Technology firm iGATE Patni expects nearly 25 per cent of its overall revenue to come from the product engineering services (PES) business in two-three years. "We expect almost 25 per cent of our total revenues to come from the PES business in two-three years. Currently, about 15 per cent of the revenues accrue from PES business," said Executive Vice-President and Head of PES Satish Joshi.