The waterfall model originated in manufacturing and construction where changes are costly and investment in design of the production line is often much less than potential loss if the actual production fails. It is based on idea that planning and design costs are much lower than those used in the actual production.
## Software development life-cycle (SDLC)
The software waterfall model often uses some variation of following phases:
Requirements specification (Requirements Analysis) resulting in Requirements Document
Software design resulting in Software Design (SD) document
I tend to discuss things openly and often with my colleagues. Before I start Google-ing for some solution, before I start banging my head around some problem or before I start designing an application or some new feature, I tend to consult my coworkers and see whether their experiences might help. At other times, I see someone's commit and became curious about the reasons for the way that someone implemented the solution or I might see the better way to do something. The list goes on and on... In all those cases, I prefer to get up, pair with someone and work it out. Ideally, that someone is sitting next to me. Those I communicate with do not seem to mind. Quite contrary. Unless they are very good at pretending, they act in a similar fashion and seem to do the same with me. All in all, there is a lot of communication going on, great ideas floating around and, ultimately, some kind of shared knowledge and ownership is established. I truly believe that those discussions are what makes us all better professionals.