Communication plan is necessary for project management
For all big projects which are designed for few months or years communication plan is necessary. One can not manage project effectively in absense of a proper communication plan. That is why most of the project managers love communication plan.
It gives a guideline how to handle various departments at once in a single project. Communication plan gives an entire course of action following which a business can easily reach its target audience at the right time and can take best out of them.