My case is related to that question, I chose NOC 5241 without having the education requirements (Art or design). I have an information systems degree. Graphic and web design jobs hardly require you to have such qualifications. A portfolio of work is usually enough proof, together with how well you do in your interview. I worked for 2 reputable design agencies. Do you think there will be any issues? All my letters match the tasks and duties of that NOC. I just don't have a formal diploma or anything of that sort.The simple answer is NO. But there has to be some connection. If you closely see the NOC, each NOC has a required education requirement. If you do not have that education requirement, you will have to prove how do you qualify for that. Eg. if your bachelors is in engineering and over the years you have become the VP of your company, you deal with the administration and for administration you need a MBA, you can show that this was by virtue of your experience.
Since your question is too abstract, this is the best I can answer. Henceforth, please give context to your questions.
I'm sure you already know about this page: http://www.cic.gc.ca/english/resources/tools/perm/econ/fsw/minimum.asp
under Minimum work experience requirement, it says:
"Note: The applicant does not need to demonstrate that they meet the “employment requirements” listed in the NOC occupational description."
Thanks as usual for your help!