An agile project is about 45% complete, and most team members work in silos and lack understanding of each other’s work. What most likely caused this communication breakdown?

The daily standup, or daily scrum, is a key agile ceremony designed to foster team communication, synchronize activities, and identify impediments. If team members work in silos and lack understanding of each other's work, it strongly suggests that this frequent, short meeting, intended for quick updates and coordination, is not happening consistently or effectively. While irregular status reports (a traditional project management tool) or inconsistent sprint reviews (focused on stakeholder feedback and product increment) can impact communication, they are less directly tied to the day-to-day, intra-team understanding of individual tasks and dependencies. A communications management plan is important for overall project communication strategy but doesn't directly address the immediate, operational communication breakdown among team members in an agile context as effectively as consistent daily standups.