Despite some delays, Microsoft is set to deliver a military version of the Microsoft HoloLens, the Integrated Visual Augmentation System (IVAS) headset, to the US Army this year.

The military has already invested $480 million on 100,000 prototype augmented reality headsets and the project is set to roll out at scale later this year, in a contract which could cost as much as $22 billion.

In a new report, the US Dept of Defense’s Office of the Inspector General (OIG) has questioned if this is money well spent.

“Procuring IVAS without attaining user acceptance could result in wasting up to $21.88 billion in taxpayer funds to field a system that soldiers may not want to use or use as intended,” the Pentagon oversight body wrote in an audit report this month.

The report notes that “if soldiers do not love IVAS and do not find it greatly enhances accomplishing the mission, then soldiers will not use it,” the report disclosed.

The report does note that feedback from surveys showed “both positive and negative user acceptance,” while Microsoft said “Our focus continues to be on developing IVAS to be a transformational platform that will deliver enhanced soldier safety and effectiveness.”

Douglas Bush, assistant secretary of the Army for acquisition, logistics and technology, noted that the $22 billion cost estimate was the maximum amount, if the Pentagon ended up rolling out the headsets very widely to all branches of the military.

“This is a contract ceiling that includes all possible hardware, components, and services over a ten-year period at the worst possible pricing structure. Less than half of this total is possible for the US Army. This total includes all possible sales to all sister services, foreign military sales, and all maximized service contracts,” he wrote.

He also noted that initial feedback does not always tell the whole story, as soldiers may need to learn how to best make use if the new technology, saying soldiers did not like night-vision goggles when they were introduced in the 1970s, but now, they are widely adopted by the Army.

The army auditors however insist a measurable goal is necessary.

“While we agree there is inherent tension between user acceptance and opportunity, having an established measurement or goal enables officials to know that close combat forces accept, want to use, and can function effectively with IVAS,” they concluded.