First, it's right to expect a mix of new dev with support/maintenance tasks, and you're not alone. Second, if you're overwhelmed by support work, then I'd ask why?
We run scrum with 2 week sprint cadence and mix new dev with support/maintenance. The allocation differs based on season and events. Any support tickets we do don't count towards velocity and are mixed in with story point tasks and other maintenance/debt tasks. We track velocity as points delivered to a client, which helps with estimation for delivery of products / features to clients. This velocity is an average, and that's when the numbers work in your favor as "all estimates are wrong."
In a scenario where velocity is constantly decreased by support/maintenance/bugs, that tells a story, either of quality of work done previously, impatient management, or lack of discipline by the team. If you can't go a sprint without having to put out fires, that's indicative of a system that should be mitigated on a larger scale than continually applying bandaids, otherwise you'll constantly be bit.
In my mind, your choices are: change your cadence/strategy, change your values/philosophy, change management style, change your budget/velocity, invest heavily now to replace troubled systems, invest in man power to put out fires, or simply stay the course with a shift in perspective.
We run scrum with 2 week sprint cadence and mix new dev with support/maintenance. The allocation differs based on season and events. Any support tickets we do don't count towards velocity and are mixed in with story point tasks and other maintenance/debt tasks. We track velocity as points delivered to a client, which helps with estimation for delivery of products / features to clients. This velocity is an average, and that's when the numbers work in your favor as "all estimates are wrong."
In a scenario where velocity is constantly decreased by support/maintenance/bugs, that tells a story, either of quality of work done previously, impatient management, or lack of discipline by the team. If you can't go a sprint without having to put out fires, that's indicative of a system that should be mitigated on a larger scale than continually applying bandaids, otherwise you'll constantly be bit.
In my mind, your choices are: change your cadence/strategy, change your values/philosophy, change management style, change your budget/velocity, invest heavily now to replace troubled systems, invest in man power to put out fires, or simply stay the course with a shift in perspective.
Only you can choose.