New Delhi, Oct. 15 -- When you buy into a business, you want to know what you are really buying. Is it a one-trick pony that lives and dies by a single customer? Or is it a sturdy workhorse that can pull steady earnings through all kinds of weather?

In the case of Cochin Shipyard Ltd (CSL), that question goes to the heart of what makes a company truly durable.

For years, CSL built some of the Indian Navy's most complex ships-aircraft carriers, patrol boats, and anti-submarine vessels. That made for impressive headlines, but it also made CSL's fortunes depend heavily on government contracts.

At one point, almost Rs.9 out of every Rs.10 in its order book came from defence. Reliable, yes. But also limiting. After all, a company tied too t...