Operation of Production Systems

In the wake of recent global competition and pressures to reduce cycle-time, factories need to not only be well designed but should also be planned and scheduled for efficient production. Industrial production histories indicate that it is not uncommon for most parts spend about 80-90% of their time waiting in buffers/queues for machines or material handling equipment, and usually only a small 5-10% of their time on the shop-floor in actual machining. This is largely attributed to inefficient production planning and scheduling decisions. 

• Just In Time Production of Multi-Level Assemblies:  This research is has produced a class of finite capacity Just-In-Time production planning/scheduling methods for assembled products in a batch manufacturing environment (similar to MRP, but CAPACITATED!). Integrated lot-sizing and scheduling has been researched. Simultaneous scheduling of material handling transporters (such as Automatic Guided Vehicles or AGVs) and manufacturing equipment (such as machines and workcenters) has also been researched. The benefit of integration has been demonstrated.

• Performance Evaluation and Modeling:  Modeling and analysis of complex manufacturing systems and other discrete-event systems could be costly, both in computational and developmental terms.  Efficient gradient estimation methods for sensitivity analysis and optimization via simulation has been an area of interest.

• Production Planning, Management and Control of a production system subject to random events are challenging problems. A multi-layer hierarchical approach to tactical and aggregate production planning problems was developed, wherein the architecture is strongly dependent on the specific physical system, applicable controls and the complexity of the decision making problem at hand. This work is mostly summarized in two book chapters and several conference papers. 

• "Scheduling to Minimize Stringer Utilization," Outokumpu American Brass, Buffalo, NY with SPIR/TCIE; $32,381 (March 2003 – August 2003); Two students supported.
• "Knowledge Acquisition and Scheduling System Design," Carborundum Corporation, Amherst, NY with SPIR/TCIE; $88,299 (July 2000 – May 2001); Three students supported.
• "Operational Analysis and Facility Redesign Studies," Republic Drug Company, Buffalo, NY with SPIR/TCIE; $13,534 (May – July 1999); Two students supported.
• "Operational Analysis and Facility Design Studies," Imaging and Sensing Technology, Horseheads, NY with SPIR/TCIE; $17,042 (October – December 1998); Two students supported.
• "Operational Assessment: Facility Layout and Process Flow," Milward Alloys Inc., Lockport, NY with SPIR/TCIE; $10,239 (August – September 1998); One students supported.
• "Time Studies, Process Flow and Inventory Control," McKenica Corp., Buffalo, NY with SPIR/TCIE; $15,671 (July – August 1998); Two students supported.
• "Layout and Productivity Improvements at AVX Corporation," AVX Corp., Myrtle Beach, SC through TCIE; $4,409; co-PI L. Lin (June 1997).
• "Briquetting Productivity and Automation Enhancement," Manitoba Corp., Lancaster, NY through SPIR; $5,128 (December 1996 - January 1997). One student supported for one winter month.
• "Fuzzy Framework for Multi-Resource Multi-Project Management," RDF fund, SUNY at Buffalo, Department of Industrial Engineering; $2,250 (November 1994 - September 1995). One graduate student supported.
• "Operational Assessment at Premier Image," Premier Image, Buffalo, NY through TCIE; $1,095 (March 1994).
• "Optimal Facility Design and Cycle Time Reduction for Antenna Assembly," Investigator, $137,175 project funded by Westinghouse Corporation and MIPS, (Phase I : August 1991 - July 1992) (PIs Drs. G. Harhalakis and I. Minis at University of Maryland).
• "Optimal Facility Design and Cycle Time Reduction for Antenna Assembly," Investigator, $143,015 project funded by Westinghouse Corporation and MIPS, (Phase II : August 1992 - July 1993) (PIs Drs. G. Harhalakis and I. Minis at University of Maryland).

• Muhammad F. Anwar; Graduated 9/00. Dissertation title: "Integrated Transportation System and Workcenter Scheduling." Starting position: Assistant Professor, University of Memphis, TN.
  
