Billions of dollars have been invested in researching and developing high performance Human Machine Interfaces (HMI‘s) – NASA, the US armed forces, Abnormal Situation Management (ASM) and other consortiums and every vendor in the Control Systems market. So, why does the industry still think this effort is not needed or simply a science experiment?
Visit the corporate offices of any major manufacturer, and it becomes obvious that they understand human factors. Office personnel and engineers have the optimal layout to be highly productive, for example when creating a spreadsheet they have good lighting, good chairs, good ergonomics, sound insulation, etc. Then, we visit that same company’s process control rooms and we don’t see those same “human factors” being applied in a control room environment such as light, layout, etc.
Using a simple visual approach, we will examine how an operator can be trapped by the HMI and why the billions in research can be put to use immediately. Some quick examples will help to set it in context. You will see that the HMI is not an island- it needs complete consideration of other human factors to be useful. We will look further at this in a future blog during the series under this same title. But, just to set the scenery, let’s see how an incident happens;
The following diagram is familiar to many, and represents the targeting of plant operations to attain the proper mix of product production, quality, and safety among other constraints.
Note that typical graphics allow an operator to “view” about 25% of the process at any given moment, and significant navigation is required to see the other 75%- but not all in one large view.
To achieve desirable results, the center circle may be moved about, and even operate up against constraints, but the constraints do not change.
Should the protection barriers collapse in a region where the operator cannot pay attention, an incident catches them from the back side. Often, nuisance alarms may be hiding this loss of protection. Or, it could be the loss of an important asset that is not immediately noticed.
Collapsed protection layers due to asset failure lead to an incident
Things go boom. (not always boom, but never good).
The key is that operators do not find an incident- an incident finds them due to poor situational awareness.
You will often see this occurrence referred to in literature as the “Swiss Cheese Model”- where holes align perfectly in the protection layers to lead to an incident.
And this is more often than not blamed on the unit operator because he/she was the last one to touch anything.
In subsequent posts, we will address the things that can be done to assist an operator, and operations support to be able to make the right decisions. It gets down to managing the risk that today’s systems inherently present in highly safety-critical manufacturing operations. It involves having the right alarms, the right HMI, and basically the right information at the right time to make timely decisions. Take advantage of those BILLIONS of dollars that have been invested in Situational Awareness to the potential benefit of your operations. Stay tuned.