Warehouse control system
Encyclopedia
A warehouse control system (WCS) is a software application that directs the real-time activities within warehouses and distribution centers. 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, sorters, palletizers, etc. The primary functions of a WCS include:
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.
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
(PLC) or a dedicated, real-time PC
control system. They interface to peripheral Input/Output
(I/O) devices such as photo-eyes scanners, motors, etc. as well as data collection devices such as bar code scanners (barcode reader
) 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.
- Interfacing to an upper level host system/Warehouse management systemWarehouse management systemA warehouse management system, or WMS, is a key part of the supply chain and primarily aims to control the movement and storage of materials within a warehouse and process the associated transactions, including shipping, receiving, putaway and picking...
(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 fulfillmentOrder fulfillmentOrder fulfillment is in the most general sense the complete process from point of sales inquiry to delivery of a product to the customer...
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 interfaceGraphical user interfaceIn computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
) 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
Bill of lading
A bill of lading is a document issued by a carrier to a shipper, acknowledging that specified goods have been received on board as cargo for conveyance to a named place for delivery to the consignee who is usually identified...
) 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
Programmable logic controller
A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
(PLC) or a dedicated, real-time PC
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
control system. They interface to peripheral Input/Output
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
(I/O) devices such as photo-eyes scanners, motors, etc. as well as data collection devices such as bar code scanners (barcode reader
Barcode reader
A barcode reader is an electronic device for reading printed barcodes. Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating optical impulses into electrical ones...
) 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.
See also
- Document automationDocument automationDocument automation is the design of systems and workflow that assist in the creation of electronic documents. These include logic based systems that use segments of pre-existing text and/or data to assemble a new document. This process is increasingly used within certain industries to assemble...
for Supply Chain and Logistics - Enterprise resource planningEnterprise resource planningEnterprise resource planning systems integrate internal and external management information across an entire organization, embracing finance/accounting, manufacturing, sales and service, customer relationship management, etc. ERP systems automate this activity with an integrated software application...
(ERP) - Inventory management softwareInventory management softwareInventory management software is a computer-based system for tracking product levels, orders, sales and deliveries. It can also be used in the manufacturing industry to create a work order, bill of materials and other production-related documents. Companies use inventory management software to...
- Manufacturing resource planningManufacturing resource planningManufacturing resource planning is defined by APICS as a method for the effective planning of all resources of a manufacturing company...
- Warehouse management systemWarehouse management systemA warehouse management system, or WMS, is a key part of the supply chain and primarily aims to control the movement and storage of materials within a warehouse and process the associated transactions, including shipping, receiving, putaway and picking...
(WMS)