• Ana Maria Sarmiento; Graduated 1/01. Dissertation title: "An Integrated Production-Logistics Approach to Partner-Chain Design in Agile Manufacturing." Recipient of the 1998 Doctoral Dissertation Proposal Award of Society of Logistics Engineers/International Society of Logistics. Starting Position: Manager I2 Technologies, Dallas TX.
  
• Luis Sanchez; Graduated 7/02. Dissertation title: "Location, Sizing and Production Allocation with Fixed and Mobile Manufacturing Facilities" Starting position: Director of Engineering and Science Department, ITESM Leon Campus, Mexico.
  
• Chaewon Bang; Graduated 1/03. Tentative dissertation title: "A Hybrid Integrated Approach for Process Planning and Shop-Floor Scheduling in Agile Manufacturing." Starting position: General Manager of CIM, Hyundai Information Technology, Co., Ltd., Seoul, S. Korea.
  
• Alfred Guiffrida; expected graduation 5/05. Tentative dissertation title: "A Cost-Based Model for Evaluating Supply Chain Performance."

• Muhammad F. Anwar; graduated 8/95. Thesis title: "Just-In-Time Production of Complex Assemblies with Finite Set-up Costs." Pursued a Ph.D. degree at SUNY-Buffalo.
  
• Vallish Shankar; graduated 7/96. Thesis title: "A Flexible Optimization Approach to Multi-Resource, Multi-Project Planning and Scheduling." Currently at Coopers and Lybrand, Chicago, IL.
  
• Sumiathangi Sriram; graduated 8/98. Thesis title: "A Hierarchical and Dynamic Distribution System for Agile Manufacturing based on Distributed Object Technology." Currently at I2 Technologies, Dallas, TX.
• Milind Mehere; graduated 8/98. Thesis title: "Integrated Distribution System Design with Warehouse Location and Logistics." (co-advised with Joyendu Bhadury). Currently at I2 Technologies, Cambridge, MA.
• Siddharth Batra; graduated 8/98. Thesis title: "Integrating Order Picking and Sortation in Warehouse Distribution Systems." Currently at 3Com, Santa Clara, CA.
  
• Ya-Ming Shiue; graduated 11/98. Thesis title: "A Decision Support Tool for Selecting and Sequencing Regularly Visited Customers in Courier Routing." (co-advised with Christopher Rump). Currently at Xerox, Rochester, NY.
• Osman Kazan; graduated 12/98. Thesis title: "New Lot-Sizing Formulations for Less Nervous Production Schedules." (co-advised with Christopher Rump). Currently at Dopkins and Co., Buffalo, NY.
  
• Kristen Wen; graduated 1/99. Thesis title: "Unit Cost Reduction through a Dynamic Staffing System for Unreliable Transfer Lines." Currently Manufacturing Engineer at GM Powertrain, Tonawanda, NY.
  
• Balaji Venkatesan; graduated 6/99. Thesis title: "An IT-OR Approach to Project Management in an Agile Manufacturing Environment." Currently at I2 Technologies, Cambridge, MA.
  
• Alfred Guiffrida; graduated 8/99. Thesis title: "A Cost-Based Model for Evaluating Vendor Delivery Performance." Currently pursuing a Ph.D. degree at University at Buffalo.
  
• Parag Kulkarni; graduated 8/99. Thesis title: "Effect of batch move size on Just-In-Time production of Multi-level Assemblies." Currently at Microstrategy, Vienna, VA.
  
• Amol Adgaonkar; graduated 10/99. Thesis title: "Multiperiod Newsvendor Model with Forecast Update;" (co-advised with Ram Akella). Currently at I2 Technologies, Dallas, TX.
  
• Amol Amritkar; graduated 12/99. Thesis title: "Impact of Heijunka (Level Scheduling) on Internal Supply Chain Management in JIT Manufacturing Environment." Currently at I2 Technologies, Dallas, TX.
  
• Sanjay Ramanujan; graduated 1/01. Thesis title: "Decision Support System for Integrated Assembly Plan Generation and Task Scheduling." Currently at ILOG, Mountainview, CA.
  
• Ashwin Warrier; graduated 8/01. Thesis title: "A Decision Support Tool for the Inventory Allocation and Vehicle Routing Problem." Currently at SCT Corp. (supply-chain consulting), Philadelphia, PA.
  
