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Mehmet Gumus
PhD Candidate Department of Management Sciences University of Waterloo Waterloo, Ontario N2L 3G1 Canada Ph: (519) 888 4567 ext. 2475 or ext. 4519 e-mail: mgumus(atsign)uwaterloo.ca |
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| *After an eight-month internship at Siemens AG in Germany and Turkey, I am back at the University of Waterloo to finish my Ph.D. studies* |
| Click for links | Internships | Sample Projects | Memberships | |||
| Computer
Skills |
Education |
PhD Candidate in Applied Operations Research, Management Sciences, University of Waterloo MASci, Management Sciences, University of Waterloo, 2001 BS, Industrial Engineering, METU, 1999 |
| Research Interests | - Production and Inventory Management in Supply Chains
- Supply Chain partnerships and their impacts in coordination
- Location-Ditribution Analysis
- Supply chain networks with cross-docks
- Purchasing and Materials Management
- Risk management in purchasing
- Supplier management (supplier selection, classification, and development)
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| Teaching | - Instructor,
Department of Management Sciences, University of Waterloo - Teaching Assistant, Department of Management
Sciences, University of Waterloo: - Student Assistant, Industrial Engineering Department,
METU |
| Publications & Papers |
- Gumus, M. and J.H. Bookbinder (2004), "Cross-Docking
and its Implications in Location-Distribution Systems", Journal of - Gumus, M., Bookbinder,
J.H., and E. Jewkes (2004), "A Comparison Study: Identifying the Best PArtnership for Your Supply - Gumus, M., Bookbinder, J.H. and E. Jewkes, "Calculating
the benefits of vendor managed inventory in a - Gumus, M., Bookbinder, J.H. and E. Jewkes, "MIP
analyses of replenishemnt partnerships in supply chains with a single
- Gumus, M., Bookbinder, J.H. and E. Jewkes, "An
analytical study to identify the complications of consignment inventory
- Gumus, M., "A quantitative model for assessing
suppliers' risks in purchasing", model for cross-docks", Paper in progress, Department of Management Sciences, University of Waterloo - Contributer
to "Location and distribution modeling under NAFTA" by A. Robinson
& J. Bookbinder (click for the abstract) |
| Conference Talks |
- "Calculating the benefits of vendor managed inventory in a manufacturer-retailer system", CORS Annual Meeting, Halifax/Canada, May 2005 - "Models for the Location of Cross-docks", INFORMS Annual Meeting, Denver/USA, October 2004 (the abstract) - "CI Policies in a Two-Echelon Supply Chain", MSOM Conference, Eindhoven/Netherlands, July 2004 (click for the abstract) - "A Comparison Study: Identifying the Best
Partnership for Your Supply Chain", 24th National OR/IE Conference,
Adana/Turkey, June 2004 - "Multi-echelon Inventory Planning for
a Serial System with Time-varying Demand", 4th Annual Graduate Student
Research -"Cross-docking and its implications in location-distribution
networks", CORS Annual Meeting, Toronto/Canada, May 2002 |
| Awards & Scholarships |
- President's Graduate Scholarship, University of Waterloo, 2005-2006 - Ontario Graduate Scholarship (OGS), Government of Ontario, 2005-2006 - Ontario Graduate Scholarship (OGS), Government of Ontario, 2004-2005 - Ontario Graduate Scholarship in Science and Technology (OGSST), Government of Ontario, 2002-2003 - Fraser Award for Graduate Student Research (Best Research Paper Award), Department of Management Sciencest, 2002 - Dean's Entrance Scholarship, University of Waterloo, 2001 - Graduate Student Entrance Scholarship, University of Waterloo, 1999 and 2001 - International Graduate Student Scholarship, University of Waterloo, 1999-2001 - Faculty of Engineering Scholarship, University of Waterloo, 2001 - El-Gabbani Merit Scholarship, Department of Management Sciences, 1999 - Success Scholarship, METU, 1995-1999 - Merit Scholarship, Turkish Prime Ministry, 1995-1999
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| Memberships | CORS - Canadian Operational
Research Society INFORMS -Institute for Operations Research and the Management Sciences WATMIMS - Research Center for Logistics and Manufacturing/ University of Waterloo (Associated Member) |
