Depending on the nature of the product and the location of cross-docking in the supply chain, various detailed solutions can be distinguished. It has become common to locate cross-docking in the distribution area, i.e., in the part of the supply chain where the finished product is moved within individual links of distribution. This does not exhaust its possibilities, and furthermore, various detailed solutions are possible in every part of the supply chain.
Methods of cross-docking
<\/strong>Depending on the company’s location in the supply chain, we distinguish the following ways of applying cross-docking [1,2,3]:<\/p>
Cross-docking in a manufacturing company (manufacturing crossdocking<\/em>).<\/strong>
Manufacturing crossdocking<\/em> is a way of moving finished products to loading docks in a manufacturing company, without storage, used for the needs of consolidation and release of a specified quantity of products or sets of component batches typical for the factory’s product recipients, or preparing assembly while supporting production in a Just-in-Time<\/em> system. The following implementation variants are distinguished:<\/p>
• releasing finished products from the production line and moving them directly to waiting semi-trailers at the transshipment gate of the production plant / production department, finished goods warehouse (Fig. 1).
• releasing finished products from temporary storage stations (staged<\/em>), located in the warehouse for later release. Products from production are successively transferred to the warehouse to a designated temporary storage area, from where they are released (Fig. 2).<\/p>
Typical cross-docking in an industrial enterprise is used for releasing finished products in full load units. A real-time Warehouse Management System (WMS) is required to manage the flow. Movement activities in an industrial enterprise (in production and the warehouse) for load units are performed using forklifts.<\/p>
Cross-docking in a distribution company (distribution crossdocking<\/em>).<\/strong>
Cross-docking used in distribution warehouses carries out many diverse commercial activities and the resulting physical operations, such as segregation, merging, and consolidation of goods for various recipients into single or multi-assortment load units.
Typical for cross-docking in a distribution center is participation in operations linking several manufacturers, creating various complementary sets of assortments, which are then sent to various recipients who assemble deliveries from them for the next level of the supply chain. Goods in cross-docking during distribution are received and released in the form of full load units, in mobile containers, or in transport packaging. Movement activities in a distribution warehouse for pallet load units are carried out using efficient forklifts, and for units in mobile containers – efficient pallet trucks; whereas for cardboard packaging, segregation and internal transport processes are performed in sorting conveyor systems.<\/p>
In distribution center warehouses, the following basic methods of conducting cross-docking can be distinguished:
• direct cross-docking (Pure crossdocking<\/em>).<\/strong> A transshipment system intended for single-stage, direct movement of loads from the warehouse receiving gate to the warehouse release gate, from semi-trailer to semi-trailer, of pallet load units or bulk packaging (Figures 3 and 4).<\/p>
The execution of transshipment operations requires – apart from general requirements – the fulfillment of the following conditions:
1. the presence of arriving and departing semi-trailers at the same time,
2. identification of packaging via barcode labels or radio frequency identification (RFID) tags,
3. an appropriate size and number of warehouse gates for receiving and releasing to the warehouse.<\/p>
Variations of transshipment:
1. transshipment of load units from and to semi-trailers of different sizes in road transport,
2. transshipment of parcels in hubs and in internal deliveries (multi-assembly installations) for recipients according to standardized routes served by small delivery vehicles.<\/p>
• temporary storage (Short-term Staging<\/em>).<\/strong> A transshipment system in which assortments from incoming semi-trailers are stored in the warehouse for a short period of time or accumulated (not stored) on a temporary storage area, and then loaded onto outgoing semi-trailers. This method allows incoming shipments to be divided and directly received or accumulated for further distribution.<\/p>
The execution of this type of transshipment requires, apart from general requirements, the fulfillment of the following conditions:
1. additional space for temporary storage,
2. additional time between internal receipt and external release.<\/p>
The article comes from the magazine “Logistyka” 2/2009.<\/p>