Essential Element of Investment Policy Statement

John and Mary are high-net-worth individuals seeking to re-evaluate their investment strategy as they plan for retirement in the next 10 years. They have decided to consult a financial advisor to help them create a comprehensive Investment Policy Statement (IPS). The IPS is intended to reflect their unique goals, risk tolerance, and investment constraints.

As the advisor, it is crucial to gather the appropriate information to construct the IPS. Which element is most critical for the advisor to include in John and Mary's IPS in order to align their investment strategy with their retirement goals?