Human Case Study Essay.
This chapter provides three examples of specific system development that illustrate application of human-system integration (HSI) methods in the context of the incremental commitment model (ICM). The examples are drawn from the committee’s collective experience and specific application of the concepts developed during our work to these particular projects. They represent projects at three stages of development: the early stages of planning, in mid-development, and fully realized.Human Case Study Essay.ORDER HERE A PLAGIARISM-FREE PAPER HERE
The first example involves the development of unmanned aerial systems and identifies numerous HSI issues in these systems that will require solution. This example provides a “notional” application of human factors methods and potential implementation of the incremental commitment model. Human Case Study Essay.The case study illustrates the theme of designing to accommodate changing conditions and requirements in the workplace. Specifically, it addresses the issue of adapting current unmanned aerial systems to accommodate fewer operators, with individual operators controlling multiple vehicles. Human Case Study Essay.The hypothetical solutions to this problem reveal the potential costs of reliance on automation, particularly prior to a full understanding of the domain, task, and operator strengths and limitations. This case study also reveals the tight interconnection between the various facets of human-system integration, such as manpower, personnel, training, and design. In other words, answering the “how many operators to vehicles” question necessarily impacts design, training, and personnel decisions.
The second example focuses on a large-scale government implementation of port security systems for protection against nuclear smuggling. The example discusses the HSI themes and incremental application of methodsHuman Case Study Essay.
during the iterative development of the system. This case is useful for illustrating application of human factors methods on a risk-driven basis, as they tend to be applied as needed over time in response to the iterative aspects of defining requirements and opportunities, developing design solutions, and evaluation of operational experience.Human Case Study Essay.
The third example describes development of an intravenous infusion pump by a medical device manufacturer. This example is the most detailed and “linear” of the three cases, in that it follows a sequential developmental process; the various systems engineering phases are discussed in terms of the human factors methods applied during each phase. Human Case Study Essay.This case study illustrates the successful implementation of well-known HSI methods, including contextual inquiry, prototyping and simulations, cognitive walkthroughs for estimating use-error-induced operational risks, iterative design, and usability evaluations that include testing and expert reviews. The importance of the incremental commitment model in phased decision making and the value of shared representations is also highlighted.Human Case Study Essay.
Each of these examples is presented in a somewhat different format, as appropriate to the type of development. This presentation emphasizes one broad finding from our study, which is that a “one size” system development model does not fit all. The examples illustrate tailored application of HSI methods, the various trade-offs that are made to incorporate them in the larger context of engineering development, and the overall theme of reducing the risk that operational systems will fail to meet user needs.Human Case Study Essay.
Unmanned aerial systems (UASs) or remotely piloted vehicles (RPVs) are airplanes or helicopters operated remotely by humans on the ground or in some cases from a moving air, ground, or water vehicle. Until recently the term “unmanned aerial vehicle” (UAV) was used in the military services in reference to such vehicles as Predators, Global Hawks, Pioneers, Hunters, and Shadows. The term “unmanned aerial system” acknowledges the fact that the focus is on much more than a vehicle. Human Case Study Essay.The vehicle is only part of a large interconnected system that connects other humans and machines on the ground and in the air to carry out tasks ranging from UAS maintenance and operation to data interpretation and sensor operation. The recognition of the system in its full complexity is consistent with the evolution from human-machine design to human-system design, the topic of this report. It highlights an important theme of this book: the need for methods that are scalable to complex systems of systems.Human Case Study Essay.
Unmanned aerial systems are intended to keep humans out of harm’s way. However, humans are still on the ground performing maintenance, control, monitoring, and data collection functions, among others. Reports
In addition, this issue has strong ties to questions of manning. The manning questions are “How many operators does it take to operate each unmanned aerial system? Can one modify the 2:1 human to machine ratio (e.g., two humans operating one UAS) to allow for a single operator and multiple aircraft (e.g., 1:4)?” Automation is often proposed as a solution to this problem, but the problem can be much more complex. Automation is not always a solution and may, in fact, present a new set of challenges, such as loss of operator situation awareness or mode confusion. Furthermore, the manning question is a good example of how HSI design touches other aspects of human-system integration, such as manpower, personnel, and training. That is, the question of how many vehicles per operator is not merely one of automation, but also involves the number and nature of the operators in question.Human Case Study Essay.
This example is based on an ongoing debate about the manning question, which has not been fully resolved. Therefore some aspects of the case are hypothetical, yet not improbable. In this example we assume that the objective of the design is to change the operator to UAS ratio from 2:1 to 1:4. That is, instead of two operators for one UAS there will be one operator for four UASs. This operator to UAS ratio is a requirement of the type that may be promulgated by the Department of Defense with minimal HSI input. It could be too late for human-system integration, which needs to be fully integrated into the engineering life cycle before system requirements have been determined. It could be too late in the sense that up-front analysis might have revealed that an effective 1:4 ratio is beyond the capabilities of current humans and technology under the best of circumstances. If this is the case, then there is a huge risk of designing a system that is doomed to fail. Even worse, this failure may not reveal itself until the right operationaHuman Case Study Essay.l events line up to produce workload that breaks the system.
In our example, we present another scenario. The design of a UAS with a 1:4 ratio of operator to system is carried through the ICM development process to illustrate the potential role of human-system integration and one of the themes of this book. The Department of Defense is one of many
critical stakeholders in this scenario, all of whom are to be considered in the satisficing process that ensues.
