Visio Timelines

Visio Timelines are an excellent way of quickly communicating a Serial development cycle. Below is an example for a single PWB assembly:

However, these can get rather difficult to read when the project is more complex. Below is an example of a single card assembly, simple chassis, and single software image, with several spins of the hardware and software, and test. Pretty busy.

The above example is about the limit of this mechanism. Visio has a way of linking together multiple serial processes, and displaying them together - but then they are not truly serial, since they have parallel dependencies. In my opinion, anything approaching the complexity of the project above probably should use Gantt charts.