Timing diagram

The timing diagram is a tool for tracking progress (delays and offsets) used in project management. It informs at all times about the degree of respect of the milestones of the project.

The timing diagram (or 45° curve) is a graph having two axes: the axis of abscissa corresponds to the dates of updating of milestones, and the ordinate axis the projected dates milestones.

Each point on the graph represents the expected date of completion of a milestone (Y) as estimated at a given point in the project (X). This chart thus retains the memory of the announcement of the projected dates of the milestones of a project. That’s why it can detect shifts in a project..

The curve at 45 ° is in fact the line Y = X, and corresponds to events whose estimated date of realization or completion (Y) and the day when it is revised (X) are identical (that the milestone be achieved / completed or not).


Graphical interpretation



The milestone 1 corresponds to the ideal case without rescheduling or delay, gives a simple right.

Milestone 2 is the case where there was a delay of 15 days (September 29th instead of September 14th). The curve slides over the 45 ° to the closing of the milestone.

Milestone 3 shows the case where there was a rescheduling (following the delay on milestone 2)

Milestone 4 shows the case of 2 successive replanizations at 2 month intervals.