Surely an equally and always applicable profit share scheme.....
a) Remove the 12 month limit. When the target is reached the applicable share is awarded whether it takes 8 months, 12 months or 15 months.
b) Change it to a percentage scheme over 12 months. If we make the target then 100% of the applicable share is awarded. If we fall short by 10% then 90% is awarded........
If the figures are currently being massaged to award nothing then with the above we would (a) be awarded eventually and fully or (b) be awarded something regularly/annually.