Setting Cutoff Times for Picking Systems with Capacity Degradation

In the new landscape of e-commerce distribution, firms must offer increasingly aggressive delivery promises and then make good on them. These promises often take the form of a cutoff time, such that orders placed before the cutoff time receive premium service (next-day, same-day, etc.) and those placed afterward do not. Later cutoff times are stronger, of course, but the fulfillment system might not be able to process the order before the deadline. How late is too late? We develop a deterministic model to answer this and related questions when the order fulfillment system batches orders for efficient picking operations and therefore exhibits a phenomenon we call capacity degradation

The Human-Centric Warehouse

In theory and in practice, the objective of warehouse design has long been to meet operational requirements of throughput and service performance at minimum cost. A natural product of this “bottom line” approach has been warehouse buildings and operations ill-suited to the humans who spend their working lives interacting with them. We offer an explanation for the current approach, and argue that a new approach— a new paradigm —is needed. We then describe a comprehensive approach to warehouse design that includes human well-being as a primary goal

Data and models to build supply blocks for deploying Marine Corps units

Revisio

Comparison of Alternative Configurations for Dense Warehousing Systems

In heavily constrained environments requiring very high density storage, traditional aisle-based warehousing may not provide viable options. One feasible manifestation of high density storage systems is the ‘puzzle-based’ system, in which unit loads are moved through the system via manipulation of empty (escort) locations to retrieve desired items. Another option would be the use of movable concentric rings, with escorts being utilized to enable lateral movements of unit loads between the rings. In this paper, the authors present analytical results to compare retrieval time performance for these two types of high density storage systems for randomly demanded items under various assumptions regarding the initial placement of escorts. The paper concludes that the use of movable concentric rings results in significant improvement to retrieval time performance in comparison to rectangular, puzzle-based systems, and further concludes that additional research is warranted

The best shape for a crossdock

The article of record as published may be found at http://dx.doi.org/10.10.1287/trsc.1030.0077Within both retail distribution and less-than-truckload transportation networks crossdocks vary greatly in shape. Docks in the shape of an I, L, or T are most common, but unusual ones may be found, including those in the shape of a U, H, or E. Is there a best shape? We show that the answer depends on the size of the facility and on the pattern of freight flows inside. Our results suggest that many large crossdocks in practice suffer from poor design that increases labor costs on the dock.Office of Naval ResearchNational Science FoundationN00014-95-1-0380 (ONR)DMI-0008313 (NSF)N00014-00-WR-20244 (ONR

Plug-and-Work Material Handling Systems

One disadvantage of automated material handling systems is their relative Inflexibility: once racks are installed and conveyors are laid, making even mi-nor changes to a system can be cumbersome and expensive. However, recent progress in the capabilities and cost of basic system components, such as controllers, drives, and sensors, has made possible a new class of material handling systems having a much higher degree of flexibility. We propose underlying de- sign principles for such systems and describe several prototype plug-and-work systems, which feature decentralized control and ease of reconfiguration

ISTRAŢIVANJE POSEBNOSTI GOSTIJU HOTELA BAŠTINE – PRIMJER GRADA SPLITA : Diplomski rad

Glavni cilj ovog diplomskog rada je dati odgovor na pitanje postoji li razlika u obiljeţjima i stupnju zadovoljstva elementima ponude Splita izmeĎu gostiju hotela baštine i uobičajenih gostiju destinacije. Kako bi se dobio odgovor postavljene su dvije hipoteze. Prva hipoteza se dijeli na sedam pomoćnih hipoteza koje su se odnosile na obiljeţja gostiju/turista, a druga hipoteza je ispitivala stupanj zadovoljstva pojedinim elementima ponude grada Splita. Za istraţivanje se koristio anketni upitnik kojeg su ispunjavali gosti hotela baštine, nakon toga podaci su se usporeĎivali s već postojećim istraţivanjem provedenim 2016. godine na turistima grada Splita. Rezultati istraţivanja su pokazali kako se obje kategorije turista razlikuje po svim navedenim obiljeţjima, osim po stupnju obrazovanja. Gledajući zadovoljstvo elementima ponude destinacije, turisti hotela baštine su u prosjeku zadovoljniji od uobičajenih turista.The main objective of this thesis was to answer the question of whether there was are significant differences in characteristics and the degree of customer satisfaction- between the tourists residing in designated Heritage hotels versus other tourists that stayed in Split. In order to obtain an objective response, two varying hypotheses were set up. The first hypothesis, which was directly related to the characteristics of the Heritage hotel guests, was subdivided into seven auxiliary hypotheses. The second hypothesis was related to examining the degree of satisfaction with elements that Split has to offer as a tourist destination. A survey questionnaire was prepared and used in obtaining the required information. The results and data provided were then compared with previous existing data, conducted in 2016, on tourists who stayed in the City of Split. The results of the research have shown that both categories of guests differed significantly in almost all characteristics with the exception of their respective degree of education. Upon a review of the level of satisfaction, Heritage hotel guests reported an average higher satisfaction rating

A dynamic distribution model for combat logistics

New warfare doctrine for the U.S. Marine Corps emphasizes small, highly mobile forces supported from the sea, rather than from large, land based supply points. The goal of logistics planners is to support these forces with as little inventory on land as possible. We show how to configure the land based distribution system over time to support a given battle plan with minimum inventory. Logistics planners could use the model to support tactical or operational decision making

Wave Release Strategies to Improve Service in Order Fulfillment Systems

Naval Postgraduate School Acquisition Research Progra

Sea based logistics: Distribution problems for future global contingencies

Proceedings of the 1997 Winter Simulation Conference ed. S. Andradóttir, K. J. Healy, D. H. Withers, and B. L. NelsonEvolving doctrine in the U. S. Marine Corps emphasizes small, highly-mobile forces, supported from the sea rather than from large, land-based supply points. We introduce some emerging problems in sea based logistics, and show how simulation might be used to address them. We describe a simulation model of the o ff load of supplies to support a Marine Air-Ground Task Force, and show how to determine the number and allocation of di fferent material handling devices for such an operation