Freight and Goods Movement

The Productivity of Multipurpose Seaport Terminals

Daganzo, Carlos F.
1990

This paper studies the peculiar queueing problem that arises at multipurpose port terminals serving two traffic types. Primary (liner ship) traffic obeys a schedule and has absolute priority on the use of the multipurpose facilities. Secondary (tramp) traffic, which arrives at random, can also be served elsewhere in the port. Secondary traffic is routed to the multipurpose berths only if doing so does not delay any primary ship. (The port knows a fair amount ahead of time the arrival times of these ships and the likely service times of both liners and tramps). The goal is to obtain simple...

Optimal Pricing Policies for Temporary Storage at Ports

de Castilho, Bernardo
Daganzo, Carlos F.
1991

Synchronizing Production and Transportation Schedules

Blumenfeld, Dennis E.
Burns, Lawrence D.
Daganzo, Carlos F.
1991

This paper examines whether it is cost-effective to synchronize production and transportation schedules on a production network. The network considered consists of one origin and many destinations. The origin produces parts that are shipped directly to each destination. Trade-offs between production set-up, freight transportation, and inventory costs on the network are analyzed, and total costs are compared for synchronized and independent schedules. The paper focuses on a simple production system, which can be modeled analytically and which allows the basic issues in synchronizing...

Storage Space vs Handling Work in Container Terminals

Taleb-Ibrahimi, Mounira
de Castilho, Bernardo
Daganzo, Carlos F.
1993

This paper describes handling and storage strategies for export containers at marine terminals and quantifies their performance according to the amount of space and number of handling moves they require. Identifying a “best” strategy is complicated because the optimization problem is combinatorial in nature—strategies are characterized, among other things, by the order in which future ship arrivals claim preferential space in the storage area. Given a certain traffic, the paper first examines the minimal storage space needed to implement the recommended strategies. This analysis may be of...

Handling Strategies for Import Containers at Marine Terminals

de Castillo, Bernardo
Daganzo, Carlos F.
1993

Many types of storage systems require goods to be stacked in a storage area. The amount of handling effort required to retrieve individual items from the stacks depends on stack heights and on the adopted storage strategy. The paper focuses on container import operations at marine terminals. It presents methods for measuring the amount of handling effort required when two basic strategies are adopted, one that tries to keep all stacks the same size and another than segregates containers according to arrival time. The strategies are compared in an idealized situation. The methods should be...

Handling Operations and the Lot Size Trade-off

Daganzo, Carlos F.
Newell, Gordon F.
1993

This paper presents a handling cost model for a warehouse that supplies one or more stores with a large number of items and examines operating strategies whose objective is to minimize the sum of handling, transportation and inventory costs. Decisions must be made regarding the frequency of shipments to the store(s) (i.e. the transportation schedule) and the specific items and lot sizes included in each shipment. The paper shows that, conditional on a transportation schedule, lot sizes for the different items (i.e. their delivery frequency consistent with the transportation schedule) can...

A Routing Model for Pickups and Deliveries: No Capacity Restrictions on the Secondary Items

Daganzo, Carlos F.
Hall, Randolph W.
1993

This paper examines a routing problem in which vehicles from a single depot cover a large area, where randomly located customers request pickup and delivery service. The paper assumes that each vehicle must serve its deliveries before it collects any pickups, that vehicles do not need to return to the depot between delivery and collection, and that each vehicle can serve at most C deliveries, but an unlimited number of pickups. This paper does not propose a detailed algorithm; rather, it discusses the pros and cons of various broad routing schemes, and quantifies their performance with...

The Variance of the Number of Customers in an Infinite-Server Queueing System with an Arbitrarily Correlated Arrival Process

Daganzo, Carlos F.
Diez-Roux, Esteban
1995

Motivated by a container storage problem at seaports, this paper examines the infinite-server queueing model with a (second order) stationary but arbitrarily correlated arrival process. It starts with a description of the application context, including an explanation of why non-standard inputs and service times arise in certain container storage problems. As further illustration, formulas characterizing the input and service processes for a particular situation are then presented and justified, together with the simple container accumulation variance formula that follows from the general...

Impact of Manufacturing Response Time on Retailer Inventory

Blumenfeld, Dennis E.
Daganzo, Carlos F.
Frick, Michael C.
Gonsalvez, David J.A.
1999

Retailers receiving items from a manufacturer carry inventory to meet customer demand. As items are sold, a retailer orders new items to replenish the inventory. Once an order is placed, there is a time taken for the items to be delivered to the retailer. This time is the manufacturing response time. It includes processing, production, and delivery times. These different components of time can result in response times that are long and uncertain. This paper develops a queueing model for analysing how manufacturing response time affects the inventory needed at retailers to meet demand. The...

Deferred Item and Vehicle Routing within Integrated Networks

Smilowitz, Karen R.
Atamtürk, Alper
Daganzo, Carlos F.
2003

This paper studies the possible integration of long-haul operations by transportation mode and service level (defined by guaranteed delivery time) for package delivery carriers. Specifically, we consider the allocation of deferred items to excess capacity on alternative modes in ways that allow all transportation modes to be utilized better. Model formulation and solution techniques are discussed. The solution techniques presented produce solutions for large-scale problem instances with up to 141 consolidation terminals and 17 breakbulk terminals. Allowing deferred items to travel by air...