel in the competitive manufacturing environment, companies need to improve as well as update their machining processes and evaluate the performance of their machining lines. Moreover, the lines and processes have to be robust in handling different sources of variation over time that include such examples as demand fluctuations, work-piece materials or even any changes in design specifications. A system dynamics modelling and simulation approach has been deployed to develop a methodology that captures how machining system parameters from the machining process are interacted with each other, how these connections drive performance and how new targets affect process and machine tool parameters through time. The developed model could provide an insight of how to select the crucial machining system parameters and to identify the effect of those parameters on the output of the system. In response to such an analysis, this paper provides (offers) a framework to examine machining strategies and has presented model that is useful as a decision support system for the evaluation and selection of machining strategies. Here a system dynamics methodology for modelling is applied to the milling operation and the model is based on an actual case study from the engine-block manufacturing industry.
|
|
| 9. |
- Adane, Tigist Fetene, et al.
(författare)
-
System dynamics analysis of energy usage : Case studies in automotive manufacturing
- 2012
-
Ingår i: SPS12 conference proceedings. ; , s. 1-9
-
Konferensbidrag (refereegranskat)abstract
- Our life is strongly linked with the usage of natural resources. Energy is a necessity in everyday life and is often generated using non-renewable natural resources which are finite. Energy consumption in manufacturing industry is increasing and the way it is consumed is not sustainable. There is great concern about minimizing consumption of energy in manufacturing industry to sustain the natural carrying capacity of the ecosystem. This is one of the challenges in today’s industrial world.In this paper two case studies have been carried out in crankshaft machining and cylinder head casting processes. The outcome of this research enables the company to identify potential avenues to optimize energy usage and offers a decision support tool.
|
|
| 10. |
- Adane, Tigist Fetene, et al.
(författare)
-
System dynamics analysis of energy usage: Case studies in automotive manufacturing
- 2014
-
Ingår i: International Journal of Manufacturing Research. - 1750-0591 .- 1750-0605. ; 9:2, s. 131-156
-
Tidskriftsartikel (refereegranskat)abstract
- Our life is strongly linked with the usage of natural resources. With increase in world population and welfare there is an increasing global demand for raw material. Energy is a necessity in everyday life and is often generated using non-renewable natural resources which are finite. Manufacturing is one of the largest energy and material resource consumers. There is great concern about minimising consumption of energy in manufacturing industry to sustain the natural carrying capacity of the ecosystem. This is one of the challenges in today’s industrial world. The paper presents the application of system dynamics theory for modelling and simulation of complex manufacturing processes. The simulations help to understand the intricate nature of the interrelation of process parameter and to make sound decision about minimising the energy losses. Two case studies are presented, one in cylinder head casting processes and the other in crankshaft machining. The developed models provide an insight into how to select critical operations and to identify the effect of various parameters on the energy consumption. Also, the models help to understand how changes of parameters over time affect the behaviour of energy changes. The outcome of this research enables the company to identify potential avenues to minimise energy usage and offers a decision support tool.
|
|
