Question 5 of 7: Methods-Time Measurement, MOST, and Fundamental Motion Data as a Defence Against Rating Drift

Question 5: Methods-Time Measurement, MOST, and Fundamental Motion Data as a Defence Against Rating Drift (20 marks)

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.

(i) Fundamental Motions and Symbols Used in MTM

Methods-Time Measurement decomposes any manual task into a small set of fundamental (basic) hand and body motions, each identified by a short code letter and assigned a time value in Time Measurement Units (1 TMU = 0.00001 hr = 0.0006 min) that depends only on the motion's classified parameters, never on who performs it. The principal fundamental motions and their symbols are: Reach (R) — moving the empty hand toward an object, classified by distance and the certainty of the object's location (Case A through E); Move (M) — transporting an object with the hand, classified by distance and by whether the object is moved to an exact location, against resistance, or with care; Turn (T) — rotating the hand/wrist/forearm about the long axis of the arm, classified by the degree of rotation and the resistance encountered; Grasp (G) — closing the fingers/hand around an object, classified by the object's size, shape and accessibility; Position (P) — aligning, orienting and engaging one object with another, classified by the fit's symmetry and ease of handling; Release (RL) — simply opening the fingers to let go of an object; Disengage (D) — separating one object from another, classified by the fit and the care required; and a further group of body, leg and eye motions (e.g. Foot Motion, Leg/Walk, Eye Travel, Eye Focus) used when the task is not purely hand-based. Each symbol carries subscripted parameters (e.g. distance moved in inches, weight class) that key into the published MTM tables to look up the associated TMU value.

(ii) How Fundamental Motion Data Offset the Tendency Toward Loose Standards

"Rating creep" toward looser standards occurs because performance rating is a repeated, subjective judgement with no independent check: an analyst who rates leniently today faces no automatic correction, and successive analysts — or the same analyst over years of practice — can drift toward more generous ratings without anyone noticing until standards plant-wide have quietly loosened, exactly the concern raised by the question and echoed in the standards-maintenance discussion of Question 4(ii).

Predetermined motion-time data (MTM, and its derivative MOST in part (iii)) break this feedback loop because the time value assigned to each fundamental motion is fixed once, from a large, independent film-study sample taken decades ago, and is never re-judged by the analyst applying it to a new job. Two different analysts studying the identical task with the same MTM table must arrive at the same normal time, because there is no rating step left in the procedure for personal judgement to enter — the "rating" is, in effect, built into the published data once, by the original researchers, rather than re-made subjectively on every study. Because the values are external, published, and shared identically across every company using the system, a plant that adopts MTM removes rating drift as a possible explanation for a standard changing over time: any apparent change in a standard set from fundamental motion data must reflect a genuine method change, which is precisely the trigger the standards-maintenance program of Question 4(ii) is designed to catch, rather than a slow erosion of judgement.

(iii) Basic Advantages of MOST

The Maynard Operation Sequence Technique is a second-generation predetermined time system, built on the same fundamental-motion-time principle as MTM but organized around whole activity sequences rather than individual motions, giving it several practical advantages: (1) speed of application — because MOST classifies an entire action (e.g., moving an object freely through the air) into one of a few standard sequence models instead of looking up each Reach/Move/Grasp/Position separately, a MOST study typically takes a small fraction of the analyst time an equivalent MTM study would require; (2) lower training and application skill required — fewer parameter tables and simpler classification rules make MOST easier to learn and apply consistently than full MTM; (3) still analyst-independent — like MTM, MOST removes subjective performance rating from the procedure, retaining the rating-drift protection of part (ii); (4) well matched to longer-cycle, lower-repetition work — the coarser sequence-level granularity that costs some precision on very short, high-repetition cycles is well suited to the batch and job-shop work where MTM's motion-level detail would be uneconomical to apply; and (5) computer-application friendly — the standardized sequence-model structure lends itself readily to software-assisted standard-setting, further reducing analyst time per standard.