This is not about why do we need a prototype. Or the opposite of Why don't we need a prototype. It's about why some of the projects that we did without a prototype/not even thinking about one...
Most of our projects (small scale IT/software development), did not require a prototype. Some were
RAD, some were developed using typical
waterfall methodology or
agile. For major projects prototypes were required. During a recent project meeting, I was challenged to explain why prototypes were required on some projects and not on others. ". . .[h]ow do you determine that you don't need a prototype?"
For each of those projects, what made us to not to create a prototype..? I am cracking my head... I could only think of following reasons (and I am not fully convinced):
- Client has no time for prototyping and needs accelerated development
- Requirements and process to be improved are Crystal clear
- Smalle scale projects that can be written within a day to 7 days or with max 2 weeks
- Some enhancements or modifications to an existing system
All of the above has to follow the basic project life cycle. Also for e.g. does a migration project (say from Java to C#) better off with a prototype of without (I am not asking specifically for migrations, but it could be one of the situations in real life)?