5/26/2018 22 Principles of Motion Economy

1/27

1

PRINCIPLES OF MOTION

ECONOMY

IENG 301

FUNDAMENTALS OF

WORK STUDY AND

ERGONOMICS

5/26/2018 22 Principles of Motion Economy

2/27

2

Principles

5/26/2018 22 Principles of Motion Economy

3/27

3

As Related To The Use Of

The Human Body

1. The two hands should begin as well ascomplete their motions at the same time.

2. The two hands should not be idle at thesame time except during rest periods.

3. Motions of the arms should be made in

opposite and symmetrical directions, and

should be made simultaneously.

5/26/2018 22 Principles of Motion Economy

4/27

4

Fig 109 Fig 110

5/26/2018 22 Principles of Motion Economy

5/27

5

Fig 111-113

5/26/2018 22 Principles of Motion Economy

6/27

6

Bolt & Washer Example

Average time per assembly, old method 0.084 min Average time per assembly, new method 0.055 min

Time saved 0.029 min

Increased in output = 53%

Increase in Output in Percent

Pieces produced Pieces producesper min, new method per min, old method

Pieces produced per min,

old method

5/26/2018 22 Principles of Motion Economy

7/27

7

As Related To The Use Of

The Human Body

4. Hand and body motions should beconfined to the lowest classification

with which it is possible to perform the

work satisfactorily.

5/26/2018 22 Principles of Motion Economy

8/27

8

Table 9 Fig 122

5/26/2018 22 Principles of Motion Economy

9/27

9

5/26/2018 22 Principles of Motion Economy

10/27

10

As Related To The Use Of

The Human Body

5. Momentum should be employed to assistthe worker whenever possible, and it

should be reduced to a minimum if it must

be overcome by muscular effort.

6. Smooth continuous curved motions of the

hands are preferable to straight-linemotions involving sudden and sharp

changes in direction.

5/26/2018 22 Principles of Motion Economy

11/27

11

As Related To The Use Of

The Human Body

7. Ballistic movements are faster, easier, andmore accurate than restricted (fixation) orcontrolled movements.

8. Work should be arranged to permit easyand natural rhythm wherever possible.

9. Eye fixations should be as few and asclose together as possible.

5/26/2018 22 Principles of Motion Economy

12/27

12

As Related To The Work

Place

10.There should be a definite and fixedplace for all tools and materials.

11.Tools, materials, and controls should

be located close to the point of use.

5/26/2018 22 Principles of Motion Economy

13/27

13

Fig 130

5/26/2018 22 Principles of Motion Economy

14/27

14

Fig 131

5/26/2018 22 Principles of Motion Economy

15/27

15

Fig 133 Fig 134

5/26/2018 22 Principles of Motion Economy

16/27

16

As Related To The Work

Place

12.Gravity feed bins and containers

should be used to deliver materialclose to the point of use.

5/26/2018 22 Principles of Motion Economy

17/27

17

As Related To The Work

Place

13. Drop deliveries should be used wheneverpossible.

14. Materials and tools should be located to

permit the best sequence of motions.

15. Provision should be made for adequate

conditions for seeing. Good illumination isthe first requirement for satisfactory visualperception.

5/26/2018 22 Principles of Motion Economy

18/27

18

Fig 139

5/26/2018 22 Principles of Motion Economy

19/27

19

As Related To The Work

Place

16.The height of the work place and thechair should preferably be arranged

so that alternate sitting and standing

at work are easily possible.

5/26/2018 22 Principles of Motion Economy

20/27

20

Fig 143 Fig 144

5/26/2018 22 Principles of Motion Economy

21/27

21

As Related To The Work

Place

17. A chair of the type and height topermit good posture should be

provided for every worker.

5/26/2018 22 Principles of Motion Economy

22/27

22

Fig 146 Fig 147

5/26/2018 22 Principles of Motion Economy

23/27

23

As Related To The Design Of

Tools And Equipment

18.The hands should be relieved of allwork that can be done more

advantageously by a jig, a fixture, or a

foot-operated device.

19.Two or more tools should becombined wherever possible.

5/26/2018 22 Principles of Motion Economy

24/27

24

Fig 157

5/26/2018 22 Principles of Motion Economy

25/27

25

As Related To The Design Of

Tools And Equipment

20.Tools and materials should be pr-positioned whenever possible.

21.Where each finger performs somespecific movement, such as intypewriting, the load should be

distributed in accordance with theinherent capacities of the fingers.

5/26/2018 22 Principles of Motion Economy

26/27

26

Fig 158

5/26/2018 22 Principles of Motion Economy

27/27

27

As Related To The Design Of

Tools And Equipment

22. Levers, hand wheels and othercontrols should be located in such

positions that the operator can

manipulate them with the leastchange in body position and with the

greatest speed and ease.