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Warehouse layouts, due to their influence on total warehousing costs, are of interest to the theory and practice of warehouse design. While the layout problem of unit-load storage area of conventional warehouses has quite a long history, the layout of conventional systems with manual order-picking from multiple aisles has been the topic of a number...
Contexts in source publication
Context 1
... layout of storage area considered in this paper is the one with parallel pallet racks, as illustrated in Fig. X.1 (left). Aisle-based pallet floor storage has the same characteristics as the pallet rack storage and can be considered in the same way. Operations within such a layout are single cycles, either to store a single unit-load or to retrieve (pick) a single unit- load. Since for a given capacity of storage area (number of storage locations) one ...
Context 2
... of response. Order-picking area layouts that can be found today in the majority of warehouses are the same as for the storage area. The basic form has parallel aisles, a central depot (pick up/delivery point), and two possibilities for changing aisles (i.e. two cross-aisles), at the front and at the rear of the warehouse, as already shown in Fig. X.1. A non-linear programming model for optimal order-picking layout is presented in (Roodbergen, ...
Citations
... Operational costs are the costs of cycles in a considered layout. Most models in the literature optimize the layout minimizing the expected travel distance to store/retrieve an item", Dukic et al. 2012. Let me suggest slightly different point of view. ...
... This value is used to be compared with a warehouse sizes sustainability coefficient in case of any w-variant. Theoretically, according to Dukic et al. (2012), the shape of the resulting optimal layout is rectangular with the proportion of w D : w S = 1 : 2, while in practice it should usually be slightly modified under some circumstances. That is why it is good to check a warehouse sizes sustainability coefficient, while computing different variants in case of checking whether the proportion is reasonable. ...
Designing a warehouse layout is an important problem, which plays a role in a life cycle of a company. Generally, two main types of layout decision problems are mentioned in literature. The first problem is usually called facility layout problem while the second one is internal layout designing problem or aisle configuration problem. Merging them both, the procedure for rational searching of optimal warehouse layout is prepared. It was decided to prepare the procedure as an optimisation procedure of functional and spatial areas. The procedure is a part of the logistics facilities designing method because a sketch layout of logistics facility is an important part of the method of logistic facilities designing. The paper briefly describes the location of the procedure in the method. Regarding functional and spatial layouts designing, model was expanded with mathematical formulas of certain geometrical parameters. Particular emphasis on warehouse geometry is important due to the fact that many other issues depend on these parameters in warehouse designing process. The paper consists of a problem definition, mathematical model formulation and precise descriptions adequate to mathematics notations. What is more, the example of procedure application implemented into the software is given. The software is the implementation of the procedure and the whole method itself.
This paper explores the different approaches to warehouse operations within a supply chain context. It highlights the significance of warehouses in efficiently and effectively meeting customer demands while minimizing costs. The study examines various types of warehouses and analyzes the activities involved in warehouse operations. Furthermore, this paper discusses the challenges and benefits of warehouse operations in developed and developing countries. It emphasizes the need for efficient warehouse management to enhance customer satisfaction, reduce costs, and improve overall productivity. The integration of warehouses into the supply chain process is also emphasized, emphasizing their critical role in facilitating the flow of goods. This paper introduces the Warehouse Management System (WMS) concept as a technological solution for controlling the inflow and outflow of goods. It delves into WMS functions and highlights its importance in inventory control, order management, and system reliability. Additionally, this paper examines the differences between traditional manual warehousing and automated approaches, taking into account factors such as cost, efficiency, and suitability for different types of organizations. In conclusion, the study suggests that automated warehousing is more suitable for larger companies operating in countries with limited manual labor availability. On the other hand, traditional warehousing may be more applicable in developing countries with higher unemployment rates.
There is vast research on particular aspects of warehouse design - layout, material handling, order picking, and operating policies - when, in fact, the decisions involved in the process are interrelated. In this paper, we develop an engineering economics framework for warehouse operations that decomposes the cost structure of the operation and lays out the relationships between them. Our framework decomposes operational costs into four exogenous characteristics (wages, leasing costs, cost of capital, and access to technology) that depend on the geographic location of the warehouse and two operational requirements (throughput and storage capacity). Using these six parameters, and publicly available information, practitioners can estimate the total operational cost of the warehouse for potential locations in facility location analysis, which have been traditionally limited to transportation costs. In our case study, we use our framework to establish a rank of preferable warehouse locations in terms of operational costs among logistics clusters in the United States of America.
