You might occasionally find it necessary to share information between project plans, especially when you're working with multiple projects or adapting information from an old, finished project to a new project you're beginning to plan. There are a variety of situations in which you might need to share information, as follows:
A task in one project might depend on the start or finish of a task in another project.
Task or resource information or specific fields might need to be copied or moved from one project to another.
Customized project elements, such as views, ...