Review what a project is Before you start creating projects that link to other projects, consider what a project is—specifically, where it begins and where it ends.
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A project is an endeavor that is both temporary and unique. It is temporary because it has a beginning, middle, and end, such as constructing a building or designing a new manufacturing process.
A project is unique because it involves doing something that hasn't been done before; that is, it does not represent an ongoing process, such as manufacturing metal ingots on a daily basis. Similarly, a project to create a specific building is unique because that specific building hasn't been built before.
When you link one project to another by creating dependencies between tasks in those projects, you aren't necessarily combining two projects into one. You are facilitating the management of two separate projects.
For example, your corporation's manufacturing environment may dictate that a process in one project depends on the scheduling of a process step from another project, such as the attachment of wings for an airplane being dependent upon a separate process in another facility that builds the wings. Perhaps other tasks in the other projects are also beyond your control.
Create a dependency between tasks in different projects When you have a task that relies on or drives a task in another project, you can create a task dependency to link the tasks in different projects.
Change the dependency between tasks in different projects You can change the link type of an external dependency (external dependency: A relationship in which the start or finish date of a task depends on a task in another project.) from the default (finish-to-start) to start-to-start, finish-to-finish, or start-to-finish.
Enter lead or lag time for dependencies between projects As you can with task dependencies in a single project, you can enter lead time (lead time: An overlap between tasks that have a dependency. For example, if a task can start when its predecessor is half-finished, you can specify a finish-to-start dependency with a lead time of 50 percent for its successor [has a negative lag value].) to overlap tasks or lag time (lag time: A delay between tasks that have a dependency. For example, if you need a two-day delay between the finish of one task and the start of another, you can establish a finish-to-start dependency and specify a two-day lag time [has a positive value].) to delay a successor (successor: A task that cannot start or finish until another task starts or finishes.) task for external dependencies.
Review and update externally linked tasks When you make changes that affect externally linked tasks, you can update them with the click of a button. Or when changes in those tasks affect your project, you can update your project file with data from the external tasks. You can show or hide external predecessors, external successors, or both, to see only the tasks you want.
Delete dependencies between tasks If a task no longer depends on a task in another project plan, you can delete the dependency.