Requisitions in SAP
-------------------

Some notes to describe the requisition data in SAP. 

There has been a request to store requisition data in the
warehouse, and to have the ability to examine dates of release
and conversion to POs.

Data in SAP
-----------

Two tables hold requisition information: 

           EBAN   -  requisition items
           EBKN   -  requisition account distribution

These tables are relatively small (~38,000 records each) 
and so can be brought oiver with full extracts, at least
to start with.

Dates
-----

The dates add a a little wrinkle. There is no simple 'release
date' (the EBAN release date field means something other than
MIT's concept of release date).

In order to get the release date we have to examine change logs
and determine when a certain field (the EBAN release indicator) changed.

We also need to bring over table T161S which contains extra information
concerning the meaning of release indicator.

So an incremental extract (I think) will be needed for the requisition 
change logs. This could be a single extract file from two SAP tables,
CDHDR (Change Log Hdr) and CDPOS (Change Log Detail).

CDHDR holds general information about a change (who made the change, when
it was made etc.) and CDPOS holds more detailed information - what field
was changed, the old & new values etc.

Release Status
--------------

In order to get a release status for a req item, the logic will be 
something like this:

   If the req item's release indicator is null, the item is deemed released.

   If the release indicator is not null, must use the indicator to look
   at T161S. If the column T161S-FRBST is 'X' then the req is released, 
   otherwise it is not released.

Release Date
------------

Similar to above but a bit more involved.

  If the req item's release indicator is null, the release date is the
  same as the req date (i.e. the req was automatically deemed released
  as soon as it was created).

  If the release indicator is not null, and the req was determined not
  to be released after looking at T161S (see above) then the release
  date is null. 

  If the release indicator is not null, and the req was determined 
  to be released after looking at T161S (see above) then we must look
  at the change log information:
  
      By looking at the changes in release indicator ( FRGKZ) for this req 
      and seeing when it changed from a 'not released' value (get this
      from T161S) to a 'release' value (from T161S), can determine the 
      relase date and also the person who effected the release.

Full Req Release Status & Date
------------------------------

One more thing - the above determination of release status and date 
applies to requisition items. The requisition as a whole is not considered
'released' and ready for PO conversion until all the items have been released. 

And the release date of the whole req presumably will be the release date
of the last of its items to be released.

Conversion Status & Date.
-------------------------

This may be easier. There is a 'processing status' on EBAN (STATU/BANST) 
which indicates whether or not PO has been created. Also there is a PO
number field which isn't filled in until the PO created. 

There is also a purchase order date, which could be used to determine
date of conversion. Alternatively, the change logs could be examined
to see on what date the processing status changed or the PO number was 
filled in. In this way, the person doing the conversion could also be
determined.