COMPUTER MODELING OF WAREHOUSE LOGISTICS PROCESSES: TECHNOLOGY OF RATIONAL SLOT SELECTION FOR PICKER’S ROUTE MINIMIZATION

Abstract

The article is devoted to solving scientific and practical problems of increasing the efficiency of logistics systems by minimizing the duration of material handling equipment (MHE) routes using the example of picking orders in warehouses with shared storage. The order picking process is one of the most labor-intensive and expensive operations, as the movement of staff or machinery accounts for over 50 percent of the total picking time. When goods are scattered throughout the warehouse, an additional problem arises regarding the rational selection of slots for picking goods in accordance with the order. To ensure the rational selection of locations, the PIV (Proximity Indexed Value) multi-criteria decision-making method was applied in this study. The locations of a particular item are considered as alternatives, each characterized by different criteria. Three criteria have been selected. To evaluate the alternatives (slots) according to the criterion 'degree of satisfaction of demand for other items in the order', it is proposed to take into account the potential of adjacent locations.

A hypothesis has been formulated regarding the impact of sorting goods within orders for the subsequent application of the PIV method. A heuristic for the preliminary ranking of items within orders has been justified and proposed, based on the scarcity of alternative locations in the warehouse, thereby implementing the principle of 'limited choice'. To verify the hypothesis, a three-dimensional simulation model of the goods storage area of the sorting center with a capacity of 360 unique slots was developed. Computer modeling in the MATLAB environment allowed us to recreate the topological labyrinth of the warehouse, record the coordinates of the aisles between racks and the operational routes, and ensure that virtual equipment moved strictly along the center lines of the aisles via designated access points. As part of experimental research, a comparative analysis of route construction using the nearest neighbor algorithm for two scenarios was performed: classical processing of the consignment note “top-down” and processing according to the proposed principle of “limited choice”. The results of a series of computer experiments for order waves of 5 to 15 items confirmed the validity of the hypothesis and showed a reduction in the total duration of the material handling equipment route by 2–9% when processing an order according to the principle of limited choice.