Monthly Archives: January 2014

How Many Pieces of Ice Cream Cake to Order?

coolerofcakes

The EOQ (economic order quantity) model celebrated its 100 birthday last year, being first published in February 1913 by Harris.  The EOQ model has held the test of time as it is still commonly used in practice and even has its own app (I guess it ages gracefully!).  To celebrate, the International Journal of Production Economics launched a special issue and I am happy to report that we are part of the party – our paper “A New Inventory Model for Cold Items that Considers Costs and Emissions” has been accepted.  Our model (an extension of the EOQ model) considers unit freezer capacities and analyzes inventory decisions based on both a financial and an environmental objective function.  This research was led by Ph.D. Student Ali Bozorgi, who is co-advised by Dima Nazzal (at Georgia Tech) and myself.  Using our model, we should be able to determine how many pieces of ice cream cake to order for the birthday party!  🙂

The paper specifics: 

A new inventory model for cold items that considers costs and emissions

Ali Bozorgi *, Jennifer A. Pazour* & Dima Nazzal**

*Department of Industrial Engineering and Management Systems, University of Central Florida, Orlando, FL, 32816, USA

**H. Milton Stewart School of Industrial and Systems Engineering
Georgia Institute of Technology, Atlanta, GA USA 30332

E-mails: ali.bozorgi@knights.ucf.edu; jennifer.pazour@ucf.edu; dima.nazzal@gatech.edu

to appear in the Special Issue Celebration of the 100th Anniversary of the EOQ Model for the International Journal of Production Economics (IJPE).

ABSTRACT: A new inventory model that considers both cost and emission functions is proposed for environments where temperature-controlled items need to be stored at a certain, non-ambient temperature and to do so modular temperature-control units are used.  Transportation unit capacity and storage unit capacity are considered, which results in non-linear, non-continuous cost and emissions functions. A set of exact algorithms are developed to find the optimal order quantity based on cost and emission function minimization, and the mathematical proof of the optimality of the solutions are presented.  Using a variety of parameter ratios, a set of experiments are run to show the effectiveness of the proposed model compared to the current models in the literature and to provide managerial insights into the cold item inventory problem. Optimum order quantity for cost function optimization and emission function optimization are compared against each other and the tradeoff between the functions is analyzed to provide insights.

Advertisements

2013 In Review

2013inreview

Being in my role as an assistant professor for a few semesters, 2013 was a year of me settling in and finding my groove.  Not only did I finally know where to find paper when the printer ran out, I also began to feel more comfortable in my role as a scholar and a teacher.  Here are my professional highlights of 2013 (in no particular order).

1.

I received two Congratulations-your-manuscript-has-been-accepted emails this year – both from IIE Transactions.

  • Ramtin, Faraz, and Pazour, Jennifer A., (to appear) “Analytical Models for an Automated Storage and Retrieval System with Multiple in-the-Aisle Pick Positions,” IIE Transactions. 
  • Roy, Debjit, Pazour, Jennifer A. and de Koster, Rene’, (to appear) “A Novel Approach for Designing Rental Vehicle Repositioning Strategies,” IIE Transactions. 

Both papers were started since I came to UCF and thus represent to me the beginning of my independent research agenda on logistics system design.  An exciting academic first was that one of the publications was with my Ph.D. student Faraz Ramtin.  I was also able to get a few more journal articles submitted and in the pipeline this year.

2.

Probably the most newsworthy event of 2013 was getting awarded a Young Investigator Award from the Office of Naval Research (I even received a congratulatory letter from the Orlando Mayor).  This 3-year grant focuses on using operations research models to quantify the impact that imperfect information has on sea-based logistics operations and to recommend how to design logistics operations in the face of imperfect information.  I have a great team of students working on the project and I have been impressed with the interest and involvement from ONR, the Marine Corps, and the Navy.  It is exciting research and I am learning a lot.

3.

“The Industry that Makes Supply Chains Work” is the tagline for the Material Handling Institute (MHI), which awarded me a “Start-Up” Grant in 2013.   From the beginning of my research career, material handling and logistics have been an integral part of my research portfolio.  I have continued research in analytical modeling of material handling systems as evident by the research being pursued by the Ph.D. students under my guidance. This include analysis of automated storage and retrievals systems with multiple pick points in the aisle, analysis of dense storage systems, and supply chain network design considering financial and environmental impacts.

4.

I am happy that my career is in the “education business” and that our product is knowledge, as well as empowerment and development of students.  Teaching is one of my favorite things about my job and I truly enjoy my time in the classroom.   In 2013 I taught a graduate course (EIN 6336 Production and Inventory Control) and an undergraduate course (EIN 4545 Industrial Engineering Applications in the Service Sector).  I must be doing something right, as I was awarded the most outstanding faculty member of 2012-2013 as voted on by the students of the UCF IEMS department.

5.

Finally, I want to say thank you to everyone that made 2013 successful. Whether it was an undergraduate researcher who jumped right in and started modeling cool operations research problems, or research collaborators that make the hazards of scheduling across three different time zones 10.5 hours apart totally worth it, or students in my classes who ask interesting questions – Thank you!