A communication matrix is a tool that helps you organize and document your communication plan. It specifies what, when, how, who, and why of each communication activity in your project. For example, you can use a communication matrix to define the purpose, content, frequency, format, channel, sender, receiver, and feedback mechanism of each communication deliverable, such as status reports, meetings, presentations, newsletters, surveys, and so on. A communication schedule is a tool that helps you plan and execute your communication activities according to a timeline. It shows when each communication activity will occur, how long it will take, and what resources and dependencies are involved. By developing a communication matrix and schedule, you can ensure that your communication plan is comprehensive, realistic, and manageable.