I have already solved this problem.

I have solved this type of problem before.

My team has solved this type of problem before.

My company has solved this type of problem.

My profession or industry has solved this type of problem.

Science has solved this type of problem.

Science has not yet solved this type of problem.

The right kind of design process to use depends on the novelty of the problem at hand. The first case of 'I have already solved-' is a manufacturing process, where you simply have to replicate an existing design. At the other end is pure research, which happens on an uncertain schedule. Most software development problems lie somewhere in between. A good development process is tuned to handle the typical novelty of problems given to the team. And not what you wish that it were, but what it is.