• Abhay Joshi; graduated 8/03. Thesis title: "Reactive Scheduling in Workflow Management Systems: A Branch-and-Price Approach." Currently pursuing PhD at University at Buffalo.
  
• Satyaki Ghoshdastidar; graduated 8/03. Thesis title: "Hierarchical Production Scheduling of Parallel Machines in the presence of Multiple Tooling and Resource Constraints and Sequence-Dependent Setup Times: Applications in Injection Molding Operations." Currently pursuing PhD at University at Buffalo.
  
• Sachin Mujawar; graduated 8/04. Thesis title: "Scheduling to Minimize Stringer Utilization for Continuous Annealing Operations." Starting position, Research Engineer at FM Global, Boston/Norwood, MA.

• Guiffrida, A.L. and Nagi, R. "Cost Characterizations of Supply Chain Delivery Performance," accepted to International Journal of Production Economics, January 2005. Download(PDF)
• Ghosh Dastidar, S. and Nagi, R. "Batch Splitting in an Assembly Scheduling Environment," accepted to International Journal of Production Economics, November 2004. Download(PDF)
• Ghosh Dastidar, S. and Nagi, R., "Scheduling Injection Molding Operations with Multiple Resource Constraints and Sequence Dependent Setup Times and Costs," Computers & Operations Research, 2005, Vol. 32(11), pp. 2987-3005. Download(PDF)
• Chauhan, S., Nagi, R. and Proth, J.-M. "Strategic Capacity Planning in Supply Chain Design for a New Market Opportunity," International Journal of Production Research, 2004, Vol. 42(11), pp. 2197 - 2206. Download(PDF)
• Agrawal, A., Minis, I. and Nagi, R., "Cycle Time Reduction by Improved MRP-based Production Planning," International Journal of Production Research, 2000, Vol. 38(18), pp. 4823-4841. Download(PDF)
• Kazan, O., Nagi, R. and Rump, C., "New Lot-Sizing Formulations for Less Nervous Production Schedules," Computers & Operations Research, 2000, Vol. 27(13), pp. 1325-1345. Download(PDF)
• Tung, L.-F., Lin, L. and Nagi, R., "Multiple-objective Scheduling for the Hierarchical Control of Flexible Manufacturing Cells," International Journal of Flexible Manufacturing Systems, 1999, Vol. 11(4), pp. 379-409. Download(PDF)
• Sarmiento, A.-M. and Nagi, R., "Recent Directions in Integrated Analysis of Manufacturing-Distribution Systems," IIE Transactions on Scheduling and Logistics, special issue on Manufacturing Logistics, 1999, Vol. 31(11), pp. 1061-1074. Download(PDF)
• Guiffrida, A.L. and Nagi, R., "Fuzzy Set Theory Applications in Production Management Research: A Literature Survey," Journal of Intelligent Manufacturing, 1998, Vol. 9(1), pp. 39-56. Download(PDF)
• Anwar, M.F. and Nagi, R., "Integrated Scheduling of Material Handling and Manufacturing Activities for Just-In-Time Production of Complex Assemblies," International Journal of Production Research, 1998, Vol. 36(3), pp. 653-681. Download(PDF)
• Shah, M., Lin, L. and Nagi, R., "A Production Order-driven AGV Control Model with Object-oriented Implementation," Computer Integrated Manufacturing Systems, 1997, Vol. 10(1), pp. 35-48. Download(PDF)
• Anwar, M.F. and Nagi, R., "Integrated Lot-sizing and Scheduling for Just-In-Time Production of Complex Assemblies with Finite Set-ups," International Journal of Production Research, 1997, Vol. 35(5), pp. 1447-1470. Download(PDF)
• Roach, A. and Nagi, R., "A Hybrid GA-SA Algorithm for Just-In-Time Scheduling of Multi-level Assemblies," Computers & Industrial Engineering, special issue on Genetic Algorithms in Industrial Engineering, 1996, Vol. 30(4), pp. 1047-1060.
• Agrawal, A., Harhalakis, G., Minis, I. and Nagi, R., "Just-In-Time Production of Large Assemblies," IIE Transactions on Scheduling and Logistics, 1996, Vol. 28, pp. 653-667.
• Fu, M.C., Hu, J.-Q. and Nagi, R., "Comparison of Gradient Estimation Techniques for Queues with Non-Identical Servers," Computers & Operations Research, 1995, Vol. 22(7), pp. 715-729.
• Fu, M.C., Hu, J.-Q. and Nagi, R., "Bias Properties of Infinitesimal Perturbation Analysis for Systems with Parallel Servers," Computers & Operations Research, 1991, Vol. 19(5), pp. 409-423.
• Nagi, R. and Proth, J.M., "Production Management Architecture," The Industrial Electronics Handbook, Editor in Chief: D. Irwin, pp. 653-662, CRC Press LLC, Florida, 1997. ISBN 0-8493-8343-9. (Refereed Book Chapter)
• Nagi, R. and Proth, J.M., "Hierarchical Production Management," Modern Manufacturing: Information Control and Technology, Editors: M. Zaremba and B.P. Prasad, pp. 132- 172, Springer-Verlag London, 1994. ISBN 0-387-19890-3. (Refereed Book Chapter)

