Any tips on modeling sales rep ramping; meaning modeling the increasing
productivity over time, until a rep hits 'full' productivity?

Some assumptions might include:

first 90 days of hi 25% productivity, where 100% productivity = monthly
run rate of 100% performance to quota

91-180 days = 50% productivity

etc.

The issue is, forecasting sales over time as reps enter the sales force.
Looking for a more accurate gauge than simple 'add a rep, get full
productivity' assumption.

Thanks,

R.