How you prevent an employee posting to a fully consumed funding source in OTL

Summary:

Hi Team,

Our client would be using cloud projects, grants and time and labor. we would be creating sponsored projects with awards and funding source.

we have added contract number and funding source field on the time card. The client wants to know if we can prevent an employee posting to a fully consumed funding source on the OTL side. Example lets say for Project A, we have Award X and 2 funding source A1 and A2. We have allocated 20000$ for funding source A1 and 10000$ for funding source A2.

The client wants to know if OTL can stop the employee from entering time in funding source A1 if the cost goes above 20000$.