# 2-3 Why Integrate Human Factors?

**HF Benefits.** To help ensure that acquisitions will be **useful, usable and actually used**, it is important to integrate input from human factors specialists and users, starting with the initial stages when a shortfall is being defined and an <span style="color: rgb(0, 0, 0);">Operational Needs Assessment (ONA)</span> is being developed and continuing this HF input throughout the Acquisition Management System (AMS) process.

The [<span style="color: rgb(53, 152, 219);">FAA Human Factors Acquisition Job Aid</span>](https://fast.faa.gov/docs/HFAcqJobAid.doc) indicates that the funding necessary to conduct a comprehensive HF engineering program for a solution has been estimated to be between 0.5% and 6% of developmental costs (depending upon the sensitivity of the solution to HF issues). **The benefit from conducting a comprehensive HF program has been estimated at between 20% to 30% of total acquisition costs.**

Thus, early integration of HF helps focus on performance considerations in a cost effective manner to ensure a useful, usable product that will be actually be used.