Alion Science and Technologies, MA&D Operation and Basic Commerce and Industries (BCI) have developed a new tool entitled Engineering Control Analysis Tool (ECAT). ECAT was developed under a Phase II Small Business Innovative Research (SBIR) project sponsored by the Naval Surface Warfare Center (NSWC) Dahlgren Division (DD). The goal of ECAT is to allow system engineers, human factors professionals, contractors, and others involved in the development and acquisition of engineering control monitoring tools and systems to impact design decisions very early in the requirements generation process. Being able to evaluate design decisions early in the design cycle will allow better decisions to be made prior to implementation, resulting in reduced development, training, and operational costs.
The Navy’s goal is to automate many monitoring and maintenance functions through the use of embedded sensors and automation, and to initiate a Reliability-Centered Maintenance (RCM) program. RCM will shift maintenance from being iteratively performed on a routine schedule to being done “on-demand” when indicators (data from sensors and information developed from analysis of these data) suggest that maintenance is needed.
Under normal operating conditions, many engineering control functions that are currently workload intensive could safely be automated, with a corresponding reduction in shipboard manpower requirements. But, when off-nominal conditions occur in highly automated systems, experience tells us that the monitor/operator may be slow to detect that important parameters are changing and be unable to maintain adequate situation awareness (SA). Monitoring system status, detecting when parameters begin to deviate, and maintaining situation awareness to determine an appropriate course-of-action can impose a significant cognitive workload on a monitor/operator. If the workload is too high, delays and errors resulting in degraded performance will be the result.
But, conversely, if the operator does not stay engaged because task involvement is too low, poor SA and delayed/degraded responses are also likely to result. Ideally, the monitors/operators of a highly automated system remain engaged and maintain appropriate situation awareness, but are not overloaded, so they have the resources to respond when an off-nominal situation arises. The challenge is to design the interface to the automated system with a cognitive workload high enough to keep the monitor/operators in-the-loop (moderate, meaningful workload demands), but not so high that they are unable to detect and respond to off-nominal situations as they arise (they have enough residual perceptual and cognitive resources to cope).
To create a human (monitor/operator) interface to an automated system that keeps the operator in-the-loop, the designer must be able to answer the following questions:
“What does the operator need to know about current equipment status and what has been happening over time?”
“What data and information will provide him or her with the status of equipment and the relevant history?
“How will the operator use these data/this information to diagnose and correct off nominal machinery events and conditions (what decisions will he or she make)?” and,
“What is the most effective way to present these data/this information?”
The objective of this effort was to develop and demonstrate a tool that can enhance the ability of human systems integration professionals and systems engineers to identify shipboard engineering operational tasks in which a high potential for human overload and error can be expected, and to develop solutions in the form of prototype displays that will provide needed information and situational awareness while reducing cognitive workload.
Designing a graphical user interface (GUI) or panel layout is an essential part of any design process. The GUI consists of components (e.g. screens, menus, buttons, forms, etc.) and how they behave. To allow users to manipulate and analyze multiple designs, ECAT includes a Display Designer capability. The Display Designer included in ECAT allows the user to define the screens and panels that are used by engineering control personnel and the sequence they are used in. When the model is executing, the design and sequence provide timing, workload, and human error potential values.
The Display Designer assists in the automated design and evaluation of GUIs under standard windowing environments. Tools and techniques already exist to evaluate interface designs before a product is built. Checklists and heuristics are often used early in design, but do not provide objective measures of design differences. GOMS (Goals, Operators, Methods and Selection Rules) (Card et. al, 1983) based techniques provide a quantitative method for evaluating alternative system designs, but are labor intensive to create and require consistent application for valid comparisons. We have included a unique capability within ECAT by abstracting the Keystroke Level Model GOMS technique to a higher level -- the user interface component level.
The screen designer allows the user to define applicable screens along with applicable widgets and layout. Users simply drag components from the tool palette onto the screen. For each component, they specify layout and functional attributes to indicate parameters that will be used for the evaluation.
For more information on ECAT, please contact us at MAAD_info@alionscience.com.