Order picking is the part with the highest proportion of operation cost and time in the warehouse. The characteristics of small-batch and multi-frequency current orders reduce the applicability of the traditional layout in the warehouse. Besides this, the improvement of the layout will also affect the picking path, such as the Chevron warehouse layout, and at present, there is a lack of research on order picking with multiple picking locations under non-traditional layouts. In order to minimize the order picking cost and time, and expand the research in this field, this paper selects the Chevron layout to design and describe the warehouse layout, constructs the picking walking distance model of Return-type, S-type and Mixed-type path strategies in the random storage Chevron layout warehouse, and uses the Cuckoo Search (CS) algorithm to solve the picking walking distance generated by the Mixed-type path. Compared with the existing single-command order picking research, the order picking problem of multi picking locations is more suitable for the reality of e-commerce warehouses. Moreover, numerical experiments are carried out on the above three path strategies to study the impact of different walking paths on the picking walking distance, and the performance of different path strategies is evaluated by comparing the order picking walking distance with the different number of locations to be picked. The results show that, among the three path strategies, the Mixed-type path strategy is better than the Return-type path strategy, and the average optimization proportion is higher than 20%. When the number of locations to be picked is less than 36, the Mixed-type path is better than the S-type path. With the increase of the number of locations to be picked, the Mixed-type path is gradually worse than the S-type path. When the number of locations to be picked is less than 5, the Return-type path is better than the S-type path. With the increase of the number of locations to be picked in the order, the S-type path is gradually better than the Return-type path.
In the unit-load warehouse (UW) design, the aisle design problem dealing with storage space layout is the first among the three main problems. Several conventional and non-conventional designs have been proposed in the literature. In general, the assessment of UW designs is commonly carried out using analytical approaches. However, such an approach may be inadequate due to assumptions or approximations, making results unrealistic. Aiming to bridge this gap, this research develops an assessment framework that employs the FlexSim software for simulating the conventional, Flying-V and Fishbone designs based on a real case from a Philippine manufacturing company. Using a computer simulation, this research investigates factors not yet tractable with present analytical methods. The factors employed for the comparative assessment are “picking run-time”, “travel distance”, and “capacity”. The results suggest that the Fishbone design provides the most advantage compared to the Flying-V and other conventional designs. With the proposed Fishbone design, the company is expected to save, on average, 52.39% of picking run-time, 32.25% travel distance, and increase storage capacity by 7.5%. The research findings are compared to previous studies based on analytical approaches.
Order picking has often been considered as one of the most labor- and time-intensive tasks in warehouse operations. Among the various planning problems that have to be solved in manual picker-to-parts systems, the routing of the order picker usually accounts for the highest share of the total warehouse operating cost. To minimize the cost of order picking, researchers have developed various routing procedures that guide the order picker through the warehouse to complete given customer orders. For some warehouse layouts such as the chevron warehouse, an optimal routing algorithm has not been proposed so far. The paper at hand therefore contributes to filling this research gap by developing an optimal order picker routing policy for the chevron warehouse. The optimal routing algorithm proposed in this paper is based on the concept of graph theory and utilizes a dynamic programming procedure. In addition, we propose various simple routing heuristics for the chevron warehouse. In computational experiments, the average order picking tour lengths resulting from optimal routing and from the simple heuristics are compared. Moreover, we compare the performance of the chevron warehouse to the conventional two-block warehouse under various conditions using the tour lengths obtained by the optimal algorithms.
The article presents an approach to assessing the reliability of logistics processes implemented in supply chains in terms of time losses resulting from the selection of a variant of material flows in the supply chain. In order to define this indicator, a mathematical model of the supply chain has been developed, i.e. the parameters of the research problem, the decision variables, the constraints and the evaluation criteria. The method of evaluating the reliability of the system is presented in diagram form. The algorithm was verified based on experimental data. In order to evaluate the reliability of the logistic processes for the sample supply chain, a simulation model was developed that determines the time losses in the points and linear elements of the examined chain. Time losses are dictated by traffic delays resulting from traffic congestion on particular sections of the route and road junctions and delays in point elements in the supply chain.
In this paper, we provide a method to generate a three-dimensional detailed design of fishbone layouts. This method takes the desired storage capacity and returns the location (x,y,z) of each opening of the warehouse in such a way that the total operational cost - area cost and material handling cost - of the warehouse is minimal. We model the arrangement of the openings using mathematical finite sequences and represent a fishbone layout in terms of four primary characteristics. Next, we develop an algorithm that generates a detailed design of a fishbone layout given values of its four primary characteristics. Then, we present an optimization model that finds the values for the four primary characteristics that minimize the total operational cost of the warehouse. Finally, we solve the optimization model using a genetic algorithm. Our results suggest that in 91.74% of the cases, our optimization procedure reaches a near optimum point - deviated only by 0.587% - in a reasonable computational time (maximum 4.5. min). This paper aims to diminish dependence upon experts and human decision making in the process of implementing a fishbone layout on greenfield projects, and fulfills an identified need of warehouse practitioners by integrating the most recent advances on non-traditional layouts and detailed warehouse design.
This paper presents some approach for the formulation of the decision-making model in supporting the assessment of supply chain efficiency. Were presented factors affecting the efficiency of the functioning of individual links of supply chain. Was pointed out the technical, economic, organizational and reliability aspects affecting the efficiency and reliability of functioning of the supply chain both in terms of supply and distribution. Having regard to a comprehensive approach to assessing efficiency of the functioning of supply chains were proposed indicators for assessing the quality of functioning. Were distinguished technical, economic and quality indicators for which also were presented a formal record.
