Rest Allowances - Fundamentals and Assessment Tools for Occupational Ergonomics - page 754

TABLE 38.6 Concentration / Anxiety Allowances

Points Degree

0 Routine simple assembly; shoveling ballast

1 Routine packing, washing vehicles, wheeling trolley down clear gangway

2 Feed press tool (hand clear of press); topping up battery

3 Painting walls

4 Assembling small and simple batches (performed without much thinking);

sewing machine work (automatically guided)

5 Assembling warehouse orders by trolley; simple inspection

6 Load / unload press tool; hand feed into machine; spray painting metalwork

7 Adding up figures; inspecting detailed components

8 Buffing and polishing

10 Guiding work by hand on sewing machine; packing assorted chocolates

(memorizing patterns and selecting accordingly); assembly work too
complex to become automatic; welding parts held in a jig

15 Driving a bus in heavy traffic or fog; marking out in detail with high accuracy

Note: ILO (1992) considers what would happen if the operator were to relax attention,
responsibility, need for exact timing, and accuracy or precision required.
Source: International Labor Office. 1992. Introduction to Work Study, 4th ed. Geneva,
Switzerland: ILO. With permission.

38.6.4 Overview of ILO Fatigue Allowances
The ILO fatigue allowances were developed by a British consulting firm, which did not publish any
detailed justification or explanation of how the values were determined. They give a rational structure
of allowances but the allowances certainly are subject to question.
An important point is that they vary with only the job — not the person. They do not depend on
whether the worker is male or female, age 20 or 60 yr, or weighs 50 or 100 kg.
Another point is the appearance of inadequate ranges for many of the factors. For example, for
posture, sitting easily is 0 points while climbing up and down ladders is 8 points. For monotony, two
people on jobbing work is 0 points while adding similar columns of figures is 8 points. As mentioned
in Table 38.1, a point is not a percentage allowance. At low values of points (say up to a total of 14
points), only a couple of additional percent times are given.
The length of the work time per day, the days per week, and the hours per year are not specified. Pre-
sumably, it is 8 h day, 5 days week, and approximately 1900 h yr. What the allowances would be for

/ / /

longer or shorter times is not given.
The allowances consider recovery from fatigue to be complete by the start of the shift on the next day.
They do not consider the extra recovery time of weekends, holidays, or vacations. In addition, the

TABLE 38.7 Monotony Allowances

Points Degree

0 Two people on jobbing work

3 Cleaning own shoes for 0.5 h on one's own

5 Operator on repetitive work; operator working alone on

nonrepetitive work

6 Routine inspection

8 Adding similar columns of figures

11 One operator working alone on highly repetitive work

Note: ILO (1972) considers the degree of mental stimulation and if there is
companionship, competitive spirit, music, and so on.
Source: International Labor Office. 1992. Introduction to Work Study, 4th ed.
Geneva, Switzerland: ILO. With permission.