Scaling Scrum is an ongoing hot topic in the Agile space. For a while the most common answer to the question was scrum of scrums. It's a sensible approach, and it works... up to a point, and then... maybe not so much.
Over the past few years new options have emerged. Scaled Agile Framework (SAFe) has gained a lot of attention over the past few years (as well as heated debates), but it is not the only option available.
Since 2005 Bas Vodde (of Odd-e) and Craig Larman have been working on applying apply Agile and Scrum to very large and multisite product development. The result of this collaboration is Large Scale Scrum (LeSS), a framework that is designed to allow you to take the practices of “One-Team Scrum” and scale it up. One of the great things about this approach is that if you are already working with Scrum at the team level, a lot of the work practices are maintained, so you may encounter less dissonance than you’d experience from introducing an array of new practices and workflows. The idea is to allow room for coordinating more complex efforts while still keeping things as simple as possible.
LeSS offers two different approaches for scaling up with Scrum. If you are working with up to eight teams of not more than eight people per team, you would use LeSS. But if you need something larger, LeSS Huge has been used with efforts that involve as many as 2,500 people, all working on a single product. To date, LeSS has been used by product companies, project based companies and by companies that want to develop products internally.
If you are curious about LeSS, you can check out my podcast interview with Bas Vodde.
And if you want to know more about how it has been applied by organizations like Alcatel Lucent, Bank of America, Nokia, JP Morgan Chase, and others, the LeSS.works website has a number of case studies available here.