| Internships | - Siemens AG, Automation and Drives, Conrols and Distributers
International Procurement, Amberg, Germany (Headquarters), June-Sept. 2005
- coordinated RFQ's, set up online project controlling tool for global sourcing projects,
supported risk management and global sourcing activities world-wide (Czech Republic,
Turkey, India, China)
- Siemens AG, Automation and Drives
Global Procurement, Istanbul, Turkey, January-June 2005
- developped and implemented risk management in procurement, launched the project "continuous
improvement for suppliers, modeled procurement processes as a system, applied chance-risk
analysis for purchasing parts and materials, assisted in supplier management processes
- Silahsan AS, Production Planning Department
Kirikkale, Turkey, July-Aug 1998
- worked on forecasting, prodution scheduling, management information systems
- Princsan AS, Production Planning Department
Kirikkale, Turkey, June-Aug 1997
- first hands-on experience in general industrial engineering pactices, worked on
cost accounting
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| Sample Projects |
Bender's Decomposition for a single reservoir system For a twelve period time horizon, our objective is to investigate the ways of maximizing total ($) return on the water released. Deterministic and probabilistic nature of the problem is analyzed through various Bender's decomposition techniques. Results of the stochastic case are compared with those obtained from a Monte-Carlo Simulation. Supply Chain Cross-docking and its implications on location-distribution systems Two main components of logistics cost are transportation and inventory based. As a result, decreasing the transportation and inventory holding costs have attracted the greatest interest of the researchers in logistics field. Consolidating the items being shipped is one of the key issues to decrease the transportation cost. In an attempt to decrease the total cost of logistics, warehouses are replaced by cross-docking facilities Queuing models and discrete event simulation of material flow at Wolverine Ratcliffs Inc., Fergus Operations The end products of the company are sold to various companies located in Canada and USA where they are processed to form metal tubes. Recent observations in the factory showed that supply of the factory is less than its demand. The main concern of the company has been to increase the service level while keeping WIP inventory as low as possible Utilization rates, WIP inventory level, and throughput are the performance measures of the project. Location analysis at the Department of Management Sciences An optimization model was developed to find the optimum location of the copy room with respect to the demand of users (professors, graduate students and administrative staff) and location of these demand points. Production Planning and Inventory Control models for Yigit Battery Production scheduling of the work floor and effective inventory control policies are analyzed in an attempt to decrease the production and inventory related costs while keeping the service level as desired. Necessary MPS and MRP were designed. A database was built to keep the track of inventory levels in accordance with the designed MRP. Database design and decision support systems I ) A database system was successfully developed and implemented using MS Access. Decision support system was built to evaluate the system-wide performance, performance of the teachers, and the performance of students who were being prepared for board exams. II ) Design of a software to be used for airporter services (MS Access, SQL, VBA) Ergonomics ; Work & Time Study Ergonomic design and comparison of kitchens ; Time-study application in a (university) campus restaurant serving lunch and dinner.
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| Computer Skills |
- UNIX, and all
WINDOWS series (operating systems) - MS Office (Word, Excel, PowerPoint, Access) - Fortran, LISP and C++ , VBA (programming languages) - ARENA and AweSim (Simulation Software) - LINDO, LINGO, GAMS, CPLEX (Optimization Software) - SPSS (Statistical); Maple, Matlab (Mathematical) - SAP/ R3 |
| Links | - A
web-source about Industrial Engineering (including Production &
Operation Management, and Supply Chain Management & Logistics).
