The ScrumMaster is a key element of the Scrum teams that need such a role for facilitating their work. In his book “Scrum Shortcuts without Cutting Corners”, Ilan Goldstein discusses the question if a ScrumMaster can be member of multiple Scrum teams.
Many in the Scrum community will strongly argue that the ScrumMaster role is significant enough to justify a “one team = one ScrumMaster” configuration. I support this argument, and Shortcut 26 highlights plenty of conclusive reasons demonstrating why being a ScrumMaster is absolutely a full-time role. That being said, it helps to remain open minded. I, for one, have acted as ScrumMaster on up to three teams at the same time, which, perhaps not ideal, can still work effectively assuming that the teams in question are well on their way to a mature state of self-organization. Let’s explore this juggling act a little further.
First, brand-new Scrum teams require one full-time ScrumMaster – no question about it. These fresh teams require significant levels of education, guidance, assistance, and most of all, constant inspection and adaptation. Taking on more than one brand-new Scrum team is not at all realistic.
Maturing teams that are settling into Scrum successfully, without systemic impediments (such as ugly politics or similar issues), and who are trending positively on the continuous improvement scale can potentially manage with a ScrumMaster working across two different Scrum teams.
Finally, elite, mature Scrum teams that are truly self-organizing, where improvements are more about fine-tuning, can arguably get by with a ScrumMaster working across three similar Scrum teams
Reference: “Scrum Shortcuts without Cutting Corners: Agile Tactics, Tools & Tips”, Ilan Goldstein, Addison-Wesley
The maturity scale used by Ilan Goldstein to define how many teams a ScruMaster can help makes sense if you believe in the concept of the self-organizing teams. It is natural that teams that are transitioning to Agile from a traditional project management approach need more coaching to adapt to the new practices. It is very important that an experienced ScrumMaster help them to avoid falling in a mechanical Agile attitude, that is they just follow Agile “rules” without understanding their goals and putting in place a continuous improvement and adaptation process.