Schedules are an important part of a continuous improvement culture. Daily schedules are used for communication and coordination as well as to highlight problems and improvement activity.
For example, many teams start the day with scheduled time to get the work area checked out and ready to go. They also likely schedule a standup meeting at the start of the day to resolve any issues that are uncovered and to communicate daily goals. Time to organize and clean the work area (5S) is often allocated at the end of the work day.
Leaders have scheduled times to update daily management boards. Materials teams often schedule specific collection times for kanban cards.
These schedules are extremely important because with very little excess in either time or materials, falling behind creates big problems. If something is on the schedule, especially if other people are involved, it is imperative to deliver any requirements on time.
In addition, because there is so little waste in a Lean organization, there is very little spare capacity. Meeting schedules become even more important. The agenda should be well-planned, and should take only the minimal time necessary.
While all of the above listed schedules increase in a continuous improvement culture, there is a schedule that should be discarded in most cases. Production schedules tend to be less effective than pull signals. That is not to say you should not have production targets or make forecasts. What it means is that you only produce when there is a demand from the downstream process, not when the clock says to produce.