I read that Scrum meetings should be less than 15 minutes long. Is this how long they usually are, or do they depend on the size of the development team? Must every team member speak in these?
Is this how long they usually are, or do they depend on the size of the development team?
No. In my experience, they're either <10 minutes for a manageable team or like 30 minutes because the team is too large or there's nobody (good) in charge. Once you get over 10 minutes, people get antsy and stop listening.
Must every team member speak in these?
Yes. If they didn't do anything worth speaking about, they shouldn't be in the scrum - either because they belong on another team (stop wasting their time), or because they need to be fired (stop wasting your time).
The Scrum meetings should mainly involve
- What is the progress from the last meeting?
- What do you plan to do next?
- Do you see any blockers?
The actual time depends on the team size and should be short and quick. This is mainly a technique in agile world where you want to dynamically assess the situation and take decisions and also increase the transparency and better communication.
Your team is probably too big. Various sources, Mountain Goat Software among them, recommend doing team(s) of teams (Scrum of Scrums). This is analogous to the pizza rule that Amazon uses. The core principle here is to reduce the number of connections between people so that communication is less complex.
Fixing this would effectively require that you figure out how to break up the big team into smaller teams and have the authority or ability to persuade the authority to adopt this method.