Delphi-TVS Technologies, which commenced production of common rail system in 2009 has reached milestone production of over three million common rail systems at its manufacturing facility in Oragadam, about 45 kms from here. "We continue to expand the production capacity in common rail systems at the plant. We expect to invest about Rs 150 crore every year over the next two-three years..." Delphi Technologies President A Viswanathan told reporters. The company caters to all sections of the diesel engine market including passenger cars, commercial vehicles, tractors, construction equipment and industrial engines.