A warehouse control system (WCS) is a software application that directs the real-time activities within

warehouses A warehouse is a building for storing goods. Warehouses are used by manufacturers, importers, exporters, wholesalers, transport businesses, customs, etc. They are usually large plain buildings in industrial parks on the rural–urban fringe, outs ...

and

distribution centers A distribution center for a set of products is a warehouse or other specialized building, often with refrigeration or air conditioning, which is stocked with products (goods) to be redistributed to retailers, to wholesalers, or directly to con ...

(DC). As the “traffic cop” for the warehouse/distribution center, the WCS is responsible for keeping everything running smoothly, maximizing the efficiency of the material handling subsystems and often, the activities of the warehouse associates themselves. It provides a uniform interface to a broad range of material handling equipment such as AS/RS, carousels,

conveyor systems A conveyor system is a common piece of mechanical handling equipment that moves materials from one location to another. Conveyors are especially useful in applications involving the transport of heavy or bulky materials. Conveyor systems allow ...

, sorters, palletizers, etc. The primary functions of a WCS include: * Interfacing to an upper level host system/ warehouse management system (WMS) and exchanging information required to manage the daily operations of the distribution center. * Allocating work to the various material handling sub-systems to balance system activity to complete the requested workload. * Providing real-time directives to operators and material handling equipment controllers to accomplish the

order fulfillment Order fulfillment (in British English: order fulfilment) is in the most general sense the complete process from point of sales inquiry to delivery of a product to the customer. Sometimes, it describes the more narrow act of distribution or the ...

and product routing requirements. * Dynamically assign cartons to divert locations based on defined sortation algorithms or based on routing/order information received from the Host (if applicable). * Generate result data files for reporting and/or upload by the Host system. * Operational screens (

graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

) and functions to facilitate efficient control and management of the distribution warehouse. * Collect statistical data on the operational performance of the system to enable operations personnel to maintain the equipment in peak performance. Each major function is designed to work as part of an integrated process to effectively link the host systems with the lower level control system, while relieving the Host from the real-time requirements such as operator screens and lower level equipment control interfaces.

Control hierarchy

The typical warehouse/distribution center consists of a multi-tier control architecture in which each level in the control hierarchy has a defined role. The upper most level of the control hierarchy is the warehouse management system (WMS), or host. This system handles the business aspects of the system such as receiving customer orders, allocating inventory, and generating shipping manifests or bills of lading) and invoices based on order fulfillment information and shipping information received from the material handling control system (WCS). It typically interacts with the material handling system on a non-real-time basis. Coordinating the activities of the various material handling sub-systems is the role of the warehouse control system (WCS). The WCS directs the "real-time" data management and interface responsibilities of the material handling system as well as provides common user interface screens for monitoring, control, and diagnostics. As the focal point for managing the operational aspects of the material handling system, the WCS provides the critical link between the non-real time based host and the real-time MHE control system. It receives information from the upper level Host and coordinates the various real-time control devices (conveyors, print and apply applicators, etc.) to accomplish the daily workload. At each decision point, the WCS determines the most efficient routing of the product and transmits directives to the equipment controllers to achieve the desired result. At the lowest level, closest to the physical equipment, are the equipment controller(s). These controllers are typically some form of a

programmable logic controller A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity tha ...

(PLC) or a dedicated, real-time PC control system. They interface to peripheral

Input/Output In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...

(I/O) devices such as photo-eyes scanners, motors, etc. as well as data collection devices such as bar code scanners (

barcode reader A barcode reader is an optical scanner that can read printed barcodes, decode the data contained in the barcode to a computer. Like a flatbed scanner, it consists of a light source, a lens and a light sensor for translating optical impulses into e ...

) and weigh scales and are responsible for the physical operation of the material handling equipment. The equipment controllers are also responsible for the physical handling of product and tracking it from point-to-point based on the direction from the upper level control systems. Typically a single controller is only concerned with the operations of a defined area or sub-system of the overall material handling system. Ultimately, the control hierarchy within the distribution center reflects the organizational structure of their human counterparts. The management staff (or the WMS) determines the workload to be accomplished for the day while the supervisory staff (WCS) oversees the real-time activities of the warehouse associates (equipment controllers) to complete the daily activities. Each warehouse associate is assigned a specific task based on their area of expertise (order selection – carousel/Pick To Light, transportation - conveyors, etc.). As each operator completes their individual assignment, the supervisor (WCS) assigns the next task based on the current workload. As orders are completed, the (WCS) supervisor reports back to (WMS) management the status of the orders along with any pertinent order information.

Best practice

*Have one WCS in your distribution center *Design a lean interface between WCS and WMS *Define responsibilities between WCS and WMS (who owns the inventory?)

References

Modern Materials Handling Magazine: "Simon & Schuster Implements Warehouse Control System" by Bob TrebilcockModern Materials Handling Magazine: "Oriental Trading Company gets its warehouse under control" by Bob TrebilcockDC Velocity: "Who's In Charge" by James Aaron Cooke"A Top Tier WCS Increases Productivity in Omni-Channel Distribution" by Jen Maloney
* ttp://www.factoryautomationresource.com/category/warehouse-control-systems-and-software.html "List of WCS's" added by Rudi Lueg{{refend Industrial computing

Control hierarchy

Best practice

See also

References