Hollifield adds that PAS recently worked with the Electric Power Research Institute
to proof-test these high-performance HMI concepts at a large coal-fired power plant using several operators and a full simulator. "The tested HMI included proper hierarchy and embedded knowledge, and we found that operator results were better when handling significant abnormal situations," adds Hollifield. "Besides showing useful information instead of just raw data, displays should be designed in this hierarchy that provides progressive exposure of detail. Displays designed from a stack of schematic designs will not have this. They'll be 'flat' like a computer hard disk with one folder for all the files. This doesn't provide optimum situation awareness and control. A four-level hierarchy, including operation overview, unit control, unit detail and support and diagnostics displays, is desired. For example, Figure 2
is an operation overview from a large power plant. We often hear, 'But it doesn't look like a power plant!' Correct! Does your automobile instrument panel look like a diagram of your engine? The display is designed so important abnormal conditions and alarms stand out clearly." [A whitepaper by PAS on these high-performance HMI principles and the EPRI project is located at http://tinyurl.com/a8tdjln
Holistic Human Factors
Besides improving HMIs and displays, enhancing performance also means assisting the physical eyeballs viewing those screens—especially when their owners' attention falters and they get tired. Limiting work hours and potentially dangerous fatigue has long been mandated for airline pilots, first responders, truck drivers and other professions, but it's not as well-known or established in many process operations—where many managers and operators rely on too many overtime hours and consecutive workdays.
See Also: User interfaces should empower operators
To remedy these dangerous situations, the U.S. Dept. of Transportation's Pipeline and Hazardous Materials Safety Administration's latest rules took effect in September 2012, and they require pipeline operators to use display graphics that employ human-factor designs; reduce operator fatigue by limiting consecutive hours and days worked to a more normal weekly schedule; establish thorough alarm procedures; document and learn from incidents; and pay fines up to $1 million or more per violation, according to Ian Nimmo, president of User Centered Design Services Inc..
"More process facilities are investing in control room management (CRM) and human-factor principles, and they're taking countermeasures against fatigue, such as deploying 24/7-style chairs, brighter lighting and better temperature control, providing exercise equipment and enforcing regular breaks," explains Nimmo. "They're also monitoring hours worked by operators and calculating the relative risks of incidents, which is going to force some to hire more staff. Besides providing more human-factors graphics, process managers also need to conduct a risk assessment to make sure their operators can handle the number of alarms they're going to get. Then, they need to take a holistic CRM approach, evaluate the roles and responsibilities of their operators and define exactly what they're supposed to do in specific situations, including normal and abnormal operations and in emergencies."
Curing Computer Clutter
While software and computers of all types are indispensable to manufacturing in general and process control and automation in particular, the downside is an increasingly impenetrable jungle of software applications and packages that don't share data fast enough or allow operators to access information they need to make crucial decisions. Fortunately, some solutions are coordinating different types of software and bringing them into more manageable formats.
For instance, Waterford Township's Dept. of Public Works (DPW,) uses many types of process control, maintenance, documentation, asset management and enterprise software to operate its water collection, distribution and wastewater systems, which cover 36 square miles in Michigan and serve about 75,000 residents. The water system pumps and treats about 8 million gallons per day of groundwater from 20 wells at 12 plants and 100 remote sites, and the wastewater system maintains 300 miles of sanitary sewers and sends the township's wastewater 30 miles away to Detroit for treatment.
See Also: Upgrading a Wastewater SCADA System
Bill Fritz, PE, Waterford's public works director, reports that the water/wastewater systems operate hundreds of pumps, valves, actuators, water quality and other equipment, which are monitored by more than 1200 I/O points and networked via Modbus TCP/IP, a high-speed Ethernet backbone with twin servers, and remote radios and 100 live-video security cameras at its pumping stations. All of this data comes into an unmanned cubicle, where it's been managed by GE Intelligent Platform's (GEIP) Proficy iFix software, and then reports, e-mails and alerts are pushed out to DPW personnel on their laptops, tablet PCs and smart phones.
Also, about two years ago, Waterford DPW added Proficy Workflow software, which automates more processes, serves as an electronic user manual, and performs exception-based reporting, which notifies users of problems so they don't have to go find them. For example, the department built algorithms and templates to indicate if pairs of pumps are alternating correctly at 62 of its pumping stations. This allows Proficy Workflow to provide alerts when the pumps aren't synched properly, so individual visual checks by the operators aren't required anymore.