Here are its key points -
The goal is to pensionize a person's retirement portfolio by examining assets and expenses. The "funded ratio" compares the person's projected assets with the projected expenses, and can help a financial advisor determine an allocation strategy.
In other words, it aims to base a person's asset allocation on the person's capacity to experience investment volatility and to adapt the portfolio based on how much the person can afford to lose.
For example, if you only have 5% surplus beyond funded level, then you can't afford to take on as much risk as someone with a much greater surplus.
According to Russell marketing materials, this adaptive investing approach is implemented through Russell Model Strategies, a series of globally diversified portfolios with a range of asset allocations. Each person's situation determines the appropriate model -- conservative, moderate or balanced.