"I ran two scenerios through Financial Engines.  One, I in put in my current portfolio, in the other I moved 20-25% of my current portfolio into fixed income investments.  The likelihood that I would meet my financial goal didn't change, but the range of results narrowed considerably."

DOING SCENERIOS?

Well, I do alot more than just 2 ( more like a dozen) and I also am able to Ask my Alama M. /  U of W at Madison,Wi.,  Prof. and he gives to his  students for their Analysis/Opinions.( Runs their Endowment and other Financial Courses ) which love Actual Ports to work on...( Ck out Yours? )

Then When I get the One I like the best? I also subtract another 10% from it's APY's/Rtns/Income etc..for my Balanced and Bond Funds ( -20% for Equity Funds & Stocks )   Eg: Bal/Bond Port, past 10 yr apy = 10% -10% = 9%

Why? Margin of error, (Murphy's Law, another 2000-2002 Bear series or wose .)             I never plan on any Funds/Investments to even do what a past 10 yr APY'S have been, for the future and thus forces me to add more to my Conservative investments and thus Less in my Higher Risk/Rtn one's..

Increase more $ needed for ? = Health Care costs..

I add 20% a yr to  My Estimates vs Medicare, Supp Plans, Deductibles, etc..

Figuring Lump sum income to retire...? 

Don't know about everyone else, but My Income needs are the Same vs working Income and With Less Tax Deductions,  & Making More income, which results in my paying More /Not less taxes..

One site I use is Fidelity's  > My Plan Retirement Quick Check calculator in the Retirement/Guidence section.

I also Add another  +10% to my Bottom line I think I will be needing for any given period.

So Far, So Good!