23-Ind-A2 Analysis and Design of Work · December 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — December 2015 — 98-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. The source prints Question 3's second and third sub-parts both labelled “(iii)” in the question text (and the marking-scheme line repeats “(ii)” for the same slot) — a typesetting slip; they are answered here in the marking-scheme order (i)/(ii)/(iii), 8/6/6 marks.
Reference texts: Niebel & Freivalds, Niebel’s Methods, Standards, and Work Design (13th ed.) — operations analysis and process/flow charting, motion economy, multiple-machine assignment, stopwatch time study, performance rating and allowances, predetermined time systems (MTM/MOST), work sampling, and wage-incentive and job-evaluation 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.
MTM decomposes any manual task into a small set of fundamental hand/arm motions, each with its own letter symbol and a time-value table indexed by classified characteristics (distance, weight, difficulty of control):
| Symbol | Motion | What it captures |
|---|---|---|
| R | Reach | moving the empty hand to a destination; time depends on distance and the type of object reached for |
| M | Move | moving an object with the hand; time depends on distance, weight, and type of destination control |
| T | Turn | rotating the hand/wrist/forearm about its axis, by degree of rotation and resistance |
| AP | Apply pressure | a brief, deliberate force applied without significant motion |
| G | Grasp | gaining manual control of an object, classified by ease of grasping (e.g., interference from other parts) |
| P | Position | aligning, orienting and engaging one object with another, by fit class and symmetry |
| RL | Release | relinquishing control of an object |
| D | Disengage | separating one object from another, by fit tightness and care required |
A second family covers body, leg and eye motions used when the hands alone cannot complete the task — foot motion (FM), leg motion (LM), side step (SS), bend and arise (B, AB), kneel (KOK, AKOK), sit (SIT), stand (STD), turn body (TBC1/TBC2), walk (W-FT, W-P), eye travel (ET) and eye focus (EF). Every motion in an operation is classified into one of these symbols, looked up in the corresponding TMU table (1 TMU $=0.00001$ hr $=0.0006$ min), and the values are summed to build the normal time for the whole cycle without ever timing or rating a live operator.
“Rating creep” toward looseness happens because performance rating is a repeated subjective judgement: an analyst who rates leniently today has no independent check, and successive analysts (or the same analyst over years of practice) can drift toward ever more generous ratings without anyone noticing until standards across the plant have become systematically loose. Predetermined motion-time data such as MTM break this feedback loop because the time value for each fundamental motion is fixed once, from a large-sample film study, and never re-judged by the analyst applying it on a new job — two different analysts studying the same task with the same table must arrive at the same normal time, because there is no rating step left for personal judgement to enter. Because the values are external, published and shared across companies using the same system, adopting MTM removes the single largest source of standard-to-standard inconsistency; any apparent looseness afterward must be a genuine method change, exactly the trigger the standards-maintenance program of Question 4(ii)/(iii) is designed to catch.
MOST groups the individual reach/move/grasp/position motions of MTM into a handful of standard activity sequences (General Move, Controlled Move, Tool Use), each scored by a short list of index parameters rather than element-by-element lookup, which gives it several practical advantages over element-level MTM: (1) speed of application — a MOST study of a given operation typically takes a fraction of the analyst-hours MTM would require, since whole motion groups are scored at once; (2) lower analyst-training cost — fewer, coarser sequence models are easier to learn and apply consistently than the full MTM motion catalogue; (3) it retains MTM’s objectivity — because the sequence-model index values are themselves derived from the same predetermined motion-time data, it offers the same freedom from subjective performance rating (Question 5(ii)) at a fraction of the study cost; (4) it is well suited to longer-cycle, less repetitive work where MTM’s fine motion-level detail is unnecessary and uneconomical to apply; and (5) its parameter-and-index structure is easily computerized, so standards can be generated, revised and audited from a work-element database rather than a fresh manual study each time.
