I work on a lot of small, agile software projects without huge up-front requirements; just ideas that I flesh out over time. Generally, development follows these stages:
- Prototype (couple of days)
- Figure out 80% of the features and put them in the backlog
- Develop the product. Add stuff as you go along.
So there's a huge spike of work added, and then small steps of scope growth regularly.
What I like is that I can change direction fast. What I don't like is that I cannot gauge the rough size of a project before I start working.
What I'm looking for is some process or equation that will help me. "Generally, you add 50% to your project scope after the major estimation part. So factor that in."
How can I gauge the rough size of a project before I start working?