• Sanchez, L.M. and Nagi, R., "Capacity Planning with Fixed and Mobile Facilities," 12th Industrial Engineering Research Conference, Portland OR, May 2003.
• Sanchez, L.M. and Nagi, R., "Location and Production Allocation of Fixed and Mobile Manufacturing Facilities," 11th Industrial Engineering Research Conference, Orlando FL, May 2002.
• Guiffrida, A. and Nagi, R., "A Cost-Based Model for Evaluating Supply Chain Performance," 29th International Conference on Computers and Industrial Engineering, Montreal Canada, November 2001, pp. 233-239.
• Anwar, M.F. and Nagi, R., "Integrated Conflict Free Routing of AGVs and Workcenter Scheduling in a Just-In-Time Production Environment," 6th Industrial Engineering Research Conference, Miami, FL, May 1997, pp. 216-221.
• Anwar, M.F. and Nagi, R., "Integration of Just-In-Time production and Material Handling in an Assembly Environment," 5th Industrial Engineering Research Conference, Minneapolis, MN, May 1996, pp. 281-286.
• Shankar, V. and Nagi, R., "A Flexible Optimization Approach for Multi-resource, Multi-project Planning and Scheduling," 5th Industrial Engineering Research Conference, Minneapolis, MN, May 1996, pp. 263-267.
• Harhalakis, G., Lin, C.P., Nagi, R. and Proth, J.M., "Hierarchical Decision Making in Computer Integrated Manufacturing Systems," Rensselear's Third International Conference on CIM, Troy, NY, May 20-22 1992.
• Harhalakis, G., Nagi, R., Proth, J.M. and Vernadat, F., "Design of Manufacturing Systems: A Bottom-up Approach Based on Petri Nets," Third International Conference on Data and Knowledge Systems for Manufacturing and Engineering, Lyon-France, March 1992.
• Harhalakis, G., Nagi, R. and Proth, J.M., "Hierarchical Modeling Approach for Production Planning," INCOM '92: 7th IFAC Symposium on Information Control Problems in Manufacturing Technology, Toronto, May 25-28 1992.

• Panikacherry, B.N. and Nagi, R., "An Integrated Framework For Distributed Scheduling And Logistics Management In Agile Manufacturing," 8th Industrial Engineering Research Conference, Phoenix AZ, May 1999.
• Venkatesan, B. and Nagi, R., "An IT-OR Approach to Project Management in an Agile Manufacturing Environment," 8th Industrial Engineering Research Conference, Phoenix AZ, May 1999.
• Bang, C. and Nagi, R., "An Integrated Framework for Process Planning and Shop Floor Scheduling in Agile Cellular Manufacturing," 8th Industrial Engineering Research Conference, Phoenix AZ, May 1999.
• Kazan, O., Nagi, R. and Rump, C., "New Lot-Sizing Formulations for Less Nervous Production Schedules," 8th Industrial Engineering Research Conference, Phoenix AZ, May 1999.
• Venkatesan, B. and Nagi, R., "Decision Support System for Logistical and Assembly Analysis of Rapidly Reconfigurable Complex Assemblies in an Agile Manufacturing Environment," Rensselaer’s International Conference on Agile, Intelligent, and Computer-Integrated Manufacturing, Troy, NY, October 1998.
  
