Explanation
The communications management plan is a component of the project management plan that describes how project communications will be planned, structured, implemented, and monitored for effectiveness1. It also defines the communication methods, formats, frequency, and stakeholders for each type of communication2. Since the company's new communication system will introduce a new format and frequency of communication for the executive board, the project manager should update the communications management plan to reflect this change and ensure that the stakeholders' information needs are met3. References:
1: A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Seventh Edition, Chapter 4, Section 4.1.3.3
2: A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Seventh Edition, Chapter 4, Section 4.2.3.1
3: A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Seventh Edition, Chapter 4, Section 4.3.3.2