Actual life and remaining life should be same after revalaution or seperately shown on form

Hi Guys

if life initially is 50 years and after three years revaluation is made and life is estimated by the valuer as 40 years. The system shows life after revaluation as 37 years (40-3). It should be shown as 40 year (being the estimated remaining useful life of the asset). Although the calculation at back end is done correctly i.e. working is done at 40 years.

Kindly help me in this regards.

Regards

Qadeer Ahmed