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Many descriptions of product development are based on a timeline of activity. Timelines typically do not characterize the underlying strategy and flexibility embodied in the technical activity that actually takes place between activity nodes. Timelines alone will inhibit evolving to a more rational approach to product development. The view of engineering described in this paper is a functional view of engineering. It is what engineers do. It is aligned with the technical tools used by engineers. It applies to both product development and manufacturing. It's purpose is to enhance understanding of the function of engineering activities, including reliability.

The analysis presented in this paper indicates that while 1700 lbf (7560 N) is a realistic femur fracture load for 30-50 ms duration impacts, the human femur can withstand higher loads for shorter-duration impacts. Experimental femur fracture data from cadaver and bone specimen tests are reviewed. These data are used to develop femur load fracture tolerance as a function of impact duration. On the basis of a measured 10% amplification of 1-2 ms input forces by the dummy, the cadaver fracture tolerance is proportionately adjusted to arrive at equivalent load levels for forces measured on current dummy test devices. Experimental dummy test device data are included and compared to the theoretical response of a mathematical model of the human upper leg. This comparison demonstrates that even neglecting the 10% amplification, there are still significant differences in the response of dummy and human upper leg structures for impact durations less than 3 ms.

A new procedure is described for measuring realistic on-the-road vehicle directional response characteristics. Conventional control system analysis techniques are used in the procedure to derive the transfer function relating steer input to vehicle lateral motion. The influence of the driver's limited torque capabilities on the steering system input is introduced in a nontraditional, though direct, manner. This approach produces somewhat different descriptions of vehicle response than have been obtained in the past, when such descriptions did not include this driver influence. Since the resulting transfer function is a unique on-the-road description of the vehicle dynamics, realistic vehicle motion response to any quantifiable steer input can be computed. This procedure offers the additional benefits of test procedure simplicity and minimum test road facility requirements.