EFFECT OF VERTICAL TRANSSHIPMENT IN A DELIVERY SYSTEM By Pierre El Khoury.

EFFECT OF VERTICAL TRANSSHIPMENT IN A DELIVERY SYSTEM

By Pierre El Khoury

Outline

Some Background What a Delivery System is? What an Agents is? Definition of Transshipment Framework

Without Transshipment With Transshipment

Simulations What did we prove?

Where did the idea come from?

Delivery Systems Optimization

Review

Many Researchers focus on identifying a practical field which uses delivery, instead of tackling the delivery problem itself as a

concept...

Thus, there is no standardized scientific vocabulary to describe variations to the

delivery problem

Delivery in specific fields

Truck Delivery Problem (1)

(1) Jun Sawamoto, “Truck Delivery Scheduling System with a Mobile Communication Feature”, International Journal of Information Technology, August 2002.

Delivery in specific fields

Taxi Delivery Service (2) (3)

(2) Shih-Fen Cheng , Xin Qu , “A Service Choice Model for Optimizing Taxi Service Delivery”, School of Information Systems, Singapore Management University. (3) Der-Horng Lee, “A Taxi Dispatch System based on current demands and real-time traffic conditions”, 82nd Annual Meeting of the Transportation Research Board and consideration of publication in Transportation Research Record, November 12, 2002.

Delivery in specific fields

Shipping Services (4) (5)

(4) Ante Munitic, Slavko Simundic, Josko Dvornik, “System Dynamics Modelling of Material Flow of the Port Cargo System”, Split College of Maritime Studies, Faculty of Law Split, Croatia.(5) Mabel Chou, MiaoSong, Chung-Piaw Teo, “Inventory-Routing Problem in Sea Freight: Direct versus Transshipment Model”, July 30, 2003

What we did…

We did not move much away from what these researchers did…

We are thinking about our problem as a food delivery system, where orders are placed online, and many delivery boys

handle the delivery on a road mesh. In the system, we have multiple providers (restaurants), and multiple agents

(delivery boys)

But after we finished our study…

We gave our project a more general title, which describes more technically our

problem:

“Effect of using Transshipment as a vertical area division in a Delivery

System”

What is a Delivery System

A delivery system is widely referred to as a “Pickup and Delivery problem”,

according to the literature review we conducted… (6)(7)(8)(…)

(6) Snezana Mitrovic-Minic, Gilbert Laporte, “The Pickup and Delivery Problem with Time Windows and Transshipment”, INFOR Vol. 44, p. 217-227, Aug 2006.(7) Sophie N. Parragh Karl F. Doerner Richard F., “A survey on pickup and delivery problems”, Hartl Institut fur Betriebswirtschaftslehre, Universitat Wien Brunnerstr, Austria, April 16, 2008.(8) Quan Lu, Maged Dessouky, “An Exact Algorithm for the Multiple Vehicle Pickup and Delivery Problem”, University of Southern California, Department of Industrial and Systems Engineering, December 12, 2002.

Pickup location

Delivery Location

Delivery Networks

What are agents?

The means by which we process the delivery.

In our example, agents are Delivery Boys

Transshipment

Transshipment is the shipping of goods to intermediate locations before they are

delivered to their final destination

Transshipment

From a legal point of view, Transshipment is looked upon with caution, since it could be used for illegal activities (ranging from

smuggling to terrorism)

By transshipment, some people try to disguise the point of origin of their goods

from Customs officials (9)

(9) US Customs and Borders Protection, “TRANSSHIPMENT, TECHNICAL INFORMATION FOR PRE-ASSESSMENT SURVEY”, Focused Assessment Program Exhibit 5L, US Department of Homeland Security, October 2003.

Transshipment

Transshipment is widely used in delivery systems optimization (6)(12). It is also widely

used to optimize supply chain management (10)(11)(12)

(6) Snezana Mitrovic-Minic, Gilbert Laporte, “The Pickup and Delivery Problem with Time Windows and Transshipment”, INFOR Vol. 44, p. 217-227, Aug 2006.(10) Yale T. Herer, Michal Tzur, “The Dynamic Transshipment Problem”, Naval Research Logistics, Vol. 48, (2001)(11) Jing Shao, Harish Krishnan, S. Thomas McCormick, “Incentives for Transshipment in a Supply Chain with Decentralized Retailers”, September 25, 2009.(12) Rodolfo Dondo, Carlos A. Méndez, Jaime Cerdá, “The supply-chain pick-up and delivery problem with transshipments ”, INTEC (UNL-CONICET), Güemes 3450, 2500- Santa Fe, Argentina, 24 June 2009.

Transshipment here

In this project, we study the effect of transshipment at specific locations inside

the network and we compare to the performance of the delivery system

without transshipment.

Framework

Assumptions:

Cost of preparing the goods at the provider node is small compared to the time needed by any agent to reach this node.

Environment costs (road costs, or costs between nodes) do not change with time.

Two cases: Delivery system without transshipment and with Transshipment

Delivery with No Transshipment

What is A*?

Why A*, not Dijkstra?

A* is almost Dijkstra, with a heuristic

But in Dijkstra, each node has to be aware of the entire search space in order for the algorithm to operate. Therefore, every node has to know the exact costs between nodes in the network

A* is admissible and optimal(13)

Also, the time complexity of A* is better than Dijkstra since we are using a heuristic (14)

(13) Dechter, Rina, Judea Pearl, "Generalized best-first search strategies and the optimality of A*“, Journal of the ACM 32 (3): 505–536, (1985).(14) Russell S J, Norvig, P, “Artificial Intelligence: A Modern Approach”, Upper Saddle River, Prentice Hall, pp. 97–104, (2003).

Delivery with Transshipment

Simulations

Table1: 7*7 No Transshipment

Simulation on a 7*7 network 1 2 3 4 5 6 7 8 9 10 Total 2663

Total Time 281 263 256 267 268 254 283 246 291 254 Average 266.3

Table2: 3*3 No Transshipment

Simulation on a 3*3 network 1 2 3 4 5 6 7 8 9 10 Total 1037

Total Time 104 125 97 105 111 122 86 102 92 93 Average 103.7

Table 3: 7*7 Vertical Transshipment

Simulation on a 7*7 network 1 2 3 4 5 6 7 8 9 10 Total 3124

Total Time 345 308 312 283 305 307 303 311 331 319 Average 312.4

Table 4: 3*3 Vertical Transshipment

Simulation on a 3*3 network 1 2 3 4 5 6 7 8 9 10 Total 1236

Total Time 133 107 119 153 103 113 150 122 116 120 Average 123.6

What did we prove?

These simulations show that using two agents to process deliveries between two areas,

using vertical transshipment, is worse than using them without transshipment.

Therefore, splitting the environment into two distinct areas was not beneficial for the

system.

How can we improve?

Check for the effect of transshipment in larger networks

Check for the effect of transshipment with more agents

Modify the transshipment concept adopted, so that transshipment can occur all over the network under specific conditions

The End…