In the earliest exploration phases of ICM development, the problem space and concept of operations are defined, and concept discovery and synthesis take place. Table 5-1 provides highlights of the entire example. It is often the case that human-system integration is not brought into the development cycle at this point, although at great risk. Up-front analyses, such as interviews of UAS operators, observations of operations of 2:1 systems, examination of mishap reports, understanding of the literature and data, an analysis of the 2:1 workload, event data analysis targeted at communications in the 2:1 UAS system, application of models of operator workload, and work flow analysis are all methods that could be used to explore the HSI issues in the current UAS system.Human Case Study Essay.
There is much that could come from this kind of up-front analysis. One hypothetical possibility is that the up-front HSI analyses could determine that UAS workload is not constant but peaks in target areas where photos need to be taken or in situations in which the route plan needs to change.
One of the key principles of ICM development is risk management, including risk-driven activity levels and anchor point commitment milestones. What are the risks if human-system integration is not considered early in the development life cycle? In this case, the formal requirements that are established may target workload reduction incorrectly. For example, autopilot automation might be developed to help to get multiple UASs from point A to point B and so on. This might have the effect of reducing workload when a reduction was not needed, while providing no relief from the high-workload tasks. Ultimately the neglect of up-front human-system integration could result in a system that is ineffective or prone to error. Consideration of risks like these should guide system development.Human Case Study Essay.
What if there is not enough time to interview UAS operators and to do a thorough job in the exploration phase? There is also risk associated with application of costly up-front techniques. The up-front methods used often during the exploration phase of the life cycle can be tailored to meet time and budget constraints—another theme of this book. For example, in this case in which the manning question is the issue and automation appears to be a promising solution, it would make sense to focus on aspects of the task that may be automated and the workload associated with each. One caveat is that decisions on how to scope and tailor the methods require some HSI expertise in order to target the aspects of human-system integration that promise the most risk reduction.Human Case Study Essay.
As system development progresses, other principles of ICM development come into play, including incremental growth of system development and stakeholder commitment. This part of the development life-cycle synthesis leads to construction, invention, or design that is iteratively refined as it is evaluated. HSI activities that would be useful at this point include function allocation and the development of shared representations, such as storyboards and prototypes.Human Case Study Essay.
Based on the previous finding of fluctuating workload, it may be decided that human intervention is needed at target areas and during route changes, but that the single operator can handle only one of these peak-workload tasks at a time. It may also be determined that, although automation could handle the routine flight task, an even more important place for automation is in the hand-off between the flight tasks and the human planning/replanning operation. The automation would therefore serve a scheduling and hand-off function, allocating complex tasks to the human operator as they arise and in order of priority (e.g., priority targets first). There could also be automation that serves as a decision aid for the targeting task.Human Case Study Essay.
Because only one nonroutine task can be handled at a time under the 1:4 scenario, it may also be decided that operators should be relieved of the flight functions completely but be on call for hand-offs from automation. For example, four controllers could handle the prioritized hand-offs from the automation, much as air traffic controllers handle multiple planes in a sector. Note that this new design and staffing plan are completely different in terms of operator roles and tasks from the former 2:1 operation. It is human-system integration that guided the allocation of tasks to human and machine; without it there would have been many other possibilities for automation that may not have produced the same end-state.Human Case Study Essay.
As the ICM development continues, the system engineers will go from working prototypes to product development, beta testing, product deployment, product maintenance, and product retirement. But there is continual iteration along the way. The incremental growth in the automation for scheduling, hand-offs, and targeting would occur in parallel with the next iteration’s requirements and subsystem definitions (i.e., concurrent engineering). Incremental growth will be influenced by stakeholder commitment. The HSI methods in the later stages include interviews and observations in conjunction with the newly designed system and usability testing. Some of the same methods used in up-front analysis (e.g., event data analysis, participatory analysis) can be again used and results contrasted with those of the earlier data collection.Human Case Study Essay.
The goal of human-system integration at this stage is to verify that the situation for the user has improved and that no new issues have cropped up in the interim. For instance, it may be determined from testing that the targeting decision aid is not trusted by the human operator (a stakeholder)
TABLE 5-1 Example of Human-System Integration for UASs in the Context of the Risk-Driven Spiral
and as a result is not used (a risk). Through iterations, a new design will be tested or the decision aid will be completely eliminated (i.e., stakeholder satisficing).
In this example, human-system integration plays a major role throughout the design process and is critical in the early stages before requirements are established. It can be integrated throughout the design life cycle with other engineering methods. It is also clear that the HSI activities serve to reduce human factors risks along the way and make evident the human factors issues that are at stake, so that these issues can be considered as they trade off with other design issues.Human Case Study Essay.
This example illustrates several lessons regarding human-system integration and system design:
The importance and complexity of the “system” in human-system integration compared with “machine” or “vehicle.”
Design concerns are often linked to manpower, personnel, and training concerns.Human Case Study Essay.
Hypothetical Outcome |
Risks If No HSI |
HSI Value-Added |
Workload not constant; heavy at target areas and for route change |
Ineffective or error-prone system |
Requirements targeted at known system strengths and weaknesses |
Automation takes over flight and hand-offs complex tasks to operator-based on priority |
Operator who is overwhelmed during high workload and bored during low workload |
Design takes into account known machine and human strengths and weaknesses |
Targeting decision aid not trusted by human operator |
Validation and verification would not consider the human limitations in relation to the new system |
Testing takes into account usability and comparison to prior system |
Up-front analysis and HSI input in early exploration activities is critical.
Methods can be tailored to time and money constraints, but HSI expertise is required to do so.
Risks are incurred if human-system integration is not considered or if it is considered late. In this case the risk would be a system that is not usable and that ultimately leads to catastrophic failure.Human Case Study Essay.