SAP’s Warehouse Management (WM) module provides extensive reporting tools to track, monitor, and correct your warehouse operations. Warehouse process monitoring is both a strategic and tactical approach to more efficient, productive operations. Effective process monitoring provides visibility to data that facilitates efficient operations. Employing basic tools in SAP WM and coupling them with enhanced reporting enables you to increase the visibility of your data. This data is typically required to make informed decisions and achieve desired results.

Based on my experience, understanding and taking advantage of these standard tools for tracking and monitoring task progression improves the success of any Warehouse Management System (WMS) implementation. In this article, I’ll discuss one of the many monitoring tools available in SAP ERP Central Component (ECC), the picking wave monitor.

Improve Picking Efficiency with Wave Picks

Rather than pick one order at a time, you can promote more operational efficiency by grouping deliveries into wave picks that you can process at roughly the same time. Using wave picks, you can perform detailed planning for picking by creating work packages, which is accomplished through the create wave picks functionality. This function creates picking waves and defines them as groups in your SAP system. A group number is a grouping of individual outbound deliveries that you plan to pick at the same time.

Create Picking Waves

Follow menu path Logistics Execution Outbound Processes>Goods Issue for Outbound Delivery>Picking>Wave Picks>Create to create picking waves (Figure 1). This functionality allows you to select deliveries to be grouped together into a wave. You can create picking waves according to delivery time, shipment number, a combination of the shipment number and time, or via the outbound delivery monitor. I’ll describe these four methods in more detail.

Figure 1

Menu path to begin the create picking waves function

Method 1: Select deliveries according to delivery time. In this method, you can select deliveries to group together based on the individual delivery’s planned goods issue date and time, which is stored in the delivery header. You typically use this method if you do not use shipment numbers to group outbound deliveries.

Method 2: Select deliveries according to shipment number. This is a straightforward method in which you simply identify the shipment numbers you want to consolidate into a group. However, you must know the shipment numbers you plan to use because there are no other selection criteria. This method is commonly used to create groups since most organizations already group their deliveries into shipment numbers. You can have one shipment number correspond to one group number, or you can select multiple shipment numbers to relate to one group number.

Method 3: Select deliveries according to shipment number and time. This option is similar to method two, but it includes additional selection criteria such as the shipment start loading time and shipment end loading time. Both settings are already defined in the shipment. This method helps if you’ve already grouped your deliveries into shipments and pre-defined times for the start or end (cut-off) loading time. Using this method, you can select shipments with similar cut-off times for the start or end of loading, which allows you to schedule the required associated picking tasks backwards.

Method 4: Select deliveries via the outbound delivery monitor. This method is relevant for selecting individual deliveries that are not associated with a shipment number. The functionality is similar to method one, although it offers one key advantage — the user interface is through the outbound delivery monitor, which some end users find to be more user-friendly.

In many cases, you’ve already grouped deliveries that should be shipped at the same time using a shipment number in your SAP system. A common scenario is a group of deliveries to be loaded into a single shipping container or trailer. Say shipment number 1050 is an outbound shipment that should be loaded into a single trailer. The trailer has a departure time of 2:00 PM. Based on your organization’s normal processing times, you might plan to begin the trailer loading at 1:00 PM. This means your picking tasks must be completed by 12:30 PM to allow for quality checking and final packing. A normal load usually takes about one hour to pick, so picking must start no later than 11:30 AM. This process describes how you schedule backwards through wave picking. I’ll use this example to walk you through the wave picking process.

Shipment 1050 is comprised of three individual deliveries — 80000166, 80000168, and 80000169. You decide to create a wave pick for the 2:00 PM outbound load so that the picking tasks are completed together and on time. In this example, you already know the shipment number for which you plan to create a wave pick, so you elect to use method two (create wave picks according to shipment number).

The first step is to create a group number — also referred to as a wave number — which links the three deliveries in the shipment together. Follow menu path Logistics Execution>Outbound Processes>Goods Issue for Outbound Delivery>Picking>Wave Picks>Create>According to Shipment to generate the screen shown in Figure 2.

Figure 2

Create a wave pick for a specific shipment number

This transaction creates a group (wave) number for the shipment you are trying to pick. Enter the warehouse number and shipment number on this screen, then click on the execute icon to display the deliveries to be grouped together. Click on the save icon to generate the wave number. In this example, I created wave number 2000000015.

After you create the group number, you can then create the transfer orders (TOs), which are the picking tasks associated with this group. You could create the TOs individually by delivery as you normally do, even if you were not using wave picks. Alternately, you can create the TOs with reference to the group number. Again, this is no different than creating the TOs with reference to the delivery numbers. The same stock removal strategies and logic apply whether you use a picking wave or not.

Use the Picking Wave Monitor to Display Picking Progress

Access the picking wave monitor via menu path Logistics Execution>Outbound Process>Goods Issue for Outbound Delivery>Picking>Wave Picks>Monitor (Figure 3). You can track the processing status of the wave picks with the picking wave monitor, which displays outbound deliveries grouped by wave and the details of each group (e.g., the number of TOs, transfer line items, and transfer line item status. This becomes a valuable monitoring tool when you have multiple waves being picked in parallel. You can easily determine which individual picks are open and waiting to be picked. This becomes quite beneficial in the event that you have limited pick bin space and need to replenish between waves or every few waves.

