The dabbawalas of Mumbai carry lunch boxes from homes to offices. They are often said to hold a Six Sigma rating. The claim goes back to a Forbes article of 1998. Ragunath Medge, the head of their association, told Forbes they made a mistake “almost never, maybe once every two months.” The reporter turned this into one mistake in 8 million deliveries.
The author, Subrata Chakravarty, later said: “Forbes never certified the dabbawalas as being a six-sigma organization.” He added: “six-sigma is a process, not a statistic.”
In 2010, Harvard Business School added a case study on them, The Dabbawala System: On-Time Delivery, Every Time.