1. Taking body size into account
The height of the worktop surface must
be suitable for employees of differing sizes.
The standard work-stations
are designed for a range of heights that
covers 95% of all adult female and male
sizes.
Specially adapted workstations
are also available.
When selecting the workstation height
you should observe the following:
- Ensure adequate freedom of movement
beneath the desk (for seated/standing
workstations the following applies:
foot room depth > = 550 mm,
leg room depth > = 350 mm).
Avoid obstacles such as drawers between
the upper thigh and the underneath
of the desk surface.
- The size of the workpiece on the desk
influences the employee’s posture.
When carrying out work that is very
demanding on visual monitoring and
the motor functions the working
position should be higher than for
activities that place minimal requirements
on visual monitoring and
demanding requirements on arm
freedom of movement.
- Take up various sitting positions,
depending upon the task of work.
• Forward seating position:
bending slightly forwards
(assembly work that requires
force).
• Central seating position: upright
(assembling small components,
testing).
• Rear seating position: leaning
slightly backwards (testing,
monitoring).
Workstations take account of the differing body sizes
Seated and standing workstations
Visual distances and lower arm positions shown according to varying body height and
working height |
| |
 |
| |
2. Testing the area of reach
A distinction can be made between
three areas of reach at the workstation:
• maximum area of reach,
• optimum area of reach and
• area of reach with both hands.
All components, tools and all accessories
should fundamentally be positioned
within the employee’s reach.
Having
parts within easy access avoids the
need for turning the body, the arms
and bending and twisting wrist joints
when reaching for parts, consequently
reducing extreme stresses and injuries
that occur as a result of one-sided and
repeated movements.
The supply of components should be
planned on the basis of the following
criteria:
• Area A
Do not position grab containers outside
this zone which can be used to
extremely beneficial effect.
• Area B
Parts and tools which are frequently
collected with one hand should be
positioned here.
• Area C
Mountings and containers with the
most frequently used components
should be positioned within this area as
this is where both hands work within
the field of vision.
Area of reach for a woman 1660 mm tall
(woman of medium height). |
| |
|
| |
3. Optimise the layout of parts containers and the material flow
Optimise container layout in order to
reduce superfluous movements and to
speed up the parts flow rate:
• Containers with the most frequently
used components should always be
easily accessible with minimum
movement (within close grasp).
• Heavy components should be located
in lower containers on the work
surface. Reason: it is less tiring to
remove components from the container
parallel to the work surface than to
remove components from an upper
container and place them onto the work
surface.
• Where possible position all containers
within the optimum area of reach B.
• Make use of the facilities for working
with both hands in order to save time.
• Select container sizes to match parts
geometry and quantities.
Pay heed to the area of reach in order to minimise the reach of and the need for the employee to
turn his/her body. |
| |
|
| |
4. Avoid positioning workstations above heart height
Observe the following basic rules:
• Avoid positioning workstations above
heart height, otherwise the blood
circulation will be reduced, resulting in
a rapid drop in the employee’s
performance.
• Avoid tasks which involve static holding
during assembly, otherwise the supply
of blood to the muscles will be reduced
and muscle tiredness will increase. This
in turn will result in a fall in the
coordination capability, one of the main
factors for poor product quality.
• Use seated/standing workstations and
group workstations in order to enable
the workload to be alternated.
Arrange for all work to be carried out below heart height in order to improve the blood circulation
Avoid activities which involve static holding, because otherwise the supply of blood is restricted. |
| |
|
| |
5. Take account of fields of vision
The ergonomic requirements for the field
of vision should be taken into account
for the purpose of optimum workstation
design:
• Avoiding unnecessary head and eye
movements saves the employee having
to repeatedly refocus his/her vision, an
action that puts a strain on the eyes.
• Provide for a natural head position
(when standing 15°, when sitting 25°
angled towards the horizontal).
• Arrange frequently required materials
within the optimum field of vision A
(objects can be easily identified by eye
movement without the need for head
movement).
• Where possible, do not arrange
materials outside the maximum field of
vision C (objects can be identified
without head movement).
• Position the containers at the same
distance. The employee’s eyes will then
not have to refocus on differing
distances each time there is a change
in the angle of vision.
Reduce angle of vision to less than 35° (B)
Limits of the maximum field of vision (B)
Limits of the field of vision expanded by head movement (D) |
| |
|
| |
6. Adjust lighting to suit the task
Proper lighting is extremely important.
The correct lighting for a specific task
reduces errors and increases the
employee’s performance.
A number of
guidelines for adapting the lighting to
suit the specific task are shown below:
For most tasks the standard light intensity is
500 Lux
For specific viewing tasks
1000 - 1500 Lux is required |
| |
|
| |
7. Adjust working aids to correct setting
Desk, chair, foot support, container, tool
preparation, material trolleys and box
lifting equipment settings should be
adjusted to suit the requirements of the
employee and his/her task.
Correctly adjusted working aids reduce
strain and downtimes and simultaneously
increase productivity and performance.
The ergonomically designed components
for workplace
fitting-out form a co-ordinated system.
Utilise the adjustment facilities to maintain
an economic and fatigue-free posture:
• Place components and tools at the
correct height and distance: shorter
access times thanks to closer access
positions.
• Ensure correct chair and foot rest
position: upper and lower thigh should
form a right angle.
• Position movable material trolleys within
reach and angle them in such a way as
to enhance accessibility.
• Use box lifting equipment to avoid
fatigue when positioning heavy
components.
Correct adjustment of the workstation to suit the employee |
Correct adjustment of material trolleys to suit the employee |
|
| |
| |
