Loading an Unloading date of Freight Unit

Hi,

I am a novice in SAP TM and need experts guidance in this query,

Loading and the Unloading date of FU is having the past date of the acceptable start date for some of the FU.

I agree the pick up and devliery date will be taken from the DTR document to the FU. Based on the dates in the DTR, the acceptable and  requested start and end date will be calculated.

But here, I would like to know how the Loading and Unloading date are populated in the FU document and further flow to the departure and arrival date to the FOR.

Because of this inconsistency in few shipment , planned ship date becomes the shipment start date and hence becomes incorrect as per the customer schedule.

Thanks for your much help.

Regards,

Premalatha. S