For goals-based investing first you might categorize goals/needs into Primary, Secondary and Aspirational and assign them required probabilities of success.  For example, a primary goal of having $5M in 10-years to retire may need to have a 95% probability of success.  Lets say they have $2.5M now, they’d need a 7.18% annual rate of return, but how can I design a portfolio that mathematically has a 95% chance of success in 10 years?

Would I use the Value at Risk framework, ER(p)-1.65(Standard deviation)?  I’m not sure how to use that over a 10-year time frame.  I guess I’m asking, how do I determine what combination of expected return and standard deviation will give me a 95% probability of success over a given time period?  Is Monte Carlo the only way to do this?

Thank you for any help and feedback!