Last month, the British food and clothing retailer, Marks & Spencer, released a 5-year progress report on their sustainable retailing strategy, Plan A. (Slogan: “Because There Is No Plan B.”) The document, which was released at the same time as their annual corporate responsibility report, sets out the lessons M&S has learned since the inception of the strategy. To be honest, when I opened it, I was expecting just another report: nice photos and interesting anecdotes, but not much in the way of usable insights that could be applied elsewhere. I was wrong. Unlike many similar documents published by other companies, M&S have made a concerted effort to distil and share lessons on how to roll out an ambitious program to reconfigure a value chain across a large, national retailer. It’s a great read.