Across my writings and comments on project management, I very frequently stress the need for good communications, developing relationships with stakeholders, and tailoring communications to your audience. One of the challenges for project managers is to communicate a complex plan. Showing a detailed MS Project plan with several hundred lines spreading over months of effort, to key stakeholders, is generally is not helpful.
One good way to explain the project to senior stakeholders and sponsors is to produce a plan on a page which gives them a view of the key chunks of work on the project, and usually has a timeline which is only shows months or even quarters of time. The plan on a page can be tailored to different audiences to stress the elements of the project they are most interested in.
Unfortunately, I increasingly see project managers using the plan on a page as the only project plan. There is a real difference between the plan on a page as a communication device, and the plan on a page being used as the project plan.
As a communication device the plan on a page can be excellent. But that is about all. You cannot estimate resources, assess the impact of dependencies or work out critical paths with a plan on a page. More fundamentally for me, the biggest problem with the plan on a page is that it indicates that the project manager really has not thought through the project.
Developing a project plan is essential in estimating resources, timelines, risks and so on. But it is not just the output from planning that is important, it is the process itself. Developing a detailed project plan forces the project manager to think about and understand the project. If you have not developed your own detailed plan, I do not think you really understand your project.
Of course, there are sometimes small projects of limited complexity that can fit a fully detailed plan on a page. But using a plan on a page as the only project plan, for an initiative of any complexity, is either laziness or incompetence.