This is something I prepared couple of years ago, so it might need some
updates. |
| Abstracts | "Cross-Docking
and its Implications in Location-Distribution Systems", Journal
of
Business Logistics Cross-docking replaces traditional warehousing, enabling continuous flow of items without storage. Here we model location-distribution networks that include cross-docking facilities, to obrain the latter's impact on the supply chain. We formulate optimization models to minimize total cost in three-echelon networks, each model generalizing the preceeding one. The first includes a single manufacturer, one product type, and multiple customers. Cross-docks are to be located between origin and destinations. Besides solving optimally, a tool for quantitative analysis of direct-shipment decisions is developed. The second model considers mire that one product: We determine a cost effective sequence of items for indirect shipment (via cross-docks). Finally, in a network with multiple origins, optimal solutions are to be obtained for 40 medium-size and larger examples. "A Comparison Study: Identifying the Best PArtnership for Your Supply Chain", Proceedings of the 24th National OR/IE Conference, Adana/Turkey Consider a manufacturer that sells goods to a retailer. When each party makes independent decisions, one party's replenishment quantity may not be preferred by the other. Coordinated decision making, however, can help achieve system-wide optimality. It may reduce the need for inventories and lower the shipping costs, or enable improved utilization of resources at the manufacturer. Here, we present the charecteristics of various partnerships used for coordinated decision making. Through comparison, we show that system-wide cost savings can be realized with the right partnership. "Models for the Location of Cross-docks", INFORMS Annual Meeting, Denver/USA, October 2004 Cross-docking replaces traditional warehousing, enabling continuous flow of items without storage. We formulate several location models to decide the sites where CDs will be opened. These differ from typical warehouse- location models where facilities carry stock. Thus, opportunities to consolidate shipments of multiple products to one or several customers must be considered. "CI Policies in a Two-Echelon Supply Chain", MSOM Conference, Eindhoven/Netherlands, July 2004 In this presentation, we examine system-wide ordering and inventory holding costs for a vendor and supplier when they use consignment inventory for a single product with deterministic demand. With the use of consignment inventory (CI), the vendor owns items in inventory until they are sold. We show that when the customer makes replenishment decisions, system-wide costs can be highher when CI is used as compared to the case when the customer owns the inventory. We are also able to show that if the vendor makes replenishment decisions - as in Vendor Managed Inventory (VMI), the use of CI may result in lower system-wide costs. "Benefits of VMI Replenishment in a Two-Echelon System", CORS/INFORMS Joint International Meeting, May 2004 This paper examines the potential benefits of various Vendor Managed Inventory (VMI) agreements between two partners in a supply chain. We begin by outlining characteristics of VMI agreements, and then examine cost implications of changing which partner acts as the primary decision maker. We show that system-wide cost can be reduced by VMI, and that when such agreements require a shift of cost from one party to another, there is upper bound beyond which the system-wide cost is worse off. "Multi-echelon Inventory Planning for a Serial System with Time-varying Demand", 4th Annual Graduate Student Research Conference, University of Waterloo, April 2004 The competitive structure of market has recently enforced manufacturers to locate customers in the center of decision making. As a result, manufacturers are required to make more sensitive plans for production and stock-keeping. However, practitioners who deal with multi-stage systems of manufacturing or distribution have found this extremely difficult. The reasons stem from compliated interrelation between the stages, time-varying demand structures, and in some cases capacity limitations. Multi-stage systems of manufacturing or distribution are categorized, according to the flow of entities, serial, parallel, assembly or general (Billington et al., 1983). In such systems, there are two distinct issues to be addressed. First, each individual stage's capacity usage, when neecssary, should be considered. Second, a suitable lot-sizing technique need to be developed. In this study, we consider a certain manufacturing company that has an un-capacitated serial manufacturing system for a certain type of product. Using the echelon-inventory concept, we model, solve and compare optimal and heuristic approaches for minimizing inventory holding and setup costs. We show that a modified Silver&Meal method, which is easy to implement, generates near-optimal results. "Location and distribution modeling under NAFTA" NAFTA, the North American Free Trade Agreement between Canada, Mexico and United States, affords Canadian manufacturers better access to the Mexican economy, plus an alternate entry into the US. This research focuses on the movement of goods from the (labour intensive) Mexican operations to finishing plants across the US border, then through distribution centres to the final customer. The problem is to determine the optimal number and location of these finishing plants and DCs, each from a discrete set of alternatives, as well as specify the transportation mode employed on each arc and the corresponding flow. Total system costs are to be minimized. The transportation lead time between nodes requires that the model be analysed over a multi-period time horizon. We modelled this problem as a mixed-integer linear program with seventeen decision-variable sets (of which eight represent physical quantities, routes, or locations). Taking into account restrictions on capacity and system configuration, there are thirty-one constraint sets, with binary restrictions on the majority of variables. (An average problem size had between 600 to 2000 total decision variables, and between 700 and 4000 constraints.) Following a series of trials using sample data, the model was employed to investigate an industrial problem for Tectrol Inc., a manufacturer of power supplies. Results of these analyses provide some guidelines for effectively making facility location and distribution decisions under the provisions of NAFTA. |