Over the years, the industry has been focusing on improving the human-machine interface (HMI) associated with developing digital technologies. The primary aim has been to optimise machines by allowing humans to interact with them more efficiently. What has not been in focus during the digital age evolution is the impact of this technology on human factors. The terms human factors and HMI are often used interchangeably, though these terms are far from synonymous. HMI refers to the human interaction with the display and software, which serve as the human interface with the applications present on the computer system.
Over the years, the control room operator’s tasks have become increasingly complex. The number of sources and data inputs has grown considerably. Meanwhile, regulations, industry standards and operating procedures strictly control how the plethora of operator applications are integrated.
At one end of the spectrum we find operator workspaces composed of numerous applications, all running on stand-alone systems. Monitoring and control are conducted via separate operator stations, each with a dedicated screen, mouse and keyboard. The function keys and HMI conventions also vary from application to application. For reporting tasks, operators need to gather information from multiple systems. This is time-consuming, slows down the response time, and requires the operator to remember information from different systems.
Integrated systems, on the other hand, provide many advantages and opportunities. Control rooms have all necessary process control and safety information presented by a single integrated system, which allows information from different sources to be made available to other support applications such as information management systems, shift logs and production monitoring. This enables the sharing of reports, key performance indicators and other data. In such systems, reports can be generated and distributed automatically, thereby relieving the operator of this task. The main drawback of such a solution, however, is the cost, time and effort of implementation.
There is a more practical way to achieve higher operator efficiency through desktop integration, which is more cost- and time-effective than full-system integration. Such an arrangement would not risk invalidating application warranties and maintenance agreements. Sometimes, control rooms too have a lot of separate system hardware components assembled in an ad hoc, haphazard way. The result is a confused layout and cluttered workstations, with no overall structure, requiring operators to move both physically and mentally between systems. When an operator moves from one system to another to complete a task, the chance of human error increases and the movement can cause a delay in noticing an event, thus increasing the operator response time and leaving little chance for an early recovery. KVM (keyboard, video and mouse) switches can reduce the number of keyboard and mouse sets, but they require the operator to manually select the system the KVM is connected to. Also, KVM solutions, which typically have a one-application/one-screen concept, have limited flexibility with regard to optimising visualisation.
System integration also has a significant effect on the HMI. Good HMIs are the key to good situational awareness. On the other hand, disparate HMIs increase operator workload and the risk of error. Further, operators might not always be physically in front of the right application or screen at the right moment. This makes it difficult to gather the right information in a timely manner to diagnose problems. Even worse, this information may be obscured by another application window that is irrelevant to the situation. In certain cases, where control room design follows standards such as ISO 110643, fully integrated HMIs based on a user-centred design process are underpinned by an HMI philosophy and an HMI style guide. However, such an approach may not be easy to apply to upgrades, where legacy equipment and systems are involved, or in industries where many different vendors and different types of applications are involved.
Technology has evolved within the visualisation space so that there is an alternative for the extreme levels of HMI integration as mentioned above. Visual integration delivers many of the benefits of multi-application HMI integration, but avoids the cost. This means that the right information can be provided directly to the operator precisely when needed. A visually integrated system also enables single mouse and keyboard interaction. In addition, visual integration allows operators to optimise the environment to their personal needs or operational requirements in a normal or special event mode. Another benefit of this approach is that it allows operators to save their personalised settings and activate them from any operator workstation at any time. The flexibility of visual integration does not compromise corporate policies and procedures regarding IT infrastructure.