@inproceedings{555,
  abstract     = {{Although it is recommended to store goods in a warehouse based on the principle of first in first out, it is still unavoidable to use block storage of storing, for example, long andbulky goods. If the major advantage of block storage in area saving is themost important, the companyhas to accept the removal principle of last in first out or in other words, first in last out. The last goods to be stocked are the first goods to be removed and the first stocked goods are the last to be removed. There are some special observations in the block storage concerned in this paper. The first one is that the goods in the storage ordered by the customers can often not be removed directly from the storage without any stock movement. Theaim is to not only benefit fromthe high-density storage solution but also decrease the negative influence of block storage, especially when pre-stocked goods must be removed at first. The second observation is that during one concerned time period, forexample, one day, there may be several operations of put-away and several operations of order picking for shipment preparation. The third observation is that before goods are put away to storage, which goods to be removed are not always predictable. The preplanned removal dates are quite often unexpected changed. In this paper, scenarios with different dynamic properties and stochastic probabilities have been concerned and defined. Strategies for the three main stages of put-away, i.e. stacking, pre-marshalingand retrieval are defined and examined developed. Simulations have been conducted to examine the strategies based on different scenarios. The aimis to select the right strategy which may reduce the overall relocation operations. It is expected that the sum of blocks movement during put-away i.e. stacking, pre-marshaling, and block retrieval is optimally minimized.}},
  author       = {{Li, Li}},
  editor       = {{Villmer, Franz-Josef and Padoano, Elio}},
  isbn         = {{978-3-946856-03-0}},
  keywords     = {{Block storage, Put-away, Blocks relocation, Block retrieval, Order picking, First in last out, First in first out, Pre-marshalling}},
  location     = {{Lemgo}},
  number       = {{1}},
  pages        = {{101--112}},
  title        = {{{Put-Away and Retrieval Optimization Strategies towards Reduction of Blocks Relocations in a Block Storage}}},
  year         = {{2018}},
}

@inproceedings{599,
  abstract     = {{Order picking has long been identified as the most labor costly and intensively activity in warehouse management. The orders from the customers need to be fulfilled tightly and timely. In order to keep the required high service level, the warehouse has to increase the picking productivity under the constraints of limited capacity. This paper concerns a man-togoods order picking system, in which the order pickers have to drive with a pallet jack to the storage locations. Considering that the orders are mostly small orders which consist of less lines, it is efficient to combine severalsingle customer orders into one picking order. Under this circumstance, this paper intends to answer the question of how customer orders should be grouped into picking orders with the aim of minimizing the total travel length through the warehouse. Consequently the productivity of the order picking system can be improved. An optimization problem for order batching is introduced. The optimization method of order batching is then proposed. Based on the simulation of different scenarios of incoming orders, it can be concluded that the developed method is effective in improving the productivity of the concerned order picking system.
}},
  author       = {{Li, Li and Schulze, L.}},
  booktitle    = {{Production Engineering and Management}},
  editor       = {{Padoano, Elio and Villmer, Franz-Josef}},
  isbn         = {{978-3-941645-11-0}},
  keywords     = {{Order picking, man-to-goods, order batching, picking productivity, genetic algorithm}},
  location     = {{Trieste, Italy}},
  number       = {{1}},
  pages        = {{319--326}},
  title        = {{{Improving the Productivity of a Man-to-Goods Order Picking System through Optimization of Order Batching}}},
  year         = {{2015}},
}