On his last official working day in Delhi Metro, E Sreedharan was busy helping Chennai Metro learn key lessons.Counted as one the best technocrat managers, the country has had, the 79-year old Sreedharan will hand over the reins of Delhi Metro Rail Corporation (DMRC), to his successor and colleague Mangu Singh, on Saturday evening. Singh oversaw the implementation of high-speed Airport Express line.Sreedharan, who retires from the organisation after 14 years, joined DMRC as the Managing Director in November 1997. This was after successfully implementing the Konkan Railway project in difficult Western Ghats terrain. A year later, in 1998, the construction work for Delhi Metro started, and the first section of Delhi Metro was ready in 2002. Today, the Delhi Metro network is spread over 190 km in the National Capital Region (NCR).Many of India’s government agencies—saddled with missing deadlines while working within the Government framework—have looked for him or for somebody “like him”. Sreedharan plans to spend his post-retirement days in his native state, Kerala, but should not be surprised if he is hounded by invitations to lead similar projects around the country, given his reputation to cut to the chase and through the red tape.