23-Ind-A2 Analysis and Design of Work · December 2018
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — December 2018 — 17-Ind-A2 Analysis and Design of Work. Three-hour, closed-book exam (approved Casio/Sharp calculator only); any five of the seven questions constitute a complete paper and only the first five answered in the answer book are marked — all seven are solved below for completeness.
Reference texts: Niebel & Freivalds, Niebel’s Methods, Standards, and Work Design (13th ed.) — operations analysis and process charting, principles of motion economy, multiple-machine assignment, stopwatch time study, performance rating and allowances, predetermined time systems (MTM/MOST), work sampling, and job evaluation / wage-incentive systems.
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.
Applied to tool and equipment design, motion economy asks whether a tool can be eliminated or combined with another so a change-of-tool motion disappears, whether its use can be transferred from the hands to a foot pedal, jig, fixture or powered mechanism, and whether its shape, weight and balance let the hand grasp and use it with the least exertion and the shortest path. In practice this yields combination tools in place of single-purpose tools used in sequence; spring- or gravity-return tool holders that pre-position the tool for the next grasp; counterbalanced suspension of heavy powered tools so the operator supplies only guidance force; handle contours that spread grip pressure instead of concentrating it on a narrow edge; quick-acting cam clamps in place of screw clamps where cycle time matters; and control layouts placed for the shortest reach from the operator’s normal working position.
Working conditions are one of the standard operations-analysis approaches (Question 1(iii)), and because the methods analyst is the person who studies and redesigns the workstation in detail, that analyst is best positioned to notice and correct poor lighting, temperature, noise, ventilation or housekeeping at the point the work is actually performed — leaving conditions to a disconnected facilities function routinely produces a technically sound method executed at a station that undermines it. There is also a direct obligation under Canadian occupational health-and-safety legislation (provincial OH&S Acts, WHMIS, CCOHS guidance), exercised in practice through the engineers and supervisors who design the workstation, to provide conditions that do not expose the worker to unreasonable risk.
Working conditions do appreciably affect output: fatigue accumulates faster under poor heat, noise or lighting, directly lengthening the standard time via the fatigue allowance (Question 3(ii)/(iii)); error and accident rates rise with poor illumination and awkward postures forced by cramped layouts; and absenteeism and turnover rise when conditions are unpleasant. The Hawthorne studies, often cited here, showed output rising when lighting was changed in either direction — revealing that attention and social factors also drive output independent of the physical stimulus, not that physical conditions are irrelevant, so both objective improvement of conditions and visible management attention belong in the response.
A human-machine (multiple-activity) chart is a time-scaled chart recording, on parallel vertical bars against a common time axis, exactly what an operator and each machine under that operator’s charge are doing at every instant of a work cycle, divided into working and idle/waiting blocks.
The summary form condenses the chart into one row per resource — here, Operator: 4 min busy / 4 min idle (50% utilized); Machine 1 and Machine 2: 8 min busy / 0 min idle (100% utilized) each, over the steady-state 8-minute cycle (Machine 2’s 6-min run wraps into the first 2 min of the next cycle, so its “Wait” block appears only on the start-up cycle drawn) — with cycle time, working time, idle time and percentage utilization tabulated beneath the chart.
Its main uses are: (1) determining how many machines can be economically assigned to one operator (the multiple-machine assignment problem quantified in Question 3(i)); (2) identifying and quantifying idle time in either the operator or the machine(s) so it can be filled or eliminated by re-sequencing; (3) balancing workload between an operator and automatic equipment, or between operators sharing a line; (4) justifying capital decisions — whether an additional or faster machine, or additional labour, gives the better return; and (5) supporting incentive and cost-standard setting, since the chart makes the true cycle time, not just the busy time, visible.
