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 Automatic Wave Assignment

Purpose

You can automate the assignment of warehouse request items to waves .

Extended Warehouse Management (EWM) uses the condition technique to determine wave templates. This enables EWM to determine which wave template corresponds to certain data from the header, item, or split item of a warehouse request. For more information, see Wave .

Prerequisites

You have created wave templates. To do so, on the SAP Easy Access screen, choose Extended Warehouse ManagementWork SchedulingWave Management/SCWM/WAVETMP – Maintain Wave Templates.

In Customizing, you have defined the conditions for wave template determination.

Here you have defined the following:

Key or combination of fields that EWM uses to determine wave templates

Access sequence

Condition types and their assignment to access sequences

Determination procedures

Assignment of determination procedures to document types

Condition maintenance groups

For more information, see the Implementation Guide (IMG) for Extended Warehouse Management ( EWM ) under Goods Issue ProcessWave ManagementWave Template Determination

You have created condition records that connect the conditions and wave templates. To do so, on the SAP Easy Access screen, choose Extended Warehouse ManagementWork SchedulingWave Management/SCWM/WDGCM – Maintain Conditions for Determining Wave Templates.

You have set the Automatic Wave Creation indicator for the warehouse process type in which the warehouse request item is found.

For more information, see the IMG for EWM under Cross-Process SettingsWarehouse TaskDefine Warehouse Process Type

Process

EWM performs automatic wave assignment as follows:

EWM has multiple warehouse request items.

EWM uses the condition technique to determine valid wave templates for the delivery for each warehouse request item.

For each wave template, EWM determines whether the wave to be created lies within the period of time between the actual point in time and the planned completion time for the warehouse request item. The actual point in time is the current system date and system time. Depending on whether a relevant wave exists already, and whether it has already been released, EWM uses this wave or creates a new one.

Detailed Process

After you or EWM have created or changed a warehouse request, EWM creates a Post Processing Framework action (PPF action).

You start to process the PPF action. On the SAP Easy Access screen, choose Extended Warehouse ManagementWork SchedulingPrintSPPFP - Display and Process PPF Actions.

Depending on your settings for the condition technique, EWM determines one or more valid wave templates for each item or split item in the warehouse request.

EWM reads the attribute data for each wave template.

EWM determines the following times:

EWM determines the planned completion time of the warehouse request item and the wave completion time for each item or split item in a warehouse request that EWM has not yet assigned to a wave.

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Planned completion time for warehouse request item

For stock removal, EWM uses the planned date and the planned time for Departure from Yard .

If these dates are not available, EWM uses the dates for the goods issue start for outbound deliveries.

In the case of internal stock transfers or posting change deliveries, EWM uses the dates from the date/time category Warehouse Activities End Date/Time .

Wave completion time

EWM determines the date and time for wave completion for each wave template option.

If the planned completion time for the warehouse request item is before the wave completion time specified in the template option, EWM sets the wave completion date to that of the day before the planned completion date for the warehouse request item.

If the planned completion time of the warehouse request item is after the wave completion time or is the same as the wave completion time specified in the wave template option, EWM sets the wave completion date to the planned completion date of the warehouse request item.

EWM changes only the wave completion date on the basis of the situations described.

The following figure shows the complete situation:

In the first case, the planned completion time of the warehouse request item is 13:00 on day 2. The planned wave completion time is 15:00 on day 2. As such, the planned completion time of the warehouse request item occursbeforethe wave completion time that you specified in the wave template option. EWM schedules the wave to be created with the wave completion date of the day before the planned completion date of the warehouse request item, in other words, 15:00 on day 1.

In the second case, the planned completion time of the warehouse request item is 15:00 on day 1. The planned wave completion time is 13:00 on day 1. As such, the planned completion time of the warehouse request item occursafterthe wave completion time that you specified in the wave template option. EWM schedules the wave to be created with the wave completion date on the same day as the planned completion date of the warehouse request item, in other words, 13:00 on day 1.

EWM calculates the dates for a wave template option in accordance with the calendar that you have specified in the wave template.

Lock time

EWM calculates the lock date, lock time, release date, and release time using the date and time of the wave completion.

If any of these times are before the actual point in time, the wave template option is invalid.

EWM attempts to find a valid wave template.

If the dates and times for the lock and the release are after the actual point in time, the wave template option is valid and EWM uses all the dates in the wave template.

If the dates and times for the lock and the release are before the actual point in time, the wave template option is not valid and EWM does not use the wave template option with this date.

If EWM does not find a valid wave template option in the past for an item or split item in a warehouse request, EWM executes the following (“In the past” refers to the planned completion time of the warehouse request item, but the determination of a valid wave template still occurs after the actual point in time.):

EWM determines the date and time for the wave completion.

If the planned completion time of the warehouse request item is either before the wave completion time or is the same as the wave completion time, EWM sets the wave completion date to the day after the planned completion date.

If the planned completion time of the warehouse request item is after the wave completion time, EWM sets the wave completion date to the planned completion date of the warehouse request item.

EWM then determines the date and time for wave completion for each wave template option (see step 5).

If EWM does not find a valid wave template, it adds a day to the wave completion date. EWM repeats the calculation for the wave completion time and the lock time.

EWM determines the sequence for the best wave template and wave template option. To do this, EWM sorts the wave templates that were determined according to the level number and counter number in the determination procedure of the condition technique and according to the access number of the access sequence. Within the same level number, counter number and access number, EWM sorts the wave templates and wave template options that were determined by the wave completion time that is closest to the planned completion time of the warehouse request item. This means that the wave template option with the wave completion time closest to the planned completion time is first within a block of possible waves for the same level number, counter number and access number.

EWM transfers the results, in other words, all valid wave templates and wave template options for each item or split item in a warehouse request to Business Add-In (BAdI) /SCWM/EX_WAVE_PLAN, method CHANGE_WAVES.

EWM assigns a wave or wave template to each item or split item in a warehouse request. EWM checks whether a wave already exists for this wave template option.

If no corresponding wave exists, EWM creates a new wave with the wave template option that was determined. EWM assigns the item or split item in the warehouse request to this wave.

If an exception occurs, the wave template option is invalid. For example, the wave exceeds the wave capacity. EWM then attempts to create a corresponding wave using the next wave template option.

If a corresponding wave exists already, EWM assigns the item or split item in the warehouse request to this wave.

If an exception occurs, the wave template option is invalid. For example, the wave exceeds the wave capacity. EWM then attempts to create a corresponding wave using the next wave template option.

If a corresponding wave exists already and has been released, EWM attempts to create a corresponding wave with the next wave template option. EWM then assigns the item or split item in the warehouse request to this wave.

You can permit exceptions by setting the Wave Assignment Also Possible After Wave Release indicator. This enables you to assign another warehouse request item to a wave that has already been released, in other words, the wave template option is valid in this instance.

Example

The following figure provides an example of how EWM creates a wave:

In the first case, wave template option C does not lie within the period between the current point in time and the planned completion date of the warehouse request item. It is therefore invalid. Wave template options A and B lie within the period between the actual point in time and the planned completion date of the warehouse request item. Wave template option B is closest to the planned completion date of the warehouse request item, and is therefore the best wave template option.

In the second case, all the wave template options lie outside the period between the actual point in time and the planned completion date of the warehouse request item. They are therefore all invalid. EWM first determines the wave template option that is the closest to the planned completion of the warehouse request item, in other words, wave template option B is the best wave template option.