If you’re a utility operator, then you’ve probably been working with the same HMI screens for over a decade. However, you now have the opportunity to update the entire SCADA system, including all the screens based on the ISA 101 and high performance HMI standards. Are you scared of change and being phased out? Relax, this change is all about making you the new superhero in your organization—The High Performance Operator. Get your cape ready, because I’m about to tell you how to maximize this new superpower.
Whether maintaining a water treatment, distribution, water collection, or wastewater system or plant, operators are a critical part of providing an adequate and safe supply of water. Today’s operator is faced with ever increasing process complexity, and producers want to make more with either the same or less amount of staff through automation. In small plants, a single operator might be responsible for maintaining all the equipment, including interaction with chemicals, equipment inspection, operating equipment, and environmental reporting. It’s a stressful job, and mistakes can cause emergency situations, including leaks, spills, equipment malfunction, and dangerous safety and health conditions. Mistakes are made for several reasons.
A knowledge-based mistake occurs when an operator does not accurately interpret a situation, either through poor training, biases, insufficient info, or info overload. A rule-based mistake is when the wrong rule is followed, often with confidence. Finally, a slip or lapse can occur when the task is very familiar and requires little thought, or an operator confuses similar tasks and makes the wrong response.
As the system interface, HMI screens are critical to operator performance. So, how does a High Performing HMI lead to you earning a super hero cape? Through simplified screens with situational awareness and intelligent alarming, information overload is reduced, and only the right information is provided at the right time and in the right context, reducing mistakes, errors, and slips, keeping the plant operating safely, securely and high performing, and making it easy to train new operators.
Breaking down the standard
The standard includes simplifying the interface, introducing equipment model navigation, building from a library of standard objects, alarm rationalization, and using KPIs. The goal for these standards is being able to quickly identify and react to a problem. By simplifying the interface, operators can spend less time navigating and improve problem and alarm resolution by:
- Eliminating noise using basic shapes and a basic color palette with minimal colors and many shades of grey
- Minimizing use of colors, and then only to highlight defects in critical process areas
- Repeating the use of basic shapes for common objects like pumps, wells, and motors, and simplify pipe drawings to highlight primary flows, diminishing secondary flows
- Implementing an equipment model so that trending, KPIs and alarms are shown in context with the appropriate assets and equipment
HMI vendors and system integrators should provide customers with a library of high performance dynamos and smart objects that can be quickly repurposed across multiple screens, providing a standard way to visualize common objects like pumps, motors, filters and piping. In summary, less time spent navigating, easy problem recognition and fast path to resolution. Let’s take a look at how this can be done.
Start with a dashboard
Conducting on-site human factor and ergonomic studies with hundreds of water customers in North America, we found that many long-standing HMI systems start with an overview screen covered in titled buttons or laid out as geographical icons on a map. This approach was easy and simple to implement when data was minimal, but as complexity grows, we need to evolve the system to minimize the risk of productivity loss and missed alarms. We see operators cycling through multiple screens to understand the status of process areas and analyze process conditions. While this navigation may become intuitive over time, it can lead to slips or lapses due to lack of concentration.
We solve this problem by creating a high performance HMI dashboard that turns raw data into useful information that is easily understood at a quick glance, accelerating operator insight. A well-designed dashboard includes a combination of live and historical data with situational awareness, and through the use of a limited set of intuitive and recognizable colors, the operator can easily recognize alarms and actionable conditions. This dashboard supports both the seasoned operator and new trainee, and provides a great showcase for supervisors, managers, and customers.
Color alone is not as useful and should not be used as the only method of differentiation, but there is no need to complicate an HMI display with an intricate and detailed design of every part of your plant. The standard describes the benefits of both a greyscale background and the use of simple objects to direct attention and add meaning to the display. In our designs, we utilize both elements to assist with how an operator interacts with alarm conditions and combine alarm limit information with trending so, at a glance, an operator can see whether action needs to be taken or not.
Alarms and Trending
Boosting operator productivity
Alarms are often represented in an alarm summary which dictates the necessary actions of an operator. “Acting on alarms” is a phrase that we hear among operators, yet this can be distracting and can lead to a mistake. Alarming is always stored and viewed through the alarm summary, but the alarm thresholds are an important piece to operating in an optimal condition. From time to time, operators may find themselves disrupted by unexpected alarms, where the culprit is often a large list of data values that take up valuable HMI real estate without providing any context or situational awareness. Our approach is to display these lists in gauge form to show where the value is in relation to the optimal range along with the alarm thresholds, increasing operator productivity.
Trending is used to analyze different circumstances such as a heavy rainfall, a failed piece of equipment, comparing different control outputs and finding similarities. Under ergonomic observation, we find that each operator searches for the data they need in different ways, which can mean reaching outside of their SCADA systems, a practice that is both time consuming and out of context with the real-time info provide by the HMI. Commonly, operators are looking to go deeper on KPIs such as chlorine, pressure, and storage levels. We have found through practice that the best high performance HMI screens provide a four-hour trend adjacent to a gauge that displays current value with both alarm and operating limits, enabling the operator to have a greater understanding of the conditions of the process eliminating the need to dig deeper unless specific interaction is required. The alignment of the objects is also key, as the eyes of most people in the Western world tracks in a “Z” type shape, left to right then down the page.
Information when operators need it most
Like the movement rings found on your smart watch that tell you where you’re at in your overall day, process rings provide a simple status that either encourages further investigation or leaves you satisfied that everything is okay. You can incorporate these rings into your HMI by combining two or more related process values to simplify the operator’s experience. We use these rings to display status of water filters in many water treatment plants. For example, a set of rings could represent flow, pressure and turbidity, and when presented in a layout with other filters, operators can easily recognize different conditions at a glance, and they no longer need to cycle through screens to browse for data—putting the information they need right in front of them.
Steering attention to what matters
With smart phone apps setting a fast pace of technological change, both experienced and new operators expect to navigate their HMI in a similar manner. A common example found on most mobile websites is the so called “hamburger button,” consisting of three horizontal lines that resemble a hamburger in a bun. We utilize this approach to implement a tiered high performance HMI navigation schema that takes up very little space and offers a common and easy way to browse your process areas with less mouse clicking. Higher tiers are the dashboards where larger areas can be displayed in logical formats; for example, a water utility that covers hundreds or thousands of square miles with multiple sites scattered around a region. The well-designed dashboard uses as few as three KPI values to provide a quick snapshot of the site’s health from a high level while showing alarms that steer the operator’s attention to sites that are in alarm.
Working with customers in reviewing their long-standing HMI screens is a fascinating journey into the history of the HMI/SCADA business. Many customers budget an HMI upgrade once in a blue moon, leading to stale and unproductive information that a seasoned operator has become too accustomed to, making it difficult to train a new operator and increasing the risk of mistakes by both. Perhaps it’s your turn for an upgrade, and you are feeling apprehensive about an approach that limits colors, removes complexity from the screens, and changes the way you interact with your process. We suggest you relax, embrace the change, accept the challenge, and be ready to don your cape because the primary outcome of this high performance HMI experience is to make you the new superhero in your organization!