Allocation of functions is known by human systems integration professionals as encompassing both a process and a product. As a process, function allocation refers to the sequence of steps involved in establishing the alternate roles, responsibilities, and requirements for humans and machines in a complex human‐machine system. As a product, function allocation refers to the end state of the application of the process, the optimal distribution of roles, responsibilities and tasks between humans and machines.When the system development objective is to downsize emerging systems as compared with existing systems, the focus of the allocation of function effort changes from an emphasis on optimizing human roles to minimizing human involvement in system functions. In addressing the issue of performing system functions with fewer humans as compared with existing systems, the function allocation strategy is not simply to assign functions to automated or manual performance on the basis of differential capabilities and capacities of the two, as exemplified in the Fitts’ List approach. Rather, the strategy is to automate functions to the extent needed to enable the required reduction in workload and manning, with attendant provisions for decision aiding, task simplification, and design in conformity with human engineering standards to ensure adequate levels of human performance and personnel safety.Another change in emphasis when allocating functions for a reduced manning system is the focus on interaction between human and machine. In the reduced manning environment humans and machines are not viewed as competing resources to which responsibilities are assigned on the basis of their unique and individual capabilities but rather as cooperative elements of a system interacting and collaborating in synergy to achieve the system objectives.

Accident investigations and subsequent hazard analysis studies of power mower accidents conducted by the Consumer Product Safety Commission (CPSC), indicated that the current version of the American National Standard for Turf Care Equipment - Power Lawn Mowers, Lawn and Garden Tractors, and Lawn Tractors - Safety Specifications (ANSI/OPEI B71.1-1986) might benefit from review and/or revision. The analyses indicated control activation, placement and/or operation may have contributed to a number of the accidents reviewed. Accordingly, special emphasis was to be focused on review of Part III: Ride-On Mowers, Lawn Tractors, and Lawn and Garden Tractors, paragraph 13., Controls. This paper describes the approach utilized in development of the inputs to update ANSI/OPEI B71.1-1986. Additionally, the paper describes a brief overview of the voluntary standard review/acceptance process.

As military systems become more advanced, more capable, and more sophisticated, they often become more complex. Of primary concern to the human factors specialist is the development of advanced control and display concepts, and application of reasonable tradeoff studies which will guide, if not drive the assessment of these concepts. Similarly, when confronted with conflicting standards and specifications, the human factors engineer must be able to effectively reconcile these discrepancies. Generally the issues pit system constraints (i.e., complexity and development and/or life cycle costs) against operator performance requirements or criteria. The principal objective of this paper is to identify and detail human factors issues requiring consideration when developing command and control concepts for advanced armored military vehicles within the Army's MANPRINT initiative. This paper draws on the authors' experience and expertise in the design and development of armored vehicles to point out the tradeoff considerations and processes necessary in designing complex military systems.

Data from accident rate field tests have suggested that the use of Daytime Running Lights (DRL) on vehicles may have potential for reduction of collision likelihood and severity. With regard to the possible introduction of DRL in the United States, a number of research and design issues have arisen. These involve effects of design parameters on vehicle conspicuity under daylight conditions including central lamp intensity, beam distribution, lamp area, lamp color, number of lamps, and lamp/background contrast. Experiments were conducted to determine effects of DRL design parameters on peripheral detection of an oncoming vehicle under daylight conditions, detection of operating turn signals in the presence of a masking DRL, and degree of discomfort glare produced by DRL under twilight conditions.

Remote Access Data Base (RADB) technology offers a variety of opportunities for rapidly acquiring and disseminating information. However, if the exchange of information is to be optimized, issues concerning the RADB user-computer interface (UCI) must be identified and addressed. For the purposes of this study, the major issues in the operation of RADBs focused primarily on the search and retrieval requirements of the remote user, who is unlikely to be willing to devote much time or effort to learn about the data base system. Many remote users will fall into the category of low sophistication with regard to details of the design and operation of the system. To resolve these issues, it is desirable to include features in the RADB UCI which will enhance the effectiveness and power of the search while minimizing the effort required td master use of the system. Differences in features related to the design and operation of the user-computer interfaces of the various RADB shells were identified from product literature. These differences were translated into questionnaire items designed to allow respondents to indicate the relative importance of each feature. The survey was organized into three areas: user access, search and retrieval protocols, and on-line help. Users ranging in experience from daily access to yearly access, were surveyed. The data were subjected to the appropriate statistical analyses. The preliminary results revealed that query procedures and search and retrieval protocols are of utmost importance to the users surveyed. Guidelines of RADB UCI design were developed from the results of both the surveys and literature reviews.