Identification of a problem that needs to be solved.
• Inventing a solution to the problem, which works.
• Developing a prototype or being able to demonstrate the invention to prove how it works.
• Filing a patent application to protect the invention so that it can be disclosed to other people.
• Arranging the manufacturing and marketing of the invention either through one’s own company or through licensing.
• Each stage requires its own particular expertise and resources. It is essential that the early stages are satisfactorily completed before moving on. Experience shows that taking short cuts does not pay.
For example, it is hard to get investors or potential licensees to appreciate the benefits of a particular invention if the prototype is very crude and does not work properly. Similarly there is little point in filing a patent application until one is satisfied that the invention can be shown to work.
There can be some overlap between the last two stages however. If it is possible to make some progress with manufacturing and marketing without compromising the patent position, then one should do this. As mentioned elsewhere, very often the later one files the patent application the better.