Although double depth shelves have significant advantages in space utilization, they also have obvious limitations due to the structural characteristics of "deep storage and reduced channels". They mainly focus on three dimensions: access efficiency, operational flexibility, and cost adaptation, as follows: The storage and retrieval efficiency is limited, and there is a "first in, first out" problem: the double depth shelves store 2 rows of goods along the depth direction. If the inner (deep) goods need to be retrieved, the outer goods must be removed first, which naturally follows the "first in, first out" storage logic. This can lead to cumbersome operations for high-frequency storage and retrieval of goods, especially not suitable for scenarios that require "first in, first out" management (such as fresh produce, food with short shelf life, and chemical products with batch management requirements), and the single storage and retrieval operation time is 20% -30% longer than that of ordinary crossbeam shelves. High requirements for operating equipment and personnel: specific equipment (such as forklifts with telescopic forks, forward moving forklifts) are needed to access deep goods, which ordinary balanced weight forklifts cannot adapt to; At the same time, operators need to master precise fork picking techniques (such as controlling the depth of the telescopic fork and aligning the cargo position). If the operation is not proficient, problems such as cargo collision and shelf deformation are likely to occur, indirectly increasing equipment procurement costs (the unit price of specialized forklifts is usually more than 50% higher than ordinary forklifts) and personnel training costs. Difficulty in inventory management and low inventory efficiency: Deep goods are obstructed by outer goods, and conventional manual inventory requires moving the outer goods to check the inner inventory, which not only consumes time and effort (inventory efficiency is about 40% lower than ordinary shelves), but also easily leads to inventory errors due to obstruction; If not equipped with WMS (Warehouse Management System) or location visualization equipment, it may be difficult to real-time grasp the inventory status of the inner goods, which may result in "discrepancies between accounts and reality". Poor flexibility, not suitable for multi variety and high-frequency turnover goods: The shelf structure is fixed, and the depth and width of the cargo space need to be designed according to the preset cargo specifications. If the cargo specifications change in the future (such as changing from a whole pallet of large items to small batch of small items), the shelf adaptability is low and the transformation cost is high; At the same time, for goods with multiple varieties, small batches, and high-frequency storage and retrieval (such as e-commerce multi SKU products and scattered parts outbound scenarios), frequent "moving out and taking in" operations will seriously slow down overall operational efficiency, and may not be as flexible as ordinary shelves.
