Kaan Katircioglu - Academia.edu (original) (raw)

Papers by Kaan Katircioglu

IBM Journal of Research and Development, 2007

Successful implementation of an inventory optimization solution requires significant effort and c... more Successful implementation of an inventory optimization solution requires significant effort and can pose certain risks to companies implementing such solutions. Depending on the complexity of the requirements, the solution may also involve a substantial IT investment. In this paper, we present a cost-effective solution for inventory optimization that can be useful for small and mediumsized businesses with limited IT budgets. This solution can be implemented on any application platform that is capable of processing basic SQLe (Structured Query Language) commands. The solution eliminates the need to purchase additional software and has a framework in which sales data in an Enterprise Resource Planning (ERP) system are accessed, demand statistics based on this data are generated along with other key parameters, and optimal inventory policies, such as those involving safety stocks and lot sizes, are calculated and reported.

We present a simulation-regression based method for obtaining inventory policies for a two-echelo... more We present a simulation-regression based method for obtaining inventory policies for a two-echelon distribution system with service level constraints. Our motivation comes from a wholesale distributor in the consumer products industry with thousands of products that have different cost, demand, and lead time characteristics. We need to obtain good inventory policies quickly so that supply chain managers can run and analyze multiple scenarios effectively in reasonable amount of time. While simulation-based optimization approaches can be used, the time required to solve the inventory problem for a large number of products is prohibitive. On the other hand, available quick approximations are not guaranteed to provide satisfactory solutions. Our approach involves sampling the universe of products with different problem parameters, obtaining their optimal inventory policies via simulation-based optimization and then using regression methods to characterize the inventory policy for simila...

Supply Chain Management Review, Mar 1, 2003

2005 9th IFIP/IEEE International Symposium on Integrated Network Management, 2005. IM 2005., 2005

Report for early dissemination of its contents. In view of the transfer of copyright to the outsi... more Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g. , payment of royalties). Copies may be requested from IBM T.

This paper reports results of a study of inventory policies for Canadian Tire Pacific Associates ... more This paper reports results of a study of inventory policies for Canadian Tire Pacific Associates which operates 21 retail stores and a warehouse in the vicinty of Vancouver, British Columbia and maintains stock of over 30,000 products. We describe a periodic review, fixed lead time, singleproduct, single-facility model with random demand, lost sales and service constraints which we developed for potential application. The model utilizes empirical demand data to calculate the long run average cost of inventory and service level for a given (s,S) policy. We provide a search algorithm to quickly locate an optimal policy based on an updating scheme for the transition probability matrix of the underlying Markov chain, bounds on S and monotonicity assumptions on the cost and service level functions . We compare the computed policies to those currently in use on a test bed of 420 products and find that stores currently hold inventories which are 40% to 50% higher than those determined by o...

International Series in Operations Research & Management Science, 2011

... K. Katircioglu () IBM TJ Watson Research Center, Yorktown Heights, NY 10598, USA e-mail:kaan@... more ... K. Katircioglu () IBM TJ Watson Research Center, Yorktown Heights, NY 10598, USA e-mail:kaan@us.ibm.com ... More recently, there is some work on developing simple heuristics to solve multi-echelon problems including Shang and Song (2003) and Gallego and ¨Ozer (2005). ...

Production and Operations Management, 1999

This paper describes a periodic review, fixed lead time, single-product, single-facility model wi... more This paper describes a periodic review, fixed lead time, single-product, single-facility model with random demand, lost sales and service constraints that was developed for potential application at a Western Canadian retailer. The objective of this study was to determine optimal (s, S) policies for a large number of products and locations. To this end, we evaluate the long run average cost and service level for a fixed (s, S) policy and then used a search procedure to locate an optimal policy. The search procedure is based on an efficient updating scheme for the transition probability matrix of the underlying Markov chain, bounds on S and monotonicity assumptions on the cost and service level functions. A distinguishing feature of this model is that lead times are shorter than review periods so that the stationary analysis underlying computation of costs and service levels requires subtle analyses. We compared the computed policies to those currently in use on a test bed of 420 products and found that stores currently hold inventories that are 40% to 50% higher than those recommended by our model and estimate that implementing the proposed policies for the entire system would result in significant cost savings.

Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304), 1999

One of the most serious challenges in the semiconductor memory business is the rapid price declin... more One of the most serious challenges in the semiconductor memory business is the rapid price decline. We develop an allocation scheme that determines the die (chip) allocation among different memory products. The allocation takes into account available die capacity, customer service requirements, as well as price declines and demand distributions among different products

2013 IEEE International Conference on Services Computing, 2013

In Application Management Services (AMS), high resource utilization, effective resource planning ... more In Application Management Services (AMS), high resource utilization, effective resource planning and optimal assignment of service requests to resources are critical to success. Meeting these objectives requires a systematic and repeatable approach for determining the best way of measuring resource utilization, assessing workload and assigning service requests. In this paper, we present a two-step approach to help achieve the above objectives. We first measure the actual amount of effort that each resource spends on handling each service request (SR) based on a metadata model and a set of SR handling priority rules. Then, we proceed to measure resource utilization and assess SR assignment process based on the effort data calculated in step one.

2007 Winter Simulation Conference, 2007

In this paper, we present a framework for developing discrete-event simulation models for resourc... more In this paper, we present a framework for developing discrete-event simulation models for resource-intensive service businesses. The models simulate interactions of activities of demand planning of service engagements, supply planning of human resources, attrition of resources, termination of resources and execution of service orders to estimate business performance of resource-intensive service businesses. The models estimate serviceability, costs, revenue, profit and quality of service businesses. The models are also used in evaluating effectiveness of various resource management analytics and policies. The framework is aided by an information meta-model, which componentizes modeling objects of service businesses and allows effective integration of the components.

Proceedings of the 2010 Winter Simulation Conference, 2010

International Series in Operations Research & Management Science, 2003

Distribution Resource Planning (DRP) is a general framework for planning and managing inventory i... more Distribution Resource Planning (DRP) is a general framework for planning and managing inventory in distribution networks. The DRP framework can be applied to complex distribution networks with thousands of unique stock-keeping units and hundreds of stocking locations. It allows for non-stationary (e.g. seasonal) demand patterns and a wide variety of user-specified inventory control rules including all standard inventory policies such as (S, s) and fixed order quantity rules. A number of software implementations of DRP are commercially available and are widely used in industry. In this paper, we describe the logic underlying DRP and point out some of its limitations. The inner workings of DRP are not always familiar to the research/academic community. On the other hand, practitioners may be unaware of some of the shortfalls and limitations of the system. Our objective here is to bridge this gap. In particular, we show how the performance evaluation capability of DRP can be substantially enhanced by some simple analytical formulas, derived as approximations from base-stock and (S, s) control schemes.