Performance evaluation of a two-echelon inventory system with network lost sales

peer reviewe

Operative Planning with Exchangeable and Mandatory Tasks : Applications to Lot Size Planning and Transportation Planning

Lot-sizing problems of manufacturers and transportation planning problems of forwarders are presented and analyzed in this thesis. These problems represent crucial planning tasks in supply chain management. Due to high fluctuations and competitive markets, companies within supply chains use internal and external resources for the fulfillment of tasks. The thesis claims to contribute to the following topics: (1) introducing mandatory tasks for the DULR, IOTPP, CTPP, and CIOTPP as well as (2) presenting computational studies that demonstrate how much the costs of companies increase due to mandatory tasks. Mandatory tasks are tasks, which have to be fulfilled by appointed resources due to contractual obligations. A lack of research is identified in terms of this topic. It is usually assumed that a task can be fulfilled by any internal or external resources. The thesis describes how these planning tasks with mandatory tasks can be solved by using operations research. Therefore, existing mathematical models and solution approaches have to be extended. The thesis focuses on the determination of the impact of mandatory tasks based on computational studies

Dual sourcing : with arbitrary stochastic demand and stochastic lead times

Companies with high-performing supply chains enjoy essential competitive ad- vantages. However, supply chain management faces an environment of rising risk that endangers these competitive advantages. One of the reasons is to outsource parts of their business. This bears the risk of significantly increased lead times and lead time variability. It is the impact of lead time variability on inventory management that is the central aspect of this book. It describes a mathematical model for dual sourcing with two reorder points, shows the deviation between stochastic and deterministic calculations in a sensitivity analysis, and investigates different relaxations of a traditional dual-sourcing policy

The proposed comprehensive distribution system for the LO-MIS rotatable pool assets

A repairable item distribution system for the LO-MIX Program is developed in this thesis. The system is complete with recommended inventory locations, connecting transportation, and a method for monitoring the location and condition of the assets. In addition, a simulation model for the system is presented in flowchart format for future computer programming. This model is designed to provide an aid to system operating policy development and to allow testing of these policies prior to implementation. Transportation data for use by the model and in system planning is generated. This data is presented in distributions of the times experienced by air and truck shipments over the transportation legs of interest. The data is considered essential to system planning and policy testing.http://archive.org/details/proposedcomprehe00chriLieutenant Commander, United States NavyLieutenant, United States NavyApproved for public release; distribution is unlimited

Spare parts on demand using additive manufacturing : a simulation model for cost evaluation.

Little is known about the impact of additive manufacturing in the spare part supply chain. A few studies are available, but they focus on specific parts and their applications only. A general model, which can be adapted to different applications, is nonexistent. This dissertation proposes a decision making framework that enables an interested practitioner/manager to decide whether using additive manufacturing to make spare parts on demand is economical when compared to conventional warehousing strategy. The framework consists of two major components: a general discrete event simulation model and a process of designing a wide range of simulation scenarios. The goal of the dissertation is to help verify existing as well as gain new knowledge about operations of additive manufacturing and the cost implication in the spare parts supply chains. Particularly, the proposed model enables simulation based analysis with various strategies, setups, specific parts, machines and system operating parameters. Furthermore, the process related issues of interest are the influence of building speed, building space volume, material price, machine purchase price and cool down time. Strategy related issues are multi-machine and multi-material production strategies in several setups. Also simulation investigation of different spare part stock properties are executed and analyzed by using different part size distributions. This dissertation establishes fundamental understanding of the characteristics of the additive manufacturing system for spare part supply strategies. This model could directly help the decision-making processes in whether to adopt additive manufacturing technology, and also helps the evaluation of different additive manufacturing strategies when the technology is adopted. Both decisions (adoption and strategies) are made based on cost analysis for spare parts in a broader supply chain

Play Among Books

How does coding change the way we think about architecture? Miro Roman and his AI Alice_ch3n81 develop a playful scenario in which they propose coding as the new literacy of information. They convey knowledge in the form of a project model that links the fields of architecture and information through two interwoven narrative strands in an “infinite flow” of real books

A Polyhedral Study of Mixed 0-1 Set

We consider a variant of the well-known single node fixed charge network flow set with constant capacities. This set arises from the relaxation of more general mixed integer sets such as lot-sizing problems with multiple suppliers. We provide a complete polyhedral characterization of the convex hull of the given set