What is a Scrum Master, what are his tasks and how many teams can he support in parallel?
Facilitator for Product Owner and Development Team
The Scrum Master is a role in Scrum. As a facilitator, he tries to help the development team and the product owner – the other two roles Scrum defines – achieve goals together. As facilitator the Scrum Master is at the same time moderator, mediator and coach. His aim is to make work easier for colleagues and to promote collaboration. It is his responsibility to create a trusting, open working atmosphere. He promotes interaction and communication between colleagues. He represents a mindset that results from the values and principles of the Agile Manifesto. At the same time, he must be a precise observer and, for example, address unproductive behaviour. He thus serves both the product owner and the development team, but without being a servant. In business practice, a double function as Scrum Master and Product Owner or Developer should therefore be avoided in any case.
The tasks of the Scrum Master
A common misconception is that the Scrum Master “only” moderates the Scrum Meetings. He is responsible for the following tasks.
- He is in charge of the Scrum rules, organises the different events and is the guard of the timebox.
- He supports the product owner and the development team in sprint planning and selecting the backlog items from the product backlog to be implemented in the next sprint. Possibly he also moderates the Planning Poker
- He moderates the Daily Scrum, in which the development team exchanges information on completed and pending tasks on the way to the sprint goal. In some organisations he updates the taskboard.
- He takes care of the impediments that were discussed in the Daily Scrum.
- He moderates the Sprint Review and thus the presentation of the generated increment.
- And he leads the team’s reflection during the retrospective, which may also include feedback for his own work and where he also actively shares his observations.
If there is a Scrum of Scrums within the organisation, a Scrum Master takes care of the event and the exchange of participants – often in a rolling order.
The number of teams per Scrum Master
In development practice there are always questions about the number of teams that a Scrum Master can manage at the same time. In this discussion, an erroneous understanding of the role primarily becomes apparent, because even if the Scrum Master is responsible for adhering to the rules, he is not the manager of the team or teams. A facilitator does not decide; he promotes and supports.
The actual answers vary from one to a maximum of six teams. The number 6 results from a small calculation: one Scrum Master spends approximately 13 hours per 2-week sprint in team meetings. 13 hours x 6 teams / 8 working hours per day = 9.75 days that a Scrum Master would sit in team meetings during the 10 available working days. He had only 2 hours for necessary preparation and follow-up of meetings, for coaching, individual discussions or escalations. More teams do not work mathematically, less probably makes the most sense.
Scrum Master Certification
There are two recognised Scrum Master certificates:
- Certified Scrum Master (CSM), offered by the Scrum Alliance
- Professional Scrum Master (PSM), offered by Scrum.org
The main difference between CSM and PSM lies in the type of certification: CSM is based on a combination of training – conducted by a Certified Scrum Trainer (CST) or a Certified Enterprise Coach (CEC) – and a test. The PSM separates training and certification, so a Professional Scrum Master has passed a test but does not need to have attended an official training. Furthermore, a PSM training does not have to be conducted by a certified trainer.
Beyond CSM and PSM, both the Scrum Alliance and Scrum.org offer additional certifications. For the Scrum Alliance these are
- Advanced CSM (A-CSM),
- Certified Scrum Professional (CSP),
- Certified Team Coach (CTC),
- Certified Enterprise Coach (CEC) and
- Certified Scrum Trainer (CST).
And at Scrum.org these are in addition to the Professional Scrum Master I (PSM I),
- Professional Scrum Master II (PSM II),
- Professional Scrum Master III (PSM III), and
- PSM Trainer (PST).
Obviously the Scrum Alliance offers significantly more certificates than Scrum.org. In addition, the Scrum Alliance demands a recertification every 2 years. At Scrum.org this requirement does not exist.