The previous section described four perspectives of function allocation. The technology-centered perspective focuses on the capabilities of automation and function allocations that use those capabilities. The human-centered perspective focuses on human needs and function allocations that best support humans. The team-oriented perspective focuses on team interaction and function allocations that could support teamwork. The work-oriented perspective focuses on work and its environment and function allocation designs that could support effective work, including the ability to adapt to any changes in work environment.
Table 4. Four perspectives and the issues they identified with function allocation Perspective Issues identified
Technology-centered perspective
Incoherency in function allocations in which the human “picks up” any functions beyond the automation’s capabilities
Mismatches between responsibility and authority due to function allocation only considering the capabilities of automation
Function allocation creating the requirement for the human to monitor for automation boundary conditions
Human-centered perspective
workload that is not decreased or is increased by the function allocation, workload spikes and saturation, clumsy automation, and changes in the nature of the workload
Function allocation preventing human adaptation to context such as conflicts between their required actions and their cognitive control modes Function allocation destabilizing the human’s work environment by reducing predictability
Team-oriented perspective
Mismatches between responsibility and authority where a function allocation delegates authority without delegating responsibility Incoherency in function allocations compared to a clearly defined team structure
Interruptive automation compared to human-to-human communication Workload through induced teamwork
Function allocation destabilizing the human’s work environment through poor adaptation of, or rigidity in, coordination strategies
Work-oriented perspective
Mission performance
Interruptive automation relative to the established workflow Automation boundary conditions as a limit to resilience
Function allocation preventing human adaptation to context by limiting strategy selection
Incoherency in function allocations both in terms of clear role distribution and in terms of inter-dependencies where the action of one may drive the actions of the other
51 The issues identified in each perspective are summarized in Table 4. Each perspective identified a subset of these issues. Thus, examining multiple perspectives provided a comprehensive review of these issues based on the findings throughout the literature. Examining the issues listed in Table 4, issues with human-automation function allocation can be summarized as follows:
1) Workload: Issues with workload include changes in the nature of the workload, workload spikes and saturation, and can result from not only the taskwork but also the additional of the teamwork (including human-automation interaction and monitoring) induced by a function allocation.
2) Incoherency in function allocations: Incoherent function allocations do not establish clear roles and efficient work practices for all team members, and may lead to inter-dependent or conflicting activities between agents.
3) Mismatches between responsibility and authority: Mismatches between the assignment of responsibility and authority leave the human responsible for the outcome of automated functions, and, thus, induce monitoring functions to supervise delegated functions.
4) Interruptive automation: Automated functions may unnecessarily interrupt humans or established procedures, especially compared to human-to-human interaction.
5) Automation boundary conditions: Function allocations can be contextually inappropriate where they place automation outside the boundary conditions in which it can effectively and reliably operate.
6) Function allocation preventing human adaptation to context: Function allocation may have implicit assumptions about human behavior as a fixed pattern, which may not hold as human team members adapt to context by selecting strategies or as part of cognitive control.
52 7) Function allocation destabilizing the humans’ work environment:
Predictability in the work environment allows humans to anticipate upcoming tasks; automation can add unpredicted behaviors to their work environment.
8) Mission Performance: Ultimately, function allocations should improve mission performance.
Function allocation is not the only issue with human-automation interaction. As Dekker and Woods (2002) highlighted, another issue is “how do we make them (human and automation) get along together?” Thus, other issues with human-automation interaction go beyond the issues with function allocation noted here. Specifically, function allocation can address the structure of communication and coordination, but interfaces and displays that enable this communication and coordination are also necessary aspects of effective human-automation interaction.
Thus, there are aspects of human-automation interaction that cannot be addressed only by the discussion of function allocation. However, the focus here on establishing a function allocation that addresses the issues identified by the four perspectives is a necessary condition. Not only does function allocation generally need to be addressed at the earliest stages of design, it also often is the only issue that can be addressed early (i.e., before the interface and machine logic have been established).
However, no one definitive phenomenon determines the success of a function allocation. Likewise, no one metric can address the range of issues with function allocation noted here. The lack of a formal approach to assess function allocation has led to musings that allocation is and perhaps forever will be an art (Parasuraman, et al., 2000;
Sheridan, 1998).
To address this problem, this chapter identified issues with function allocation to extend the degree that it may be formally assessed. In addition, the findings also indicate needs for a systematic approach that applies models and for a comprehensive set of
53 metrics to assess function allocation. The next two chapters, then, introduce a modeling framework comprising static work models and dynamics simulations and a set of metrics, respectively, addressing the issues identified and categorized in this chapter.
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