• Anwar, M.F. and Nagi, R., "Integrated Scheduling and Logistics in an Assembly Environment," Rensselaer’s International Conference on Agile, Intelligent, and Computer-Integrated Manufacturing, Troy, NY, October 1998.
• Sriram, S.R. and Nagi, R., "A Hierarchical and Dynamic Distribution System for Agile Manufacturing based on Distributed Object Technology," Rensselaer’s International Conference on Agile, Intelligent, and Computer-Integrated Manufacturing, Troy, NY, October 1998.
  
• Sriram, S.R. and Nagi, R., "An Information Technology-Based Dynamic Distribution System for Agile Manufacturing," 7th Industrial Engineering Research Conference, Alberta Canada, May 1998.
• Sarmiento, A.-M. and Nagi, R., "Partnership Selection for Virtual Enterprises from Organizational Webs," 7th Industrial Engineering Research Conference, Alberta Canada, May 1998.
• Sarmiento, A.-M. and Nagi, R., "Analysis of a Two-Level Integrated Production-Distribution System," 1996 Conference on Agile and Intelligent Manufacturing Systems, Troy, NY, Oct. 1996.
  

• Joshi, A. and Nagi, R., "Reactive Scheduling in Workflow Management Systems: A Branch-and-Price Approach," invited (sponsored by Manufacturing, Services and Operations Management cluster) presentation in the INFORMS Fall 2003 Conference, Atlanta GA, October 2003.
• Anwar, M.F. and Nagi, R., "Lagrangean Relaxation Based Solution Approach for Integrated Material Handling System and Workcenter Scheduling," 10th Industrial Engineering Research Conference, Dallas TX, May 2001.
• Anwar, M.F., Batta, R. and Nagi, R., "Improved Integrated Scheduling & Logistics in an Assembly Environment using Concepts from Column Generation," invited presentation in the INFORMS Fall 2000 Conference, San Antonio, November 2000.
• Sarmiento, A.-M. and Nagi, R., "A Simulation Study of Manufacturing Supply Chains Cost under Demand Variations," presented in the INFORMS Fall 2000 Conference, San Antonio, November 2000.
• Sarmiento, A.-M. and Nagi, R., "A Modified Benders Approach as Lower Bound for Manufacturing Supply Chains Cost," presented in the INFORMS Fall 2000 Conference, San Antonio, November 2000.
• Anwar, M.F. and Nagi, R., "A Column Generation Approach for Integrated Scheduling and Logistics of Assemblies," invited presentation in the INFORMS Fall 1999 Conference, Philadelphia, November 1999.
• Mehere, M., Bhadury, J. and Nagi, R., "Integrated Distribution System Design with Warehouse Location & Logistics," presented in the INFORMS Spring 1999 Conference, Cincinnati, May 1999.
• Kazan, O., Nagi, R. and Rump, C., "New Lot-Sizing Formulations for Less Nervous Production Schedules," presented in the INFORMS Spring 1999 Conference, Cincinnati, May 1999.
• Sarmiento, A.-M. and Nagi, R., "An analytical tool to support the selection of partners from Organizational Webs in Agile Manufacturing," presented in the INFORMS Spring 1999 Conference, Cincinnati, May 1999.
• Sarmiento, A.-M. and Nagi, R., "Neural Network-based batch scheduling for an integrated agile production-distribution system," invited presentation in the INFORMS Fall 1998 Conference, Seattle, WA, October 1998.
• Anwar, M.F. and Nagi, R., "Integrated Scheduling of AGVs and Workcenters with the Consideration of Conflict Free Routing," invited presentation in the INFORMS Spring 1998 Conference, Montreal Canada, April 1998.