23-Ind-A2 Analysis and Design of Work · May 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — May 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’s marking-scheme line for Question 3 mislabels its final sub-part “(ii)” a second time instead of “(iii)”; it is answered here in the natural (i)/(ii)/(iii) order that matches the question text itself, 5/5/10 marks.
Reference texts: Niebel & Freivalds, Niebel’s Methods, Standards, and Work Design (13th ed.) — operations analysis, workplace/tool design and motion economy, stopwatch time study, performance rating and allowances, predetermined time systems (MTM/MOST), work sampling, 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.
Each observed element time is first rated to remove the individual stopwatch operator’s own pace, giving a normal time per element; the element normal times are then summed to a cycle normal time, and the company’s allowances are applied once, as a single percentage, to that summed normal time (Niebel’s convention $ST=NT(1+A)$), not element-by-element.
Given.
| Element | Observed time (min./pc.) | Rating |
|---|---|---|
| 1. Load drill press | 0.20 | 115% |
| 2. Drill hole (automatic power feed) | 0.25 | 100% |
| 3. Check tolerance (go/no-go gauge) | 0.10 | 110% |
| 4. Unload drill press | 0.15 | 120% |
Allowances: 5% personal $+$ 5% unavoidable delay $+$ 5% fatigue.
Find. The normal time (NT) and standard time (ST) for the operation, in min./pc.
Approach. Rate and sum each element to get the cycle normal time, then apply the total allowance once to the summed normal time.
| Quantity | Value |
|---|---|
| Normal time, NT | 0.770 min/pc |
| Total allowance, A | 15% |
| Standard time, ST | 0.8855 min/pc (≈ 0.886 min/pc) |
Under a wage incentive program the time standard is not just a planning number, it is the direct basis of every operator’s pay: if the standard is allowed to drift loose (through undetected method changes, tooling improvements, or an unaudited initial rating) operators are effectively overpaid for a job that has become easier, which inflates labor cost, invites “rate creep” grievances when management eventually tries to correct it, and undermines trust in every other standard in the plant once one is discovered to be loose. Conversely a standard that has become too tight (through a hidden material or equipment problem) demoralizes operators, encourages corner-cutting on quality or safety to make rate, and drives turnover and disputes. Accurate maintenance is therefore essential to cost control, production planning reliability, and labor relations simultaneously.
A sound maintenance program should include: (1) a formal method-change control procedure that automatically triggers a re-study whenever tooling, material, layout or process is changed, rather than relying on someone remembering to flag it; (2) periodic audit re-studies of a sample of standards, prioritized by cost impact and complaint history; (3) statistical monitoring of actual earned-hours-versus-standard-hours by job, so a standard drifting loose or tight shows up as a trend before it becomes a dispute; (4) trained, certified time-study analysts whose ratings are periodically checked against reference films; and (5) a transparent grievance/appeal procedure so an operator who believes a standard is wrong has a legitimate channel, which both catches genuine errors and preserves the credibility of the incentive system.
A new operator’s time per piece falls steadily with cumulative production as the person becomes familiar with the method, tooling and workplace — the classic learning curve, typically modelled as $T(n)=T_1n^{b}$ with $b=\ln(\text{learning rate})/\ln 2$ (e.g. on a 90% curve the time per unit falls to 90% of its previous value every time cumulative output doubles). Early in this curve the operator is still learning; a time standard set from those early cycles would be unrealistically loose once the operator is fully trained. Late in the curve the rate of improvement has essentially stopped and the time per piece has flattened to the operator’s true sustainable pace.
The most desirable stage to establish the time standard is therefore after the curve has flattened onto its plateau — once cycle-to-cycle improvement has become negligible and the operator has reached a consistent, trained, sustainable pace. Setting the standard any earlier bakes an unrepeatable “still learning” time into the standard (too loose once the operator is trained); setting it very much later wastes fully-trained production time on unrated work and delays the incentive program (Question 7(ii)) from taking effect.
