Any casual viewer of the BBC programme, Dragons Den will be aware of how easy it is for weaknesses or gaps to be identified. Depending upon the purpose of the plan, this may, or may not, prove to be critical. It is often easier to recognise such weaknesses and gaps, and be prepared to deal with them, either by noting them in the plan itself, or having appropriate answers available should the need arise.
No doubt there would be a lot work to do to do a plan like this. You would need to figure out how to put it all together, do all the calculations, do a lot of what if's, etc.. And I'm sure one of the biggest things would be, would you actually take the time to do something like this or even have the time to do it? You could pay someone to do it but that would probably cost you a lot. Plus if you did that, most likely it would require a lot of back and forth work to get it just like you wanted it which would be even more expensive. But even then, would you spend the money to do it? There is a better way. If you would like to develop a nice plan like this for yourself and give yourself a good shot at making your life better, then find a planning software that does it all for you.