Safety does not come out of a box
The solution to making your process plant a safer place isn’t something you can buy. Much of it depends on changing the ways your people work and think.
Working with safety instrumented systems (SISs) for more than 20 years has taught me that technology alone cannot make process plants safer places to work. Over those years, I’ve been involved with the design and implementation of mission critical technology to satisfy functional safety standards such as IEC61508, IEC61511/ISA84, as well as other application specific standards. As important and helpful as those standards are, personal experience and the frightful number of safety incidents across our industries suggests that we need to go back to basics.
What is a process hazard?
We all have heard the saying, “If you don’t know where you’re going, any road will take you there.” When it comes to risk reduction, we need to have frank and open discussions about the risks we’re facing so we can be clear on where we’re going. The objective might not be to eliminate risk entirely, but to reduce it to an acceptable level that will allow the plant to function while protecting people in the plant along with the community, environment, and equipment.
Therefore, the first step is to understand the hazards and the risk. Without establishing the scope of the hazards, it is not practical to determine the necessary risk reduction required. This should be done to create the safety requirements specification (SRS) necessary to start a system design.
It shouldn’t be a surprise that an effective risk reduction strategy is typically aligned with a corporate safety vision or strategy. The reality of a commitment by senior management to an explicit safety vision becomes woven into the ethos of the company. Every level of the organization must understand the overarching reasons for the vision, and the organizational structure, management processes, technologies, and human resources that create a supportive framework to live the vision. Of course, it is crucial that the vision and values be communicated to people at every level, and that the effectiveness of the communication is verified.
While that may seem like the most obvious point, think of the number of times that safety culture, or a lack of it, is found among the top causes of incidents and accidents in process industries. Consequences of those lapses can range from minor injuries to environmental catastrophes making news headlines worldwide. If that anecdotal evidence isn’t enough, safety culture is top of list when the UK Health and Safety Executive publishes its “Ten Human Factor Issues” affecting safety in process plants.
Functional safety management
The late Trevor Kletz had a way of summarizing safety concepts very clearly. He observed, “We can’t enable people to carry out tasks beyond their physical or mental abilities.… [but] we can reduce the opportunities for such slips and lapses of attention by changing designs or methods of working.”
It is possible to improve safety by introducing and following well-thought-out procedures. Today’s safety standards introduced a functional safety management (FSM) system which created a series of work processes established on top of the traditional quality management system. These work processes address functional safety requirements from design to implementation of a process or system, to its eventual modification or decommissioning. Among other things, the FSM system requires documenting the risk reduction requirements and corresponding validation testing to demonstrate that the intended risk reduction was ultimately achieved. These procedures might require the involvement of two people and the issue of a permit. Such an approach provides an opportunity to run a check by an independent party to verify that everything necessary has been done.
Checklists can be viewed as a job aid that aims to provide a series of prompts that reduce the likelihood that standard operating procedures are not followed, or steps omitted. They are useful at catching slip-type errors where operators or engineers had the intention to perform the activity but were distracted by another task or simply forgot they had not performed the task.
Even when technology alone cannot make process plants safer, it can be made part of the solution. For years, the industry had relied on automation to support engineers, operators, and maintenance personnel in the plant. Today, rather than treating human beings as automatons, the industry can take advantage of new technologies in key areas to enhance the user situational awareness and decision making.
Ergonomics and operator alertness
One aspect of the design process is creating a comfortable operating environment. On any given day, operators need to sustain a high level of alertness and a clear understanding of exactly where the process is as it moves through the production cycle. This requires having real-time access to critical information to support decision making.
Some days are relatively quiet and that decision making process is simple and quite routine. However, it’s well known that humans are much less reliable at performing routine repetitive tasks than machines, and that human error is a frequent cause of malfunction in complex systems. Simply dismissing an accident by attributing the cause to human failing is shortsighted because it does not lead to constructive action. Systems need to be designed around people rather than the other way around. Technologies such as ergonomics, display design, HMI (human-machine interface) graphics, and alarm handling can help to reduce the occurrence or effects of some of these factors. When these can be combined with training simulators and advanced maintenance technologies, improvement in plant safety will soon be noticeable along with significant overall performance improvements.
The role of operators in high-risk industries is clearly an important aspect of overall system design. There is a general consensus that operators’ tasks within control rooms have been largely automated, leaving operators spending the majority of their time as system supervisors and not system controllers. As a result, operator attention, reaction, and effectiveness are often overlooked as areas that can improve the performance and safety of a control system or plant. If the situation deteriorates, all too often an operator is left to understand inconsistent interfaces from a multitude of sources or data where there is not enough information to understand the abnormal conditions enough to take appropriate corrective action.
Fortunately, research from entities such as Center for Operator Performance and the ASM Consortium has led to guidelines for designing control rooms and operator displays to suit the needs of the operators, to promote effectiveness, improve comfort, and present simplified information displays that are easy to understand. All this takes place in a well-designed physical environment in which the operator can simulate the passage of time each day or call attention to a specific type of event. For example, lighting at 3:00 a.m. may be more subdued than at 1:00 p.m., and lights may take on a different color during an emergency. When these kinds of changes can take place, operators are more alert and able to handle the stress of an abnormal condition in the plant.