As per the given formulas of schedule variance and cost variance. The schedule variance if is positive then you are ahead of schedule and vice versa. For the cost variance positive the project is under budget and for negative it is over budget. This formulas depend upon the the budget if they are equally distributed at every phase of the project. But there is a possibility that the initial phase for eg. Buying materials costs more at the start of project but cost low in the manufacturing of the device. So according to that the initial phase if we spent more and work done is left as the manufacturing is still to be coverd. This means that you can be over budget at the initial phase but it is possible that you can be on budget when the project is to be completed or complete. So how do you decide by the measurement of the EV, SV and CV that you are calculating at any point of project is same in reality after the project is completed?