Timeline charts presents events and time periods on a chronological scale. They are used in project management to visualize project milestones and upper level phases, and show project progress.
"Within the framework of project management, a milestone is an event that receives special attention. It is often put at the end of a stage to mark the completion of a work package or phase. Milestones can be put before the end of a phase so that corrective actions can be taken, if problems arise, and the deliverable can be completed on time.
In addition to signaling the completion of a key deliverable, a milestone may also signify an important decision or the derivation of a critical piece of information, which outlines or affects the future of a project. In this sense, a milestone not only signifies distance traveled (key stages in a project) but also indicates direction of travel since key decisions made at milestones may alter the route through the project plan." [Milestone (project management). Wikipedia]
This timeline diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Timeline Diagrams solution from the Management area of ConceptDraw Solution Park.