Subramanian  Pazhani Author of Evaluating Organization Development
FEATURED AUTHOR

Subramanian Pazhani

Senior Operations Research Specialist
SAS Institute

Subramanian Pazhani is currently working as Sr. Operations Research Specialist with the Advanced Analytics and Optimization Services Group, SAS Institute, North Carolina. He holds a PhD in IE & OR from the Pennsylvania State University, University Park and MS in SCM from the IIT, Madras. His work has been published in prestigious journals such as Int. Journal of Production Economics, Computers & IE, Appl. Math. Modelling, Appl. Soft Computing, and Int. Journal of Operational Research.

Biography

Subramanian Pazhani is currently working as Senior Operations Research Specialist with the Advanced Analytics and Optimization Services Group, SAS Institute, Cary, North Carolina. He holds a PhD in Industrial Engineering & Operations Research from the Pennsylvania State University, University Park and MS in Supply Chain Management from the Indian Institute of Technology, Madras. His research areas include network design in closed loop supply chains, inventory optimization in supply chains, inventory routing problems, AGV scheduling in manufacturing and warehousing systems, dispatching and cycle time optimization in Semiconductor fabs. His work has been published in prestigious journals such as International Journal of Production Economics, Computers and Industrial Engineering, International Journal of Production Research, Applied Mathematical Modelling, Applied Soft Computing, and International Journal of Operational Research.

Areas of Research / Professional Expertise

    Network design in closed loop supply chains, Inventory optimization in supply chains, Inventory routing problems, AGV scheduling in manufacturing and warehousing systems, dispatching and cycle time optimization in Semiconductor fabs.

Personal Interests

    Movies, Cooking

Books

Featured Title
 Featured Title - Design and Analysis of Closed-Loop Supply Chain Networks - 1st Edition book cover

Articles

Multiple Criteria Decision Making in Supply Chain Management

A Bi-Criteria Model for Closed-Loop Supply Chain Network Design Incorporating Customer Behavior


Published: Mar 12, 2021 by Multiple Criteria Decision Making in Supply Chain Management
Authors: Subramanian Pazhani
Subjects: Engineering - Industrial & Manufacturing

Bi-Criteria Model for Closed-Loop Supply Chain Network Design Incorporating Customer Behavior

Computers & Industrial Engineering

Multi-Period Multi-Product Closed Loop Supply Chain Network Design: A Relaxation Approach


Published: Mar 12, 2021 by Computers & Industrial Engineering
Authors: Subramanian Pazhani, Abraham Mendoza, Ramkumar Nambirajan, TT Narendran, K Ganesh, Elias Olivares-Benitez
Subjects: Engineering - Industrial & Manufacturing

This paper develops decision-making models for two different CLSCs with multiple products over multiple periods. One of the networks has six levels, while the other has four levels, and they can be applied to products with different levels of complexity during inspection and remanufacturing operations. The supply chain networks are modeled as ILP. Taking advantage of the properties of the formulations, we propose an integer relaxation approach to obtain the optimal solution to ILP.

Wireless Networks

CAR: heuristics for the inventory routing problem


Published: Jan 11, 2020 by Wireless Networks
Authors: Ramkumar Nambirajan, Abraham Mendoza, Subramanian Pazhani, TT Narendran, K Ganesh
Subjects: Engineering - Industrial & Manufacturing

This paper addresses an IRP with a manufacturer that supplies a product using a fleet of vehicles to a set of warehouses over a defined time horizon. We develop a mixed integer linear program to determine the optimal allocation and the routing schedule for warehouses over the defined time horizon. To solve this problem, we propose a three-phase heuristic approach.

2018 29th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)

A bi-criteria mixed integer linear programming model for load balancing and chemical saving in wafer cleaning processes


Published: Apr 30, 2018 by 2018 29th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)
Authors: Subramanian Pazhani, Thomas Beeg, Kristopher Kowalczyk, Todd Dietrich
Subjects: Engineering - Industrial & Manufacturing

Wafer cleaning process in semiconductor fabrication comprises multiple steps at various stages of the product flow to remove particles and oxidize organic contaminants, using different chemicals. This paper focusses on front-end of the line wafer cleaning steps. We propose a bi-criteria mixed integer linear programming model to allocate daily demands to the equipment groups with the objectives of minimizing the maximum utilization and reducing chemical pre-dispenses.

Computers & Industrial Engineering

CARE: Heuristics for two-stage multi-product inventory routing problems with replenishments


Published: Jul 31, 2016 by Computers & Industrial Engineering
Authors: Ramkumar Nambirajan, Abraham Mendoza, Subramanian Pazhani, TT Narendran, K Ganesh
Subjects: Engineering - Industrial & Manufacturing

This paper studies an IRP involving multiple products from different suppliers, a central depot (CD) and a set of warehouses. We develop an ILP model to determine the optimal replenishments from suppliers to the CD as well as the routing schedules of vehicles from CD to the multiple warehouses over the defined time horizon. We propose an extended three-phase heuristic. In the heuristic, the replenishment schedules, from suppliers to the CD, is solved using a DP model.

