Share Warehousing distribution picking path method
Issuing time:2018-11-09 15:16
In recent years, with the development of e-commerce and the requirement of production punctuality, the scale of orders has become smaller and smaller, even unpacking and sorting. Unpacking sorting is also known as small order sorting or single item picking or split picking. Small order sorting corresponds to other sorting units, ie pallet sorting, bin sorting. Although many successful automatic sorting systems are currently used in warehousing operations, since the warehousing and sorting system is a non-static, non-disposable activity, and the automatic sorting system is not only costly but also less flexible, manual division The picking system still has some practical significance. The following are mainly several routes for manual small order order picking.
01, sorting path
The latest warehousing survey report shows that order sorting is the top priority for improving warehouse productivity. Sorting costs will account for 65% of warehouse operating costs, and studies have shown that the walking time of sorters will account for the total score. Pick up 50% of the time. It can be seen that reducing the walking time of the sorting personnel is meaningful for improving the sorting efficiency and reducing the operating cost of the warehouse. The walking time of the sorting personnel is related to many factors. Among them, the reasonable arrangement of the sorting path is an effective measure to reduce the walking time.
The goal of the sorting path is to determine the picking order of the items on the sorting order, and to reduce the walking distance of the sorting personnel by heuristic or optimized paths. In practice, people usually apply heuristic sorting paths. This is mainly because the path generated by the optimization may not meet the logic of the sorter's usual work and is not easy to operate; moreover, the optimized path does not consider the line congestion problem.
02, crossing path
There are several heuristic sorting path methods for single-zone warehouse sorting operations, namely traversing, returning, midpoint rotation, maximum gap, and combination strategy. In addition, there are split traversal strategies, split return strategies, and channel-to-channel policies for applications in multi-zone layouts. The various heuristic sorting paths are described below.
The traversing path method is simple and easy to implement, and many warehouses are in use, especially for high picking density. When the crossing path is adopted, the person picking up from one end of the channel picks up the items on both sides of the channel at the same time, and finally leaves the other end of the channel. Before returning to the entrance and exit, the sorter will travel through all the channels that contain the picking location. Since the walking path is approximately "s" shaped, it is also called the "s" shaped path, as shown in Figure 1.
When the number of lanes distributed by the picks is even, the crossing strategy must cross each lane with the selected items; when the number of lanes distributed by the picks is odd, except for the lane where the last item is being picked, the other lanes All need to be crossed. Therefore, the walking distance in the picking lane in the crossing strategy is completely dependent on the number of lanes in which the picks are distributed.
03, the swing path
In the slewing path method, the picker enters from one end of the sorting channel, first picks up the required items on one side of the shelf along the way, and when the items on one side of the shelf are picked up, returns to start picking the other side of the shelf. The item finally leaves from the end of the entry channel. The picker only needs to enter the channel containing the picking position, and the channel that does not contain the picking position can be skipped, as shown in Figure 2.
If a return strategy is adopted, the distance of picking travel should be shortened, so that the position of the picked goods entering the roadway should be as short as possible. That is to say, if the distribution of the picked items shows a tendency to distribute toward one end of the shelf, the shorter the walking distance during the returning process, the shorter the total walking distance can be achieved by using the returning strategy.
04, midpoint rotation, split rotation
The midpoint rotation strategy divides the sorting area into two parts from the midpoint of the picking path, as shown in Figure 3. The picker enters from one end of the passage, and after the goods are picked up, the turn is turned back. The farthest point is the midpoint of the passage. When the picker leaves the first half of the picking area, the picker must pass through the rightmost passage. In the second half of the channel, the second half of the pick is started in the same way. When the second half of the pick is completed, cross the leftmost channel to return to the population. This is not only the revolving method but also the traversal strategy when entering and exiting the rear half of the channel. In addition, there is a strategy called split slewing, which is very similar to the midpoint slewing strategy, as shown in Figure 4.
The split slewing strategy requires that the entire picking area be divided into two parts, the front and the back, but the dividing point is not necessarily bounded by the center point.
It can be seen from the walking rules of the midpoint strategy that the walking in other lanes is similar to the return strategy except that the leftmost lane and the right lane must pass. To shorten the picking distance, the distance between the picked position and the ends of the roadway should be as short as possible. If the distribution of the picked items is concentrated on both ends of the shelf, the shorter the distance traveled back in the roadway, the shorter the total walking distance can be achieved by using the midpoint strategy.
05, maximum gap, channel connection channel
The maximum clearance strategy refers to comparing the distance between the goods to be taken in the same channel and the bottom and bottom channels of the upper and lower sides, and selecting the path of the shorter distance. If the distance between the goods and the bottom end of the upper and lower sides is less than the minimum between the goods The distance is directly rotated, as shown in Figure 5. The maximum gap strategy is similar to the midpoint strategy. The difference between the two is that under the maximum gap strategy, the sorter can reach the maximum gap rather than the midpoint.
The channel-to-channel strategy is a heuristic for a warehouse with multiple horizontal channels. In general, each longitudinal channel is accessed only once. The sorter starts at the population and then enters the leftmost channel for the item to be picked. When all items in one longitudinal channel are selected, a transverse channel is selected to enter the next longitudinal channel. The method entails determining a transverse channel that transitions from one longitudinal channel to the next. As shown in Figure 6.