On competion and forecasting

I'm often asked to develop a financial model for a product candidate in development. One of the many challenges with this exercise is properly forecasting future competition and market sharing. I start by asking a number of questions:

1. Current commercialized Products
a. What are the projections for these products?
b. Will any lose patent protection in the forecast period?
c. If so, will that cause payers to drive a shift towards a particular generic?
d. Can a generic + a drug delivery system = a superior product?

2. Pipeline
a. Which candidates have a clear, well-trodden, "me too" development path, and why?
b. Which do not, and why?
c. Which candidates have strong financial backing?
d. Of those that do not, would they be good licensing/acquisition targets for a well-capitalized competitor in the therapeutic area?

This is just the tip of the iceberg. As with many things in life, assembling a solid forecast is not as simple as it looks.