Allowing the appeal of the assessee the Tribunal held that Trial production was different from commercial production and benefit of exemption provision was allowable from date of commercial production.  When the assessee company itself has not claimed exemption for AY 2000-01, incubatory period, cannot be considered as production period merely on the basis of token invoice issued for trial verification of its cost. Even otherwise, the letter issued by the assessee company dated 30.04.2000 to Assistant Director, STPI, Noida intimating date of commencement for production of sale in global market as 30.04.2000 has not been disputed by the Revenue rather entire assessment has been made on the basis of token invoice dated 31.03.2000 issued for trial verification by the assessee company. Followed  CIT v. Nestor Pharmaceuticals Ltd (2010) 231 CTR 337 (Delhi) (HC) (AY. 2010-11)