The  Tribunal held that there should be warranty provisioning policy based on scientific method and if such provisions were made on experience and historical trend and if working was robust, then question of reversal in subsequent years might not arise significantly. Tribunal held that Provision for warranty was not contingent lability as assessee had followed scientific method and had considered historical data to arrive at correct book profit as per provisions of section 115 JB.  (AY. 2002-03, 2003-04)