Tools Availbility Check

Hi Gurus,

Actually i need to use tools in my PM order for my work. I thing PRT is the option.

For that i have crated one PRT and put formula usage value , but when i m going to use that prt in order as prt , system shoing error , Division by zero in formula. which formula should i use and here i should put it.

so that once any tools is used in one order alrady , should not availble for another order for same period.