This really depends on everything from the number of people on the approval committee, they number of organizations supplying source material, the length and number of the final productions, when can shooting begin, what is the launch or conference date it is needed for, and the complexity of the design and approach to the subject matter. We have shot in the morning, edited in the afternoon and had the final video in the client's hands that evening. We have had approvals and client schedules take over a year. Let's say we are producing an eight minute corporate message, with C to C supplying scripting, interviews with 4 different people and additional location shooting, some graphic work like a logo animation and two maps with statistics, a professional narrator, licensed library music, and an approval committee of four who are updated on initial production choices. A fair time from Yes lets do it to final DVD copies may be about 2 months.
In some cases your deadline of two weeks may determine certain production choices to ensure the deadline is met.