Why do some research centres and university department publish a multi-year future strategic plan? I noticed that a few research centres and university departments provide a multi-year strategic plan document on their websites.
For example, IIT (Italian Institute of Technology) and Stanford Computer Science Department.

The plan usually describes the main goals and purpose of the institution, both in science and in research management.

Why do they actually do it?

Is it just a way professors and researchers try to predict their future?
Or is it a solid way to show their future scientific directions to the world?

What happens if the strategic plan is not respected by scientists and events during the following years?

And why so many institutes actually don't do it?
Another reason may be funding at a large scale. Governments sometimes have plans to strengthen the research in a certain area (ex. biosciences). By making an institution-wide plan, you can make a very strong case for the funding agency and possibly secure a large amount of money. The time scale is also important. If you have money guaranteed for seven years, you can buy expensive equipment and hire experts knowing that you will not have to let them go after a year, for example.

In the particular case of Stanford I imagine their main target is private investment. The aim of the plan is then showing off a strong commitment to their objectives.