Have Want                 Desire Result After FIFO Effect Account Period Earned Adjusted Purge Expire Redeem Available Purge Expire Redeem Available A 200801         1,000                -                  -                  -                  -           1,000                 1,000                              -   A 200802         1,000                -              500                -              500         1,000                    500                    500                            -   A 200803         1,000            500                -                  -                  -           2,500           1,500                          -   A 200804         1,000                -              250                -           2,500            750           1,000                          -   A 200805         1,000            500            250                -                  -           2,000           1,500                          -   A 200806         1,000                -                  -                  -              750         2,250           1,000                          -   A 200807         1,000         1,000                -                  -                  -           4,250           2,000                          -   A 200808         1,000                -                  -              250         1,000         4,000           1,000                          -   A 200809         1,000                -                  -                  -                  -           5,000               250                       750 A 200810         1,000                -                  -                  -           2,500         3,500                  -                     1,000 A 200811         1,000                -                  -                  -                  -           4,500                  -                     1,000 A 200812         1,000         1,000            500            250         1,000         4,750                         2,000 Total        12,000         3,000         1,500            500         8,250         4,750                 1,500                    500       8,250                   4,750     Problem:- I want to create First in First Out (FIFO) calculation in above example. Means All points Earned Under (Earned and Adjusted) column throughout period will be my Starting balance.   Now Anytime when Account has either Purge or Expire or Redeem points in future period It should deduct from prior Points earned under Earned and Adjusted  variable.   For Example, Total earned points at the end of period 200812 will be 15,000 (12,00 from Earn + 3000 from Adjusted column) And 10,250 Debited points (1,500 from Purge, 500 from Expire and 8250 from Redeem column). Means Account has 4,750 points left. (15,000 – 10,250= 4,750).   However, I need 10,250 points distributed from lower to higher period using FIFO. Means 1,500 points from Purge column should be deducted from the balance of 2,000 points (Earned +Adjusted column) for period 200801 and 200802. After 1500 points deduction we still have balance of 500 which will be used to deduct 500 Expire points. Now we don’t have any balance left for period 200802. So for redeemed points of 8250 should start deducting from period 200803 onwards. It should deduct the points from earned bucket (Earned +Adjusted) until became zero.   Please refer attached file for soft copy. Ultimately My desire output is in green on the right side.   I tried to explain in detail as much as possible but please feel free to revert back if you need any more additional information.   I would really appreciate if you can help me ASAP. ... View more