A Basic Guide To Material Handling And Warehouse Management

The era of distribution automation is upon us. After years of neglect, supply chain automation has been pushed to centerstage. Now corporate management can't spend enough time or energy on it. Inventory that has historically been viewed as an asset is now a liability. For many firms this attention relates directly to distribution center automation. Many managers are asking themselves where to start first: new automated equipment or better software systems.

The answer in a nutshell is yes to both. Automated equipment and software systems provide incredible gains in efficiency. However, they are not independent. Successful automation projects consider them integrated components to be evaluated and considered in concert with one another.

First, a primer on the new technologies available in the market.

Automated equipment for parcel distribution can be viewed as falling into three categories: storage systems, picking systems and sorting systems.

Storage system advances range from simple upgrades to flow racks to more complex storage systems such as carousels. Simple, yet effective flow rack allows picking from the one side of the rack and concurrent replenishment to occur on the other side of the aisle. Pick facings on flow rack are dense, thereby allowing efficient travel while including sufficient storage behind the facing, appropriate for the demand on the item. Carousels come in horizontal and vertical varieties. The best analogy is the dry cleaner's system, where the pick location (garment on a rail) comes to the associate instead of the associate traveling to the pick location to retrieve the garment. Carousels provide very dense storage best suited for small items or parts. The vertical variety includes additional features such as a very small footprint and security controlled access.

Automated picking systems include pick-to-light and auto-dispensing systems such as an A-frame picker. Pick-to-light is a technology that allows users to visually identify a pick location by means of a light, learn the pick quantity from a small numeric display (LCD or LED) and confirm or sort the picks by pressing a button at the point of pick. Pick-to-light allows hands free, fast picking, with point-of-work confirmation. Auto-dispensing systems automatically deposit merchandise into shipping containers (plastic totes or corrugated shipping boxes) as they pass under the module. The shipping containers are tracked and the correct quantity drops automatically into the correct shipping container, consistent dimensions (audio, video product, books, CPG). The slowest link can be in replenishing the product cartridges.

Outbound sorting systems include various sorting technologies to facilitate carton sorting to shipping lanes or unit sortation to pack stations. The sorting technologies (cross belt, pop-up wheel, tilt-tray, bomb bay, etc.) are going to be dependent on the product characteristics such as weight, size, density, etc. Products can be picked in aisles with take-away conveyors or can be inducted at stations. In a shipping lane, sort, cases or totes are diverted by carrier or route to the appropriate shipping door and can be fluid loaded, in the case of parcel carriers. In a unit sort environment, product is sorted at the unit level (broken cases) to pack stations. Certain products can be diverted directly into the shipping container. This unit sortation allows picks to be batched together to pick the aggregate quantity for the wave, significantly reducing the number of picks and trips for the batch of orders. Naturally the larger the batch, the greater the gain in efficiency.

In addition, in-line shipping systems can allow such advanced features as in-line scanning for shipping confirmation, in-line label application and in-line scales for weight capture and/or pick/pack verification.

Computer software solutions to manage and control warehouse operations fall into two broad categories, warehouse management systems (WMS) and warehouse control systems (WCS). Warehouse management systems allow precise management of all activities within the four walls of a distribution center. These activities include receiving, put-away, storage management, picking, packing, shipping, workforce management, work planning and warehouse set-up and analysis. Warehouse control systems provide computer control of automated equipment, such as many of the items discussed above in the Hardware section. Although not all software developers provide both solutions, most WMS providers offer a WCS solution as well.

Advances in WMS software technology allow users many significant benefits. These benefits include using technology to provide: point of work confirmation, increased accuracy and efficiency, accountability and performance measuring and what-if work planning.

Advances in WCS software technology allow seamless integration with material handling equipment such as storage systems, picking systems and sorting systems. These systems allow users to maximize the benefits of this equipment and use it to its fullest potential. In addition, flexible packaged WCS products allow users to change equipment, strategies and functions without incurring major software modification risks and costs.

An Integrated Approach
As you consider upgrading your software systems that manage distribution operations, it is important to take a whole view of the operation and components. Considering the pieces separately will limit your ability to flex and expand as market conditions and process changes dictate. Purchasing either automation equipment or warehouse software without fully considering the impact on the other is nearsighted at best. The best approach is an integrated one that not only considers the whole solution today, but also prepares the organization for unforeseeable changes that lay down the road.

When an integrated approach is adopted and the material handling system and the warehouse software solution are well integrated, operations really benefit. For example, system defined item weights can be used to eliminate the need to weigh parcels for rate calculation. Another example: an in-line weight scale can be used to confirm the case contents as a weight check (most appropriate if items have unique weights). Another example: product packing characteristics such as weight, cube and dimensions can be used to cartonize the order.

In cartonizing, the software determines how an order should be packed (how many shipping cartons and what size). This can be used to eliminate pack stations, by either sorting units into the correct cartons for unit sortation or instructing the picker what cartons to pick into in a pick-pack environment.

Lastly, in a unit sort environment, dynamic lane assignment can be used to plan waves for more packing chutes than physically available. In this scheme, the re-circulation capacity of a sorter is used to allow induction of product that does not currently have an available chute. Once a chute is freed, the system dynamically assigns the available chute and begins sorting the recirculating product to that chute. In addition, wave boundaries can now be flexible allowing for continuous operation avoiding down time at the end of each wave. Dynamic lane assignment can dramatically increase wave size simultaneously improving picking efficiency and improving sorting efficiency.

As competitive pressures dictate improvements in supply chain efficiencies, firms naturally look to warehouse operations for improvement. And advances in technology will allow for fantastic improvements. However, it is important to use an integrated approach that considers both automation equipment and software systems. Furthermore, it is important that the approach considers the requirements today, as well as the potential requirements in the future. Solutions should allow firms to improve supply chain today, as well as prepare for the supply chain of tomorrow.