what is more desirable positive or negative variance
The Project Management Institute, however, endorses the accepted convention that a negative variance is a bad thing, and a positive variance a good thing. A variance is the difference between the projected budget and the actual performance for a particular account. A negative variance means that the budgeted amount was greater than the actual amount spent. A positive variance means that the budgeted amount was less than the actual amount spent. Note there is some debate over whether a negative variance means an underrun or an overrun.