HLA 4 Approved by IEEE

The Simulation Interoperability Standards Organization (SISO) is pleased to announce that an update to the High Level Architecture standard, referred to as HLA 4, was approved by IEEE during the recent 2025 Simulation Innovation Workshop (SIW).  The preliminary publication date is set for late March or early April.

HLA 4 is the result of many years of hard work by the members of the HLA Product Development Group (PDG), and offers improved security, scalability, extensibility, cloud and container readiness, and full life-cycle support.

SISO congratulates the HLA 4 team for their tireless hard work and dedication.

Please look for the official publication announcement in the next month or two. In the meantime, please note that SISO members may download one copy each of all three, active SISO-sponsored IEEE Standards families for free:

• IEEE Std 1278™ — Distributed Interactive Simulation (DIS)
• IEEE Std 1516™ — High Level Architecture for M&S (HLA)
• IEEE Std 1730™ — Distributed Simulation Engineering and Execution Process (DSEEP)

This benefit is for full, paid SISO members only.  Free guest members do not qualify, so this would be a good time to upgrade your membership, if you want to obtain a free copy of HLA 4. 

Please see https://www.sisostandards.org/page/Membership for more information, and contact Patrick Rowe at prowe@sisostandards.org with any questions.