There is a significant shift between (Warehouse Management Systems) WMS and WCS (Warehouse Control Systems) in the area of merging local data warehouses into enterprise data warehouses.
This convergence is being caused by:
- Technology Advancements: The use of open software, relational databases and componentized applications architectures are enabling WMS vendors to provide real-time data management and interface responsibilities of the material handling system.
- Functional Enhancements: The WMS has, over time, taken over more of the work handled by the ERP system, in areas such as inventory control, resource scheduling and order management.
New software tools are also enabling continuous monitoring and work flow functionality, thereby providing the means to efficiently and economically operate a warehouse or distribution center.
Consider the WCS a floor general or a traffic cop. Capturing real-time data such as pick rates and pick efficiencies are more geared toward this type of system than to a generic WMS focused on upper level management data.
Traditionally, a WCS executes instructions provided by an upper-level host system, such as an ERP or WMS system. True Tier 1 WCS software, such as QC Software WCS Enterprise Suite, FKI Logistex WCS, and HighJump Software, provide advanced management capabilities including inventory control, resource scheduling and order management.
These best-of-breed WCS systems are modular in nature, easily configurable, and platform independent, with a scalable architecture to satisfy the needs of any size warehouse. Not all companies require all the functionality within a WCS, but it is imperative that this functionality can be "plugged in" at any time.
Unlike a typical WMS, WCS directs real-time data management and interface responsibilities for the materials handling system and provides common user interface screens for monitoring, control, and diagnostics.
Optimal WCS on a Component Level
A standard WCS contains the following components:
- Conveyor Routing
- Sortation
- Communication with host ERP/WMS
- Communication with Material Handling Equipment
A Tier 1 WCS includes the following:
- Conveyor Routing
- Sortation
- Communication with host ERP/WMS (less communication/data passing is needed due to the fact that the WCS is doing more of the WMS functionality)
- Communication with Material Handling Equipment
- Cartonizing
- Zone skipping
- Inventory Management
o Location Control
o Receiving
o Put Away
o Replenishment
o Cycle Counting
- Wave Planning
- Picking/Order Fulfillment
- Multi-carrier Shipping
As the focal point for managing the operational aspects of the material handling system, WCS provides a critical link between the batch-time data host and the real-time Programmable Logic Controller (PLC) material handling system.
The PLC coordinates the various real-time control devices to accomplish the daily workload. At each decision point in the distribution process, the WCS "determines" the most efficient routing of the product and transmits directives to the Equipment Controllers to achieve the desired result. The decision-making process often is controlled by two separate utilities, the Sort Manager and the Route Director.
Inventory Management System
Few Warehouse Control Systems contain an Inventory Management System (IMS) because typical WCSs simply manage the conveyor routing and sorting and have not been developed with other business functions in mind.
Software packages that have this feature use Linux, Java, and robust databases to enhance the accuracy and efficiency of warehouse operations and data integrity. IMS manages all item numbers and warehouse locations. The major inventory events of an IMS process include bar code label printing, receiving, put-away, cycle counting, picking, and replenishment.
IMS controls the replenishment between bulk storage locations and pick locations. The replenishment engine continuously monitors inventory levels of active pick locations and automatically generates replenishment tasks based on a minimum quantity threshold set for each item. Replenishment tasks can also be generated manually in anticipation of increased activity for an item.
IMS allows for multiple methods of counting to ensure inventory accuracy. Counts may be taken based on Location, Item, Last Cycle Count Date, or Velocity. Full reconciliation and discrepancy reports should be provided as well as the capability to track all cycle count history.
An IMS normally includes:
- Barcode Label Printing to produce labels for locations, items, and shipping; utilizes various methods including automated, in-line print and apply technology.
- Full functionality for receiving goods into the warehouse; utilizes Portable Data Terminals (PDT) allowing product to be received more efficiently.
- Random or directed put-away of goods within the warehouse; also provides the capability to move items between locations.
- Picking function to adjust inventory levels based on pick transactions from a PDT or other picking system, such as Pick-to-Light; allows full traceability of inventory transaction movements within the system.
Order Management System
An Order Management System (OMS), meanwhile, provides the functionality necessary to properly and efficiently execute the order fulfillment process. This module should be included with the WCS purchase. OMS facilitates the planning, processing, verifying, and shipping of orders within the warehouse or distribution center.
Planning orders for optimized picking is the most essential aspect in the order fulfillment process. The OMS must be a configurable tool that allows orders to be streamlined for picking efficiency, and should allow the utilization of Wave Planner and Scheduling functions; the most efficient picking technique will be determined whether product processing single line/single quantity orders, multiple line orders, or ship alone orders.
The OMS releases the proper number of Pick Tasks to maintain a fluid work load. The OMS also provides functionality to select the proper carton(s) for shipping an order by analyzing the makeup of each order to select the proper sized shipping container.
The OMS should enable:
- Items to be allocated to the various containers based on weight, dimension, and pick zone location in order to minimize the number of containers routed to each zone for a single order.
- Manual and/or automated picking solutions such as pick tickets, carousels, Pick-To-Light (PTL), and RF terminals to be used; the feature must allow for multiple picking methods such as Batch or Cluster Picks.
- Pick request messages from the various picking sub-system controllers to track the status of each order and ensure order integrity.
- Order tracking status throughout the process and provide real-time management statistics.
The Shipment Management System (SMS) is a software tool that provides reliable parcel and LTL shipment manifesting. SMS is integrated into the normal operation and streamlines daily shipping routines. Label printing, carrier-compliant documentation, and e-mail notification are just some of the tasks that can be handled by a strong SMS module within a WCS suite.
SMS technologies must support shipping in North America and Europe and include manifesting with the following carriers: UPS, USPS, LTL, DHL, Purolator, Canada Post, and Canpar. Whether utilized along with a WCS suite or in a stand alone environment, or integrated with current supply chain solutions, SMS is a proven shipping solution for any distribution environment.
The SMS should enable:
- Shipment notification via email for enhanced customer support.
- Customized shipping solutions to be integrated to enhance distribution and warehousing needs.
- API-based integration tools to be used to successfully execute shipping functionality.
- Multi-Carrier functionality managed via one interface screen.
The Changing Face of Control Systems in the DC
The expanding role of warehouse control systems will only continue as WCS solutions provide management and control functionality for material handling and data collection control. Since WCS also acts as middleware -- integrating WMS with various material handling controls within the warehouse -- the significance of this technology will only continue to expand.
Many WMS software solutions claim that a WCS component is contained; caveat emptor (buyer beware). The vendors above either have a specific WCS component or contain a genuine WCS suite.
Thomas R. Cutler is the founder of the Manufacturing Media Consortium of twenty seven hundred journalists and editors writing about trends in manufacturing. Cutler is a frequently published author within the manufacturing sector with more than 300 feature articles authored annually; he can be contacted at trcutler@trcutlerinc.com.