[Reebz]

As much as agile is shouted from the rooftops for engineering and design, many businesses run in waterfall.

The reality is that budgeting and roadmapping is roughly an annual process. At that time scale and with sufficient people scale, management will need to illustrate how they will be spending millions of dollars and the sequence of activities.

Gantt charts are often the defacto communication method because people from many skills backgrounds easily understand them.