Typically there are three main types of picking. The first one corresponds to the principle: person to goods (the picker must move in the warehouse to the location of each unit). In the second case, the goods reach the person (the operator does not leave the picking station, and the appropriate device moves the goods to this place and places them within reach). This is currently the most common picking in automated warehouses.
An example of the picking concept goods-to-person is the vertical storage system used in VBH (the company offers window and door hardware, such as locks and hinges). All small parts are stored in several vertical storage systems with a height of more than 5 m and making full use of the vertical space of the warehouse (to the ceiling). Small parts are stored directly at the pallet warehouse.
The pick-by-light system helps in quick picking. After confirmation, the order is sent to the point of retrieval. The LED display indicates the number of items to be assembled and the light beam indicates the correct goods. The retrieved items are transferred to picking containers, which are located on a conveyor located opposite the picking point. All packing boxes can be identified by the LED indicator. Thanks to vertical storage systems it is possible to process large order lists at the same time in a very short time. Each week it is about 1,300 orders containing up to 20,000 items each time.
The third is a mixed system (in one warehouse it is possible to use storage systems operating according to different rules selected for a given type of product).
Considering its economic importance, when designing the picking process, it is necessary to first analyse the movement of goods in the facility necessary to perform the work related to the selection and extraction of items. Only then should one of the three solutions be selected.
Among the more or less conventional methods and techniques of entering and controlling information during the picking process in “manual” systems are:
– picking lists based on order printouts and/or adhesive labels,
– communication systems (shelf displays – pick-to-light systems; audio communication systems).
Usually, there are also scanners and portable terminals with radio communication systems at the disposal of order pickers. The latter are considered to be a synonym of a sort of revolution in picking systems. The order information is loaded into the terminal and the instructions for the operator are displayed on the screen of the device. Instructions appear in the optimum sequence in which the employee will be picking the order. At the moment of retrieval, this action is confirmed and the next instruction is displayed.
This process can also be integrated with an internal control system. For example, on the terminal screen, only the code of the location of the goods to be retrieved is displayed. The employee arrives at the indicated place and scans the label on the packaging, or the location code.
The pace of work can be increased by using solutions that combine voice, scanning and visual guidance; employees can perform tasks without using their hands, without compromising accuracy.
Mobile devices simplify the order picking process and increase productivity. Thanks to them you can determine the optimal route to a given product, verify the correctness of selection on the spot and update the status of stocks in the system on an ongoing basis. Verification of each transaction using the scanning function, which does not require manual operation, or with the help of voice commands helps to maintain documentation in an orderly manner.
Specialists have calculated that voice solutions provide 99% accuracy and can increase warehouse productivity by at least one-tenth
In a typical manual warehouse, it is possible to use different order preparation or picking systems depending on the requirements of the product. For lightweight loads, shelving racks are used (also in the version with a platform or mobile base). An alternative solution is e.g. a racking system served by the order picking trolley. There are also racks operated by triple-sided combi system trolleys, as well as flow-shelf racks. Advanced picking solutions are based on automated warehouses with stacker cranes (miniload).
Faster picking with robots
Other solutions are also under development, e.g. Chuck, a collaborative logistics robot, which made its debut during LogiMat. The solution is to enable an increase in the number of operations by 200-300% in comparison with hand trucks. Developed by former managers of Kiva Systems (now Amazon Robotics), Chuck can be integrated into any warehouse. It requires no additional infrastructure and is compatible with any WMS.
Generally speaking, the solution eliminates long “walks” around the warehouse and speeds up the execution of tasks. The Chuck fleet helps to perform three key storage operations: input, picking and output. Chuck communicates with the software, an employee places the appropriate boxes or containers on the trolley, and the trolley is directed to the pickers in the picking area.
The built-in scanner captures all product information, including batch and serial number validation in real time. The destination can be a packaging stand or a separate picking zone.
Photo: Baumalog