A primary reason for developing a strategic asset allocation is to:

Asset classes add value to a portfolio when they have unique risk/return profiles, and they have relatively low or negative correlations to one another. One of the benefits of asset allocation and diversification is to minimize unsystematic risk. Rebalancing policies are often established in the IPS, but establishing the strategic asset allocation will not necessarily prevent overweighting or underweighting due to market changes or tactical asset allocations.