23-Ind-B6 Human Factor in Design · May 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Examinations, May 2016 — 98-Ind-B6, Workplace Design (3-hour closed-book exam, Casio/Sharp approved calculators only. The front page states any 5 of the 7 questions, each worth 20 marks, constitute a complete paper; all 7 are answered below.)
Reference texts: Sanders & McCormick, Human Factors in Engineering and Design (7th ed.) — human information processing and compatibility, displays and signal detection, anthropometry and workstation design, physical work and manual materials handling, and workplace/equipment arrangement; Niebel & Freivalds, Methods, Standards, and Work Design — workplace layout, seating, and posture.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
As in Question 3(i): the dominant factors are the physical workload (weight, force, pace), the muscle groups and posture engaged (large dynamic muscle work costs far more than small/static work, and static contraction is disproportionately fatiguing per unit of external work because it restricts blood flow), the environmental conditions (heat/humidity add a thermoregulatory burden on top of the mechanical task demand), the method and skill with which the task is executed (an efficient, practiced method costs less energy for the same output than an awkward one), and individual factors such as fitness, body size, and acclimatization, which set how costly a given task is for a particular worker.
As in Question 3(ii): rest allowances proportional to a task's energy cost are built into the standard time so that total expenditure (work plus recovery) stays within what the body can sustain over a shift; job/task redesign (mechanizing the highest-cost elements, reducing weight/distance, substituting dynamic for static effort) reduces the demand directly; work-rest cycling and job rotation spread high-cost work across the shift or across workers to allow physiological recovery; and pacing the work rate to the individual, rather than a fixed machine pace, lets a worker self-regulate effort against fatigue. Together these prevent a sustained, accumulating energy deficit.
As in Question 3(iii): human strength is the maximum voluntary force or torque a muscle group can exert against an external resistance. Static (isometric) strength is measured at a fixed joint angle against an immovable resistance using a dynamometer or load cell, and must be reported together with the angle at which it was measured, since it varies substantially through the range of motion. Dynamic (isokinetic) strength is measured with a machine that holds angular velocity constant while recording the torque produced continuously through the full range of motion, capturing how strength varies with both joint angle and movement speed — information a single-angle isometric test cannot provide.
