Using Wave Management in Warehousing

Waves are groupings of warehouse request items (that is typically, the items of outbound delivery orders) that control warehouse activities, like picking. These groupings are then processed together in subsequent processes, for example, the transfer of all warehouse request items assigned to a wave to warehouse task creation.

With SAP S/4HANA Cloud Public Edition, warehouse management you can combine warehouse request items for outbound deliveries into waves, based on criteria such as activity area, route, or product. You can also split warehouse request items from warehouse requests for outbound deliveries into waves. You then pick or process warehouse request items in one wave at roughly the same time, to improve your warehouse efficiency.

The system allows for automatic wave creation. This is achievable by scheduling wave creation as a background job using wave templates. Alternatively you can create and maintain waves manually with an additional note in the Warehouse Monitor.

You can automate the assignment of warehouse request items to waves. For automatic wave assignment, you have to maintain the following settings:

• You have created wave templates
• You have defined selection criteria for warehouse request items in the scheduling job for waves
• You have scheduled the background job that creates waves automatically in the background

In Warehousing, the following steps are carried out by the system when waves are created automatically:

1. The background job for automatic wave creation is triggered at the scheduled time
2. The system selects the existing open warehouse requests that match the selection criteria in the job definition
3. The system tried to determine a valid wave template for each item or split item in the relevant warehouse requests
4. The system determines planed completion, wave completion and lock time based on the template option used.
5. The system check whether a wave already exists for this wave template option.
   • If no corresponding wave exists, the system creates a new wave with the wave template option that was determined and assigns the item to this wave.
   • If a corresponding wave already exists, the system assigns the item or split item to this wave. If an exception occurs, for example, if the wave exceeds the wave capacity, the system creates a new wave using the same wave template option.
   • If a corresponding wave already exists and has already been released, SAP EWM creates a new wave with the same wave template option. The system then assigns the item to this wave.

A wave template is a schema that defines the attributes of all the waves that are based on it. It serves as the infrastructure for automatic wave assignment. Wave templates enable the same wave attributes to be reused for different warehouse request items that comply with the same conditions. You can also use wave templates to create waves manually, or, in the case of automatic wave assignment, to assign items or split items from the warehouse requests to existing waves that are based on the wave templates.

The following attributes are available for wave templates:

• Release method with the possible values Automatic, Immediate and Manual.
• Wave type: enables specific monitoring in the Warehouse Management Monitor
• Wave category: can be used as filter criteria for warehouse order creation rules
• Control for bin denial: This allows you to choose between the following option:
  • You can leave an item in a wave, or, in other words, release it again later.
  • You can remove an item from a wave, or, in other words, reassign the item.
  • You can have the system immediately create a warehouse task with an alternative source bin.

A wave template may consist of one or more wave template options.

The following attributes are available for wave template options:

• Data for date and time:
  • Cutoff time: The time up to which you can add items to the wave
  • Cutoff days: A set number of days before the wave completion date. The system uses the cutoff days to calculate the cutoff date.
  • Release time: The time by which the wave must be released
  • Release days: A set number of days before the wave completion date. The system uses the cutoff days to calculate the release date.
  • Picking completion time: The time by which you must have completed picking for the wave
  • Picking completion days: A set number of days before the wave completion date. The system uses the cutoff days to calculate the picking completion date.
  • Packing completion time: The time by which you must have completed packing for the wave
  • Packing completion days: A set number of days before the wave completion date. The system uses the cutoff days to calculate the packing completion date.
  • Staging completion time: The time by which you must have completed material staging for the wave
  • Staging completion days: A set number of days before the wave completion date. The system uses the cutoff days to calculate the staging completion date.
  • Wave completion time: The planned time by which all processing operations for the wave are to be completed
• Calendar for defining workdays
• Staging area group for the created warehouse tasks
• Staging area for the created warehouse tasks
• Mode that applies to all warehouse tasks that are created when the wave is released

  For more information, see Mode.

• Capacity profile for defining capacity limits

With the wave creation scheduling app, you're able to schedule and monitor wave creation jobs. This app is perfect if you have tasks that you frequently perform at a specific time. It lightens your workload by running these jobs seamlessly in the background. You're able to schedule wave creation regularly.

You can us the app to do the following:

• Schedule a wave creation job based on a template
• Work with personalized job templates
• Monitor wave creation jobs
• Display job results
• Copy a job
• Cancel a job

To schedule wave creation jobs, select a job template, define the description, start date, start time, and recurrence of the job, and enter job-specific selection criteria and parameters.

You can create and personalize a job template, save the personalized job template for later use, and share personalized templates.

You can process the waves in various ways in the Warehouse Monitor app to control your warehouse activities.

You can process waves in the following ways:

• Lock or unlock

  You can lock a wave that has the status I (Initial, wave is created). As a result, the status of the wave is changed to H (Locked, wave is locked). You can't release locked waves.

  When you unlock a wave, the system resets the status of the wave to I.

• Merge

  You can merge as many waves as you want, if the following conditions are met:

  • The waves haven't been released yet. They have the status I or H.
  • All the waves have the same status, either I or H.
• Simulate
  • You can simulate one or more selected waves before releasing them, using the monitor methods Simulate Waves and Simulate Single Waves. By simulating waves, you can preview the upcoming wave releases and identify potential problems in advance, for example, missing stock.
  • After the wave has been simulated, you can perform other actions from the Wave Simulation: Results screen, such as viewing warehouse order creation information or viewing the wave simulation log using the monitor method Display Simulation Log. You can also manually release waves from this screen.
• Release
  • Waves are used to create warehouse orders and warehouse tasks. Waves can be released using one of the following release methods:
    • Automatic (One Batch Job)—The system creates a job that automatically releases waves on the release day and at the release time.
    • Immediate —When a wave is created, the system releases this wave immediately.
    • Manual—You can manually release a wave at any time. When manually releasing waves, you can also release locked waves. In this case, the system sets the status of the created warehouse orders to Locked. As a result, these warehouse orders are temporarily locked for further processing.

    You can set the release method as an attribute in the wave template using the Maintain Wave Templates app.

  • When a wave is released to create warehouse tasks, the system copies the staging area and the mode of the wave to the warehouse tasks.
  • You can release waves multiple times. For example, you release a wave, but the system can only create some of the required warehouse tasks since there isn't enough stock; you can release the wave again later when more stock is available.
  • You can view the log using the monitor method Display Release Log.
• Split

  You can select a warehouse request item and remove it (that is, split it) from the current wave. The system creates a copy of the wave and assigns the warehouse request item to the copy.

• Delete

  When the system deletes a wave, it removes the assignment of all the warehouse request items from the wave. The system deletes a wave completely, which means that you can no longer archive it.

For a graphical overview on the business process of the scope item Wave Management in Warehousing (6NH), refer to the SAP Signavio Process Navigator as described in the lesson The Impact of Warehouse Management.

The following SAP S/4HANA Cloud Public Edition business role is used for this scenario:

• Warehouse Clerk (EWM)

Process Step	User Role	SAP Fiori App
Schedule Background Job for Wave Generation	Warehouse Clerk (EWM)	Schedule Wave Creation
Simulate Wave (Optional)		Warehouse Monitor
Release Wave
Display Wave Release Log and Warehouse Task (Optional)

The Roles and Apps Used in the Scenario Wave Management in Warehousing (6NH) figure shows the roles and SAP Fiori apps involved in the process. All wave-related activities are carried out by the warehouse clerk in this case.