HP CEO Meg Whitman makes the whole company follow the advice in this book

Hewlett-Packard has over 300,000 employees. That's bigger than the entire population of Des Moines, Iowa ... by about 100,000 people.

How do you maneuver and lead such a huge team?

Answer: you make all the managers read the same strategy book and follow that books' advice.

For Whitman at HP, that book is "Playing to Win: How Strategy Really Works" by A.G. Lafley, chairman and CEO of Procter & Gamble, who retired from the company in 2010 and then came back in 2013.

Whitman famously began her career at P&G in Cincinnati in 1979, where she immediately took on the establishment. She helped the company end its practice of hampering women's careers by refusing to let them travel alone.

Whitman was asked about using the book at HP on the quarterly earnings conference call.

She explained:

The entire company has organized around "Playing to Win" which is a book written by A.G. Lafley and a colleague of his.

Listen, there are many ways to deploy strategy in companies. This is one I found to be particularly helpful because organizations have a lot of trouble making decisions, particularly at our scale.

So this notion of where to play, what countries, what market segments, what products, and where not to play because we can't do it profitably, has been a very good discipline. ...

And then once you determine where you're going to play, how to win. That is through a combination of where you are going to excel versus competitors.

It's actually been a really good common framework that we can apply across HP. It's easily understandable and actually forces the tough trade-offs.