Hi Sandeep,
A dehydrated orchestration or message means that it is temporarily stopped until a condition is triggered to allow it to resume processing, so this does not mean that an error occurred (hence the absence of entries in the Application log when you checked the Event Viewer). Dehydration is different from Suspended status, which will indicate an error has occurred and will require manual intervention to either resume or discard the transaction.
In your SAP port, in the Transport Advanced Options tab, you most likely have the Retry Count set to a number above 0, so if your message did not get sent successfully the first time, it will be in a dehydrated state and wait to be resent.
You should investigate the reason why your message(s) are not getting through the SAP port. Does this have something to do with the way you configured your SAP port or the way things are set up on the SAP side that are not in sync with BizTalk? A SAP administrator can also help you troubleshoot this issue…
Daniel.