Slow BAPI Performance

Question

We're having some issues regarding BAPI performance.
- BAPI_PO_CHANGE - Deleting all items
- BAPI_SALESORDER_CHANGE - Setting a single custom field
We're getting a runtime of between 5 and 30 minutes for doing a relatively minor change.
For example we have a PO were we're deleting all the items.
ls_poitem-po_item = 00010.
ls_poitem-delete_ind = 'L'.
append ls_poitem to lt_poitem.
ls_poitem-po_item = 00020.
append ls_poitem to lt_poitem.
ls_poitem-po_item = 00030.
append ls_poitem to lt_poitem.
ls_poitemx-po_item = 00010.
ls_poitemx-delete_ind = 'X'.
append ls_poitemx to lt_poitemx.
ls_poitemx-po_item = 00020.
append ls_poitemx to lt_poitemx.
ls_poitemx-po_item = 00030.
append ls_poitemx to lt_poitemx.
call function 'BAPI_PO_CHANGE'
  exporting
    purchaseorder = '1234567890'
  tables
    return        = lt_return
    poitem        = lt_poitem
    poitemx       = lt_poitemx.
if lt_return has no errors.
  bapi_transaction_commit.
endif.
In DEV, the bapi takes around 10 seconds to run, and the commit about 15 seconds. In PRD where there are lots of items, possibly BOMs it is taking between 5 and 30 minutes. The program is running in the day and during the night where hardly anything is going on in the system.
I've done a runtime analysis over the function and the majority of the time seems to be taken dealing with conditions and there are no user exits that are affecting the BAPI. 20% Database, 80% ABAP.
Can anyone explain why the bapis may be taking such a long time to run or whether there is something else I should be looking at?
I have noticed in st02 (buffers) there is a huge amount of swaps occurring, specifically with the import/export buffers. ~ 1 million per day! Would something like this affect anything?
Many Thanks

Answer 1

@Diwakar - I've debugged the bapi (painful!) and there was no noticeable enhancements or exits being called out that appeared to be slow.
@Manu - One of the first things I checked. The program here is just a single PO with no loops.
@Yuri - It does look like it is condition related. The items I used in Dev were not BOMs, but I know in Prd they are used. Here are some results:
Sorted by "No."
No.       Gross =      Net Gross (%) Net (%) Call                                                                                Program Name                     Type No. Filte
8.053     44.950     44.920       0,4     0,4  Perform XKOMV_AUFBAUEN_PRUEFEN                                                         SAPLV61A
6.441     17.595  =  17.595       0,1     0,1  Perform CONDITION_UPDATE_KAWRT                                                         SAPLV61A
6.441     17.335  =  17.335       0,1     0,1  Perform CONDITION_UPDATE_KWERT                                                         SAPLV61A
5.235    480.833    109.490       3,8     0,9  Perform XKOMV_KWERT_ERMITTELN                                                          SAPLV61A
5.208    164.660     34.644       1,3     0,3  Perform KONDITIONSBASIS_ERMITTELN                                                      SAPLV61A
5.077     22.825  =  22.825       0,2     0,2  Perform XKOMV_KKURS_ERMITTELN                                                          SAPLV61A
4.821    407.084  = 407.084       3,2     3,2  Perform XKOMV_KAWRT_ERMITTELN                                                          SAPLV61A
4.092     42.332  =  42.332       0,3     0,3  Perform XKOMV_KBETR_FROM_KWERT                                                         SAPLV61A
4.087     26.921  =  26.921       0,2     0,2  Perform XKOMV_KBETR_ERMITTELN                                                          SAPLV61A
4.079    211.423    147.126       1,7     1,2  Perform XKOMV_FUELLEN_OHNE_KONP                                                        SAPLV61A
4.079      6.374  =   6.374       0,0     0,0  Perform USEREXIT_XKOMV_FUELLEN_O_KONP                                                  SAPLV61A
4.074     12.628     12.598       0,1     0,1  Perform XKOMV_ERGAENZEN_MANUELLE                                                       SAPLV61A
2.387     30.438  =  30.438       0,2     0,2  Perform XKOMV_UEBERTRAGEN_VORBEREITEN                                                  SAPLV61A
2.385     11.630  =  11.630       0,1     0,1  Perform FIXIEREN_KOPFKOND_POSITION                                                     SAPLV61A
1.488      6.066  =   6.066       0,0     0,0  Perform(Ext) KOBED_002                                                                 SAPLV61A
1.188      3.394  =   3.394       0,0     0,0  Perform(Ext) FRM_KONDI_WERT_080                                                        SAPLV61A
  990      9.082  =   9.082       0,1     0,1  Call M. CL_BADI_CACHE_HANDLER=>GET_IMPLEMENTATION                                      BADI_SD_SALES_ITEM============CP
  968      5.325  =   5.325       0,0     0,0  Select Single TCK32                                                                    SAPL0K01                         DB     OpenS
  594      1.633  =   1.633       0,0     0,0  Perform(Ext) FRM_KOND_BASIS_004                                                        SAPLV61A
  575      2.284  =   2.284       0,0     0,0  Perform STATUS_VERKNUEPFEN                                                             SAPLV45P
  483     10.372  =  10.372       0,1     0,1  Perform EXECUTE_CHECK                                                                  SAPLCKDI
  462      7.632  =   7.632       0,1     0,1  Perform CONVERSION_IN2EX                                                               SAPLSDH4
  367      2.957  =   2.957       0,0     0,0  Perform HIDE_INFO_FUELLEN                                                              SAPLSLS_LORD_DFLOW
  340    205.332      8.647       1,6     0,1  Call M. CL_EXITHANDLER=>GET_CLASS_NAME_BY_INTERFACE                                    CL_EXITHANDLER================CP
  340     12.255      6.789       0,1     0,1  Call Func. SXV_ADD_PREFIX                                                              SAPLSEXV
  340     15.421      3.166       0,1     0,0  Call Func. SXV_GET_CLIF_BY_NAME                                                        CL_EXITHANDLER================CP
  340      5.466  =   5.466       0,0     0,0  Call Func. SX_NAME_SPACE_SPLIT                                                         SAPLSEXV
  335      4.363  =   4.363       0,0     0,0  Select Single SXS_ATTR                                                                 CL_EXITHANDLER================CP DB     OpenS
  318     12.836      2.092       0,1     0,0  Perform CULLX_EVAL_CND                                                                 SAPLCULL