SAP EWM offers two ways of scheduling route departure times, which can be configured for different combinations of warehouse number, document type and document category:

• Backward scheduling
• Forward scheduling

This setting is made in IMG SPRO:

Extended Warehouse Management - Goods Issue Process - Outbound Delivery - Route Determination - Define Scheduling Within Route Determination:

With backward scheduling, SAP EWM uses the planned order date and time (TDELIVERY PLAN) to determine the route departure date and time.

With forward scheduling, SAP EWM analyses the planned goods issue date and time (EGOODSISSUE PLAN) of every order item and takes the latest date and time as the result.

The route departure date and time determined by one of the methods above is written into the order dates as the type TOUTYARD_PLAN and, under certain conditions, as TDELIVERY_PLAN.

When backward scheduling is used, conflicts between planned dates can arise – for example, the yard departure date may end up in the past, or earlier than the planned loading date the system determined. SAP EWM has additional settings for controlling the behaviour in such cases.

For instance, you can specify which dates the planned date of departure from the warehouse (referred to below as the route date) is compared with:

• Planned Date Usage: Picking, Loading, Goods Issue – in this case SAP EWM checks whether the route date falls earlier than the planned completion dates for picking, loading or goods issue.
• Planned Date Usage: Picking, Loading – SAP EWM compares the route date with the completion dates for picking and loading
• Planned Date Usage: Picking – compares it only with the picking completion date
• No Usage Planned Date – with this setting SAP EWM does not compare the route date with any other dates
• Usage Dates According to User Configuration – in this case SAP EWM compares it only with the dates listed under «Date/Time Types»

In addition to these settings you can specify whether the route date is to be compared with the current date:

• Date Today Is Not a Turnaround Point for Reverse Scheduling – SAP EWM does not compare it with the current date, so a route date in the past is allowed in this case.
• 1 Date Today Is a Turnaround Point for Reverse Scheduling – the opposite: SAP EWM compares the route date with the current date

And finally you can define what SAP EWM should actually do if the route date is earlier than the dates it was compared with:

• Error Message: Result Is Not Valid – if there is a date conflict, the route is not determined automatically.
• 1 Warning Message: No Reversal of Scheduling, Result Not Valid - if there is a date conflict, the route is not determined automatically. The route departure date and time is not changed, so it may be earlier than the date and time of some other date in the delivery. In addition the system issues a warning message.
• 2 No Message: No Reversal of Scheduling - Result Is Valid - if there is a date conflict, the route is still determined automatically. The route departure date and time is not changed, so it may be earlier than the date and time of some other date in the delivery. On top of that the system issues no warning messages about the date conflict at all.
• 3 Reversal of Scheduling in Forward Scheduling – if there is a date conflict, SAP EWM performs forward scheduling using the current date and time of departure from the warehouse.

It is also worth pointing out that if the route uses a route departure calendar, that calendar takes precedence and overrides the route departure date and time.