Figure 3

Menu path to access the picking wave monitor

The picking wave monitor functionality crosses the Sales and Distribution (SD) and WM modules. As such, you’ll notice that the initial display screen shows information that is based on delivery item data points, but also includes shipment status and WM item status. The key data displayed on the initial screen includes:

• Individual delivery numbers contained within the wave or group number
  
  
• Ship-to party of each delivery
  
  
• Delivery header status

The delivery header status includes the following detailed statuses, as shown in Figure 4.

Figure 4

Picking Wave Monitor: List screen

• WM: Overall WM status based on the status of the TO line items
  
  
• PS: Packing status based on the status of the delivery line item
  
  
• TS: Transportation planning status based on the shipment status, if relevant
  
  
• GM: Goods movement status (post goods issue [PGI] status defines if the delivery has been shipped yet)
  
  
• BS: Billing status based on whether an invoice was created for the delivery

From a WM perspective, supervisors and team leads are typically most interested in the key data that contains the progress of the picking tasks. You can view this information by selecting a specific wave in Figure 4 and then clicking on the PickProgress button at the top of the screen. The Picking progress list screen automatically appears, as shown in Figure 5.

Figure 5

Picking progress list

The key feature of the picking wave monitor is its ability to graphically display the progress compared to picking at the TO line item level. The picking progress lists shows:

• How many total line items must be picked for the wave
  
  
• How many line items have been confirmed, indicating a completed pick
  
  
• How many line items are still open, signaling items remaining to be picked
  
  
• Percentage of picked lines vs. the total of picked lines. In other words, are you 60%, 70%, or 75% complete?
  
  
• The breakdown of line items by source storage type, including data on the physical location that picking items are coming from and whether or not multiple pick bins apply to a certain wave

Users typically focus on two main pieces of information — the number of picks by storage type to be completed and the number of picks by storage type that are already completed. In Figure 5, there are six picking tasks to be completed from storage type 200, as depicted in the StTy. field. Only two of the six pick tasks have been completed, so the graphical display shows a horizontal bar chart with one third green and two thirds red. The green bar represents the amount of completed picks, and the red bar signifies the amount of picks that have not been completed yet.

You can use the Picking progress list to quickly determine if any picks remain and what storage type the picks are coming from, and you can graphically display the current progress by storage type. If picking tasks are running behind schedule, the supervisor can promptly identify which zones or storage types are becoming a bottleneck. This information is especially useful for potentially sending idle resources to assist in the picking progress. It is also important when you are planning the replenishment of the picking bins. Standard SAP WM does not allow you to plan replenishment for waves that exist in the future. In WM, you must close out the picking wave you are currently processing before evaluating the pick bin’s stock level and deciding whether or not it should be replenished with reserve stock.

Additional Functions of the Picking Wave Monitor

In addition to tracking the processing status of wave picks, you can perform subsequent functions based on the documents associated with the wave (deliveries and TOs). You can use the picking wave monitor to:

Plan replenishment for fixed picking bins: In warehouses that use fixed picking bins, it is convenient to launch the “Create TRs for Replenishment” transaction from the monitor. As you execute picking waves throughout the day, inventory levels in pick bins will diminish and require replenishment. A warehouse supervisor who is monitoring wave progress will find it easy to initiate replenishment tasks directly from the monitor, which eliminates the need to back out of the monitor transaction and then navigate to the replenishment transaction.

Create TOs for the wave: As mentioned earlier, once the group number has been created, the next step to executing a wave is to create the associated TOs. Launching the TO create screen from the monitor provides the convenience of staying within a single cockpit while easily navigating to relevant and commonly used transactions.

Print/reprint TOs for the wave: This option is rarely used and is mostly for use in warehouses that use paper-based picking (using a printed TO instead of a mobile radio frequency transaction).

Confirm TOs for the wave: Most likely used in warehouses that use paper-based picking. Once the picking tasks have been completed, the user then returns to the work station to enter in the confirmations of the picks he or she has just completed.

Create shipments: In most cases, the shipment for a set of deliveries has been created prior to the wave picking process. However, if for some reason the outbound deliveries are not associated with a shipment but should be (example: deliveries to be loaded on a single trailer bound for a common destination), the user can jump to the create shipment transaction directly from the monitor.

Post Goods Issue: Once the deliveries within a wave have been fully picked and loaded, the shipping clerk can initiate the PGI movement transaction directly from the monitor. The PGI step releases inventory from the shipping plant and acknowledges that the goods have departed the facility.

Create billing documents: This function is rarely used from the picking wave monitor since most users are focused on warehouse execution rather than customer invoicing. However, it can be used in the event of an export shipment to generate a pro-forma invoice for customs declaration purposes.

To access the above functions from within the picking wave monitor transaction, go to Picking Wave>Subsequent Functions.

The picking wave monitor is a very useful tool for shipping department end users. It provides the capability to create and monitor wave picks for outbound shipping orders, which increases the efficiency of warehouse operators. In addition, it provides a single cockpit for executing WM-related shipping tasks, which appeals to warehouse supervisors and shift leads.