Having offices work together is difficult in the private sector, but in parts of the federal government it comes with a $56 million price tag.

The U.S. Department of Energy has lost more than $56 million due to poor coordination during implementation of a new telephone system, according to the DoE inspector general.

The telephone system — known as Voice over Internet Protocol, or VoIP — enables "the transmission of voice communications primarily over the Internet."

But transitioning to the new Internet-based communications system across more than 14 department offices, as well as getting parts of it such as "hardware, support services and licensing costs" coordinated, hasn't gone smoothly, the inspector general said.

"We acknowledge that upgrading to a VoIP solution is likely to improve the department's telecommunications infrastructure. However, the path the department is on is not fiscally sustainable or efficient," the IG said.

At Oak Ridge Reservation in Tennessee, for example, all four sites with the VoIP system implemented it differently, meaning they all work differently. That's not what department officials had in mind when they adopted the new system.

VoIP also increases security risks that DoE must contend with in its data networks, an issue the agency is not actively addressing, according to the inspector general.

Only two of the nine sites reviewed had put the installed VoIP systems through cybersecurity tests.

Without improvements in VoIP implementation, "additional, unnecessary expenditures of resources at programs and/or sites," could continue, the IG found.