This subclause defines actors interacting with a UAFX system during the system's engineering that are referenced in workflow phase descriptions in all parts of the UAFX specifications.

Controls Engineers are responsible for the design of an automation or control system. Their primary responsibility is the programming/configuration of the application code in a PLC, PAC or DCS (etc.) necessary to execute algorithms defining the operation of a piece of equipment. In support of this function, they are typically responsible for integrating automation devices into the controller engineering tools and parameterising those devices with all information necessary for their correct functional operation.

Within Controls Engineer, there are multiple disciplines, including safety engineer, PLC programmer and process automation engineer, all of whom fulfil essentially the same function but with differing expertise.

The Network Engineer, a peer to the Controls Engineer, is responsible for designing and configuring the network infrastructure and implementing network technologies. At the machine or skid level, the Network Engineer is often the same individual as the Controls Engineer.

The Security Administrator has no direct stake in production operations or technologies. They are responsible for ensuring that there is no unauthorised access to production operations (whether from an outside hacker, inside bad actor or former employee). They are also charged with ensuring that the propagation of viruses, worms, malware, ransomware, etc., is restricted and that reasonable measures are taken to ensure resilience against these threats. They are responsible for the security of proprietary data entering and leaving facilities.

The System Commissioner or commissioning engineer is responsible for the start-up of a system once it has been installed in a manufacturing/processing plant. In some cases, the System Commissioner may have operated as Controls Engineer earlier in the project lifecycle. In machine/skid builders, the commissioning engineer may never have met the Controls Engineer in person as they may work in different locations, or the machine design may be many years old.