I recently came across several examples of requirements design documents which focused on the solution and assumed we're all aligned around the business justification. This is mostly common when all of us are already working on some project and there is a tendency of group thinking.

I personally got to make this mistake a few times.

But then I realized it will be a best practice to start off each design document with describing:

1. What is it we're trying to solve – and it's important not to jump to the point of why we're trying to solve it the way we are

2. How are we going to measure it

Let's take the common example of the space pen. During the work on the US space program, a need came for an anti gravity pen that will allow astronauts to write in space. A lot of investment was done…