My sales dept would like to see a report with the customer due date along with the est ship date.  I looked in the file for SO Line Items and found the date stored in bkar.invl.asd.  I understand from another thread that the report is possible after invoicing in the on-time report, but we would like a listing before invoicing.  I was looking for a report to put this field into; the user defined detail report is bksooj1 and there is no corresponding t6 file in my list of reports to edit. Can I edit this bk file with the Tas Editor?  Am I on the right track or should I just do this in Access??

That's wha I though, Lorne, about both the report editing and the ASD being actual ship date.  However, when I went into maintain database, and looked for the field with my customer due date in it, on a Sales order that has not been shipped, it was in the ASD field.  In fact in the BKARINVL ( OPEN SALES ORDERS?)file there  are two date fields, esd and asd, both have dates in them, even though no lines have been shipped.

See this topic "Requested vs. Estimated Due Dates"  
The way I read it, ASD is being used for the dream date until invoiced, then dream date is stored in the SO tracking file (ISARHCHG or whatever). Then the ASD is used for the actual ship date in the SO history files.

Cyndee has it right and it was necessary to use an external file since we have committed not to change the underlying structure of the existing files.