Subject: Industrial Engineering And Management

Topic: Work System Design

Difficulty: Medium

i) Illumination :

when human activities are carried out indoors or at night, it is necessary to provide some sort of artificial illumination the type of lighting or illumination depends upon the type of work being performed, the size of the objects, accuracy, speed and duration of the work, etc.

The lighting system should provide

• Sufficient brightness.

• Uniform illumination.

• A contrast between brightness of the job and of background.

• No direct or reflected glare.

ii) Vibration :

Usually vibrations of the air are detected as sound but air vibrations below 20 Hz are not heard but can be felt. Vibrations can affect the performance on target tracking. Ideally vibrations should be minimized at sources. Normally protection from residual vibration is achieved by reducing the forces transmitted, by converting vibration energy into thermal energy by using mechanical or hydraulic dampers and by altering body position and body support.

iii) Thermal conditions:

Poor heat and humid conditions produce thermal stresses in the workers which affect their efficiency, concentration and dexterity of their members of the body. Working temperature of 60-650 F is considered as normal but it varies according to the nature of work. Humidity and heat are related to each other both affect comfort and tolerance of the body to the heat. If humidity is high, evaporation of the sweet is reduced which results in dryness if mouth, throat and nose.

Humidity as a general rule should not be allowed exceed 70%. The effect of heat can be minimized by:

• Shielding, isolating heat sources to reduce direct transmission by radiation of heat between body and the heat source.

• Installation and provision for adequate local ventilation to get rid of smokes, fumes, etc.

• Permit rest pauses in cool, extreme hot conditions.

iv) Ventilation:

Ventilation is the process of displacement of state air of the building by fresh air to reduce the presence of bad odour, CO2 concentration, humidity and temperature.

A good ventilation system provides fresh air.

Most common methods of ventilation are: • Windows and ventilators provide natural ventilation.

• Exhaust fans extract stale air and creates low pressure area to be filled by fresh air.