FUNDS MANAGEMENT (FM PB Availability Control)

BUDGET CONTROL, FUNDS MANAGEMENT (Budget Control Document 1700013859). The Activity Group is PAYROLL. Getting message that states the following:

Budget Consumption 122,733.14 USD (FM PB Availability Control) less than annual budget for document item 00001.

Can someone tell me what the threshold is? (i.e. 90% expended) and can this warning message be modified from the standard SAP message to better inform departments as to what is occurring. They have not run out of funds, but have reached a threshold that needs to be monitored.