Overcoming Challenges with Automated WMS

Previously, we have published articles providing information about different elements of warehouse automation.

• Introduction to Warehouse Management Systems (WMS)
• History of Warehouse Management Systems (WMS)
• Investigation into Popular WMS Software
• Characteristics of Highly Automated WMS Systems

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Warehouse processes are not simple. They involve careful process management and maintenance to ensure operations run reliably and efficiently. However, even with best practices and excellent management in place, it is very difficult to keep things running well for the long term. Sometimes this happens also with high levels of warehouse automation. The next sections cover some of the most common challenges and issues that warehouse operations could face and how WMS solutions and industrial automation are helping overcome them.

 

Figure 1. WMS solutions help solve many warehousing challenges. Image used courtesy of MultiChannelMerchant

 

Excess Redundancy

Redundancy can be a good thing in control automation, especially when safety is concerned, but not so much in warehouse operations. In this context, redundancy occurs when the same operation is performed two or more times unnecessarily. Warehouse process redundancy typically occurs when workflows are not well understood or organized. The larger the warehouse facility, the more prone it is to unintended redundancy due to the increased number of process steps and larger volumes of inventory to work with.

One example of redundancy is when forklift operators make multiple unnecessary trips across a warehouse. In a manual system, drivers are given sheets with pick instructions which they fulfill one at a time. Instead, with a WMS in place, this can be eliminated. The WMS can preemptively calculate optimized routes to fulfill an entire order or shipment. In some cases, they can suggest consolidation tasks, reducing the total number of trips to take.

Highly automated WMS that count on laser-guided vehicles (LGV) and/or automated storage and retrieval systems (ASRS) take this a step further. Not only are there no humans involved in the task execution, but there are further dynamic optimizations that the WMS can initiate. For example, in a system with multiple LGVs, the WMS can dynamically reallocate tasks based on real-time system changes. Let’s say an LGV is headed to point A to pick a product. Suddenly, another LGV, which is closer to point A, becomes available because it just finished another task. The WMS can swap the task and assign it to the second LGV. The first LGV then becomes available to perform another task that is near to it, and thus takes a shorter time.

 

Figure 2. Large warehouses are more prone to encounter redundancy. Image used courtesy of SupplyChain247

 

A WMS does not need to be fully automated to provide benefits in process optimization. Other examples of technologies that reduce or eliminate redundancy are barcode scanners and GUI screens positioned at strategic locations.

Inventory Issues

Maintaining inventory accuracy is extremely important. A mismatched inventory level can lead to several problems, some of them severe. Production orders could be incomplete due to lacking raw materials and shipments of finished goods could be delayed due to miscounts. Keeping accurate records of inventory is another task that is extremely difficult in purely manual systems. Paper records and spreadsheets no longer work well in the modern and increasingly dynamic industry, even in small operations.

A WMS greatly reduces the incidences of inventory issues because they work with real-time information that is much less prone to human error. Another important advantage of a WMS over a manual process is the use of graphical user interfaces. In warehouse management, counting with visual aids of the warehouse that give the precise location of the product is very helpful. Instead of relying on tables and operators memorizing location numbers, a WMS GUI can provide a map of the facility, highlighting relevant locations.

 

Figure 3. Modern WMS software is equipped with advanced 3D graphics. Image used courtesy of SmartWMS

 

The fact that the information is real-time makes inventory counts more efficient. In many highly automated warehouses, manual inventory counts are performed sparsely.

Storage Utilization

Maintaining sustainable levels of warehouse saturation is important to avoid operations shutdowns. This means it is critical to keep a proper balance of what is stored and at what levels. Too much of one product could lead to the inability to store the minimum levels of another. Improper warehouse levels, while they cannot be called human error necessarily, are caused by the inability of manual processes to keep up with rapid or changing production rates.

Warehouse saturation is one of the most important KPIs that a WMS should be tracking. It is in the core functionalities of a WMS to do everything possible to monitor, consolidate, and optimize quantities and storage space. The WMS immediately knows the best location to use for a given product based on current conditions. Low-volume products can be kept in more remote locations while high rotation products can be kept closer to shipping docks, for instance.

 

Figure 4. Warehouse space utilization is another task optimized by a WMS. Image used courtesy of ImpactWMS

 

Highly automated WMS takes this a step further by automatically performing warehouse consolidation tasks. In what is also known as housekeeping, robots can perform point-to-point movements to help saturation levels. For example, if there is only one unit left of a certain product that is occupying an entire large storage location, a robot can be instructed by the WMS to pick that product and move it to another smaller location, with a traceable location change. This way, the large storage location will be cleared and can be used for another type of product with a larger volume available.

Cross-docking is another important function enabled by a WMS and automation. It consists of moving items straight from production or in-bound receiving straight out to shipping, skipping warehousing entirely. This greatly optimizes systems. The WMS can do this because it knows the business rules that enable cross-docking, and it also knows the real-time conditions of what is being produced.

Summary

The huge task of warehouse automation is naturally prone to challenges including redundancy, inventory issues, and utilization of storage space. They cannot be eliminated, but with proper planning and a practical strategy, those challenges and effects can be mitigated.