When Harvard Business School professor Tom Eisenmann devised a programme based around case studies of business failure, he worried at first that immersing his MBA students in tales of defeat would depress them. He was pleasantly surprised, however, that it had the opposite and very galvanising effect. Failure, he says, provides great lessons for success. âItâs easier to remember all the things not to do rather than the things that you should. I think focusing on failure is a very powerful thing for entrepreneurs,â he tells The Irish Times. Harvard Business School is also an impressive start-up factory. Its alumni have founded 1,300 venture capital-backed start-ups since 2006. Nineteen of these have achieved unicorn status (over $1 billion valuation) over the last decade.