How to keep the predictability of your product delivery during periods of frequent absences?

Taking care of the predictability of delivery and team velocity in software development projects is quite challenging – especially with flu season, sick leaves and deadlines.
That is why we put much thought into this at Setapp and decided to introduce a +1 (“plus one”) concept to our clients & teams. We all are deeply satisfied with it. Why? Let me explain. …
What is the + 1 concept, and how does it improve the predictability of delivery?
A +1 concept assumes that an additional specialist extends the standard team size. Our goal is to keep the average velocity of a standard team size even if someone is absent. In particular, if all team members are present, someone from the team is not working on regular task development (is on a +1 or has a +1 role).
Significantly, +1 is not a permanent team member. It is a transitive role. Thanks to this, we have much more flexibility in managing the absences by simply assigning someone on a +1.
What is crucial here is that the person on a +1, if not absent, still attends all team events and is up-to-date with the project. It allows the team to react quickly, even when an unexpected absence occurs.
Finally, the decision on who and how long will be on a +1 is left to the team’s discretion.
How can you utilize these benefits of having a +1?
Please look at these three examples of situations we experienced when having a +1 was a blast for the PMs, POs, stakeholders, and the development team.
Situation 1: / Context: Sick-leaves or holiday season absences
+1 scenario:
A person absent due to disease, holidays, or other reasons is on a +1. This way, we have more flexibility in reacting to sudden sick leaves without affecting velocity and more stable iterations.
without + 1 scenario:
The development team must work with decreased capacity, thus losing pace, impacting the delivery schedule and overall predictability.
As a result, a + 1 concept helps to fill the gaps, so the team can safely deliver increments even in case of sudden or planned absences.
Situation 2: / Context: During the particular Sprint, we do not have a lot of tasks for the back-end developer. Instead, we have much work to do on the front and three available developers skilled in this area of expertise.
+1 scenario:
The back-end developer becomes a + 1, so the front-end tasks can move forward more quicker. The back-end developer can focus on self-development and energizing before the next Sprint while attending all the Scrum events.
without + 1 scenario:
We do not have that flexibility in arranging the work during the delivery cycle. The back-end developer waits or works with fewer tasks than the rest of the team. We have to deal with this disproportion. If more situations like this occur, the team’s performance might suffer.
As a result, with a + 1, we have more flexibility in planning the most optimal skill set needed to achieve each sprint’s goal. Thanks to the + 1 concept, we generally have a broader skillset and additional brainpower during activities that +1 attends.
Situation 3: / We have an eight weeks deadline, and more tasks have occurred than the team can manage in their capacity. We need to increase it to keep the deadline.
+1 scenario:
If we have a standard team size of four and a + 1, we can increase it temporarily to five team members delivering increments for eight weeks. After that, we can return to a standard team size of four and a + 1.
without + 1 scenario:
We must move the deadline or assign a new team member and proceed with project onboarding before this person starts the work. That is problematic and can quickly lead to further delays and bottlenecks.
As a result, a + 1 concept allows us to increase team size instantaneously – permanently or temporarily. The main benefit here is that + 1 attends all scrum events and does not need any onboarding or introduction to help deliver increments if needed.
The benefits of + 1 concept:
Stakeholders / PMs / POs
Iteration stability and predictability of delivery,
Ability to increase team size instantaneously – permanently or temporarily,
More effective problem-solving capabilities among the development team.
Development teams
Space for self-development,
Broader skill-set & additional brainpower,
Time to do long-horizon research.
However, the additional analysis discovered even more benefits of the concept.
What do you think about this +1 („plus one”) concept? It can be beneficial in many ways for both client and the team. Please share your thoughts with me; always happy to discuss them.