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.
Given.
| Work element | Observed time (min./pc.) | Rating % |
|---|---|---|
| 1. Load drill press | 0.25 | 110 |
| 2. Drill hole with automatic power feed | 0.15 | 100 |
| 3. Check tolerance (go/no-go gauge) | 0.08 | 115 |
| 4. Unload drill press | 0.20 | 120 |
Allowances: 5% personal + 5% unavoidable delays + 5% fatigue.
Find. The normal time and standard time for the operation, in min./pc.
Approach. Normalize each element’s observed time by its own performance rating, sum the elements to get the cycle normal time, then apply the total allowance to the summed normal time (Niebel convention).
| Quantity | Value |
|---|---|
| Normal time, $NT$ | 0.757 min/pc |
| Total allowance, $A$ | 15% |
| Standard time, $ST$ | 0.87055 min/pc |
A properly set standard time is used well beyond the incentive-pay purpose most candidates think of first: (1) production planning and scheduling — converting an order quantity into a required machine/labour-hour load and a realistic due date; (2) capacity planning and manning — determining how many machines, operators or shifts are needed to meet a forecast volume; (3) cost estimating and pricing — the labour content of a quoted price is built directly from standard times; (4) line balancing — assigning elements to workstations so each station’s summed standard time is close to the line’s target cycle time; (5) wage-incentive and wage-payment plans (Question 7(iii)) — standard hour and piecework pay are both defined against a standard time; (6) performance measurement and control — actual output vs. standard is the routine efficiency metric reported to supervision; and (7) make-or-buy and equipment-investment decisions — comparing the standard-time cost of an in-house method against an outside quote or a proposed new machine (as priced for the multiple-machine assignment of Question 3(i)).
A stopwatch time study is carried out as a defined sequence, not an ad hoc timing exercise: (1) select and standardize the job — the method must already be the one that will be used going forward, since timing an unstandardized method produces a standard for a method that will change; (2) select the operator to be studied — normally an experienced, average-paced worker, briefed in advance on the purpose of the study; (3) break the operation into elements — short, clearly bounded, easily identified segments (as in Question 4(i)’s four drill-press elements), each with a distinct start/stop point; (4) time each element over a number of cycles, recording the observed time for every element on every cycle, and discard any abnormal cycle caused by a documented irregularity; (5) performance-rate the operator on each element as it is timed, judging the observed pace against the analyst’s internalized 100%-normal concept; (6) compute the normal time for each element (mean observed time × rating) and sum to the cycle normal time; (7) apply the appropriate personal, fatigue and delay allowances to obtain the standard time; and (8) document and issue the standard, including the method description it is tied to, so it can be correctly re-applied or re-studied if the method later changes (Question 4(ii)’s standards-maintenance link).
