Given a picker-to-part warehouse having a simple rectilinear aisle arrangement with north-south storage aisles and east-west travel aisles (or "cross aisles"), this paper investigates the optimal placement of the cross aisles as a consequence of the probability mass function of the order pick points, as determined by the storage policy. That is, what placement of the cross aisles will result in a minimal expected path length for the picker? An analytical solutionprocedure is developed for the optimal placement of a single middle cross aisle for a given storage policy. A simplifying assumption is made as regards picker routing, but arbitrary non-random storage policies are considered. The solution procedure is generalized to a method for multiple cross aisles. Some example problems are solved and a simulation study is used to measure the impact of our simplifying assumptions.

This paper addresses the order-picking problem in a warehouse and establishes some criteria for the planning, design, and improvement of a warehouse layout to increase the order-picking efficiency. A simulation model has been developed to study the effect of warehouse layout on the order-picking throughput. Three major design elements of the warehouse layout are considered: crossing aisles, picking aisles orientation, and dock location. The system throughput is measured in terms of the traveling and waiting time of the picking vehicles. The results indicate that the order-picking efficiency can be substantially improved by orienting the picking aisles perpendicular to the dock, placing or locating the crossing aisles parallel to the dock and by locating the dock on the longitudinal side of the warehouse.

With increased globalization and offshore sourcing, global supply chain management is becoming an important issue for many businesses as it involves a company's worldwide interests and suppliers rather than simply a local or national orientation. The storage systems significantly affect the level of quality of products, the customer’s service level, and the global logistic cost. The mission of warehousing systems design, control and optimization is to effectively ship products in the right place, at the right time, and in the right quantity (i.e. in any configuration) without any damages or alterations, and minimizing costs. Warehousing in the Global Supply Chain presents and discusses a set of models, tools and real applications, including a few case studies rarely presented with a sufficient detail by other literature, to illustrate the main challenges in warehousing activities. This includes all warehouse operations (from receiving to shipping), problems and issues (e.g. storage allocation, assignment, layout, vehicle routing) for industrial and service systems as parts of global supply chains. Advanced and effective solving methods are also illustrated and the discussed case studies help the reader to quickly apply the proposed models and techniques/algorithms. Warehousing in the Global Supply Chain is useful to managers and practitioners of industry and service sectors for the determination and modeling of the critical issues concerning warehousing systems planning and design. It is a valuable source of information for engineering students, doctoral and post-doctoral students, and researchers of academic institutions who are searching for advanced modeling approaches and solving techniques to complex logistic decision making problems. Warehousing in the Global Supply Chain presents and discusses a set of models, tools and real applications, including a few case studies rarely presented with a sufficient detail by other literature, to illustrate the main challenges in warehousing activities. This includes all warehouse operations (from receiving to shipping), problems and issues (e.g. storage allocation, assignment, layout, vehicle routing) for industrial and service systems as parts of global supply chains. Advanced and effective solving methods are also illustrated and the discussed case studies help the reader to quickly apply the proposed models and techniques/algorithms. Warehousing in the Global Supply Chain is useful to managers and practitioners of industry and service sectors for the determination and modeling of the critical issues concerning warehousing systems planning and design. It is a valuable source of information for engineering students, doctoral and post-doctoral students, and researchers of academic institutions who are searching for advanced modeling approaches and solving techniques to complex logistic decision making problems.

This book constitutes the thoroughly refereed post-conference proceedings of the 4th International Symposium on Combinatorial Optimization, ISCO 2016, held in Vietri sul Mare, Italy, in May 2016. The 38 revised full papers presented in this book were carefully reviewed and selected from 98 submissions. They present original research on all aspects of combinatorial optimization, such as algorithms and complexity; mathematical programming; operations research; stochastic optimization; and graphs and combinatorics.