International Journal of Production Economics

Finding optimal dwell points for automated guided vehicles in general guide-path layouts


Published: Mar 16, 2015 by International Journal of Production Economics
Authors: Ventura José, Pazhani Subramanian, Mendoza Abraham
Subjects: Engineering - Industrial & Manufacturing

In this paper, we address the problem of optimally locating dwell points for a given number of AGVs in a general guide-path layout. Based on an optimality property, we propose new mixed integer linear programming (MILP) formulations for three versions of the problem: (i) minimizing the mean response time in the system, (ii) minimizing the maximum response time in the system, and (iii) minimizing the maximum response time in the system considering time restrictions on vehicle availability.

Applied Mathematical Modelling

A Serial Inventory System with Supplier Selection and Order Quantity Allocation considering Transportation Costs


Published: Jan 01, 2015 by Applied Mathematical Modelling
Authors: S Pazhani, J Ventura, A Mendoza
Subjects: Engineering - Industrial & Manufacturing

Given the importance of incorporating transportation costs in inventory replenishment and supplier selection decisions, this article addresses the issue of supplier selection and order quantity allocation in a multi-stage serial supply chain system with multiple suppliers considering inventory replenishment, holding, and transportation costs simultaneously.

International Journal of Business Analytics (IJBAN)

Design of closed loop supply chain networks


Published: Jan 01, 2014 by International Journal of Business Analytics (IJBAN)
Authors: Subramanian Pazhani, A Ravi Ravindran
Subjects: Engineering - Industrial & Manufacturing

We consider a closed loop supply chain (CLSC) network with primarily commercial returns, which could be potentially recovered by light repair operations or by refurbishing. The annual estimate of commercial returns in the United States is in excess of $100 billion. This paper discusses the optimal design of a CLSC network. A MILP model is developed to determine the optimal locations of the facilities and the distribution of flows between facilities in the CLSC to maximize the total profit.

Applied Soft Computing

PRISM: PRIority based SiMulated annealing for a closed loop supply chain network design problem


Published: Feb 28, 2013 by Applied Soft Computing
Authors: P Subramanian, N Ramkumar, TT Narendran, K Ganesh
Subjects: Engineering - Industrial & Manufacturing

Concerns over environmental degradation, legislative requirements and growing needs of business have fueled the growth of CLSC. We consider a CLSC and address the issues of designing the network and of optimizing the distribution. Four variants of the problem are considered. The problem is modeled as an ILP. We develop a constructive heuristic to provide good initial solutions to a priority-based simulated annealing heuristic, to accelerate its convergence.

Journal of Industrial and Production Engineering

A bi-objective network design model for multi-period, multi-product closed-loop supply chain


Published: Jan 06, 2013 by Journal of Industrial and Production Engineering
Authors: Subramanian Pazhani, N Ramkumar, TT Narendran, K Ganesh
Subjects: Engineering - Industrial & Manufacturing

This paper addresses a bi-objective network design problem for multi-period, multi-product CLSC to minimize the total supply chain costs and to maximize the service efficiency of the warehouses and hybrid facilities. We develop a bi-objective mixed integer linear programming model to assist decisions in (1) location/operating decisions for warehouses, hybrid facilities and manufacturing facilities and (2) production and distribution of products between stages in the supply chain.

OPSEARCH

Mixed integer linear programming model for multi-commodity multi-depot inventory routing problem


Published: Jan 12, 2012 by OPSEARCH
Authors: N Ramkumar, P Subramanian, TT Narendran, K Ganesh
Subjects: Engineering - Industrial & Manufacturing

Multi-Commodity, Multi-Depot Inventory Routing Problem (MCMDIRP) is relevant to vendors who have to make decisions about timing of delivery, size of shipment and routing for multiple commodities from multiple manufacturing plants to warehouses in a VMI scenario. We propose a MILP for the MCMDIRP. The model is tested on a real life case study and a set of test data sets.

International Journal of Enterprise Network Management

A multi-criteria decision making model for outsourcing inbound logistics of an automotive industry using the AHP and TOPSIS


Published: Jan 01, 2009 by International Journal of Enterprise Network Management
Authors: N Ramkumar, P Subramanian, M Rajmohan
Subjects: Engineering - Industrial & Manufacturing

This paper focuses on the inbound logistics segment in the supply chain of automobile companies, which are known to be highly complex. We propose a model for selection of TPLs network with an objective to create a favourable environment for improving coordination and integration using analytic hierarchy process (AHP) and technique for order preference by similarity to ideal situation (TOPSIS) approach.