hfe practicle final

MEHRAN UNIVERSITY OF ENGINEERING &

TECHNOLOGY JAMSHORO SINDH

HUMAN FACTORS

ENGINEERING

NAME: MOHAMMAD YOUNUS

ROLL NO: 08IN70

DEPARTMENT OF INDUSTRIAL ENGINEERING AND MANAGEMENT

Prepared by MOHAMMAD YOUNUS (08IN70)

PRACTICAL JOURNAL

OF HUMAN FACTORS ENGINEERING

CERTIFICATE

It is to Certify that Mr. / Miss: ………………………………………………………………… bearing roll no:

…………………………….. has carried out the necessary practical works as per course of studies of the subject

……………………………………………………….. For the year ………………………. as shown in the practical

schedule of this journal.

Professor In charge ………………….

Department of ………………………..

Date …………………………………..

Head of the Department ………………



CONTENTS

S.NO.

OBJECT

PAGE

NO.

01. Observe the effect of environment on the performance of human body. 04

02. To observe that how the work place i.e. sitting and table height affects the

performance of human being. 06

03. Effects of work load on the performance of human body. 09

04. How the man-machine interaction can be enhanced while designing the product. 12

05. Prove that the user performance decreases with the increasing noise. 13

06. How illumination is measured and what are its methods. 15

07. Suggest the best numeric keyboard and structure for calculator / telephone. 17

08. Suggest the different seating arrangements for male and female students according

to their ages and dimensions. 19

09. Measure the position of eye using terminals. 23

10. Suggest the best arrangements of components within a physical space. 25

11. Suggest the best criteria and counting the information/ speech. 27



PRACITICAL # 1

TITLE:

Effects of the environment.

OBJECT:

Observe the effect of environment on the performance of human body.

EQUIPEMENT:

Room thermometer, computer, stop watch, machine lab ceiling fan, and pc lab. And different

locations.

THEORY:

According to human factors engineering, it is assumed that “The environment (i.e.

temperature, illumination, humidity) affect the performance of human body.”

DESCRIPTION:

Many occupation and task expose implies to hot or cold working environment it is important

to distinguish between a condition which threatens health and safety and a feeling of discomfort.

Thermal discomfort may be experienced even there is a little likely hood of medical

condition developing. For example, office workers may feel uncomfortable if there air conditioning

is not working to optimum effect in hot weather, which could result in a real risk of heat related

illness which may create a serious threat to health. Preventive step should aim to reduce thermal

discomfort as much as is practicable and to develop working condition and work practices which will

not give rise to more serious problems.

PROCEDURE:

To prove the above statement following experiment was conducted in human factors

engineering laboratory. The main elements of experiment were :

1. A group of four students was chosen per experiment.

2. Every student was given the same 30 minutes to type on computer.

3. Every student was provided with different environment conditions i.e. temperature.

4. All students were kept in close supervision.



5. The temperatures were manipulated.

OBSERVATION: Refer the table below

S.No Written

article

Time

given Temperature Experience

Errors in

writing

Level of

performance

1. Introduction

to H.F.E 30 minutes Too high 2-yrs 200 Very poor

2. Same 30 minutes Too low 2-yrs 195 Poor

3. Same 30 minutes Moderate 2-yrs 180 Good

4. Same 30 minutes Room

temperature 2-yrs 150 Very good

RESULTS:

From the above experiment it was concluded that the human performance is affected by the

environmental conditions

Standard temperature for the office work is suggested around 20 to 24 o C and 30 to 60 %. It does

not mean that the work could not be done beyond this temperature range. Similarly is the case with

other factors such as, illumination, noise, humidity etc. causing human performance to be decreased

air temperature can cause sweating, dizziness, muscle cramps, shivering, hypo-thermia etc. humidity

can cause discomfort, flushed skin, headache, vomiting etc.



PRACTICAL # 2

TITLE:

Improper work place.

OBJECT:

To observe that how the work place i.e sitting and table height affects the performance of

human being.

REQUIREMENTS:

Computer, different chairs, different table size, PC lab, stop watch.

DESCRIPTION:

Different people have different physical dimension and required different sort of chairs and

table regarding comfort and ease so has to maximize the performance in the work place.

PROCEDURE:

To prove the above statement following experiment was conducted in human factor

engineering laboratory. The main elements of experiment were:

1. A group of four students was chosen per experiment.

2. Every student was given the same 30 minute to type on computer.

3. Every student was provided with different sizes and types of chairs and table and also tasks to

work with.

4. All students were kept in closed supervision.

5. All students were interviewed to know their view.



Feeling fatigue and pain in legs due to hard position

OBSERVATION: Refer the table given below

MALE FEMALE Type of task

(seated) Inch cm inch Cm

Fire work 39.0-41.5 99-105 35.0-37.5 89-95

Precision work 35.0-37.0 89-94 32.5-34.5 82-87

Light assembly 29.0-31.0 74-78 27.5-29.5 70-75

Coarse/medium

work 27.0-28.5 69-72 26.0-27.5 66-70

Reading and

writing 29.0-31.0 74-78 27.5-29.0 70-74

Range for typing

desks 23.5-27.5 60-70 23.5-27.5 60-70

Computer

keyboard use 23.0-28.0 58-71 23.0-28.0 58-71



CONCLUSION:

Form the above practical we concluded that before designing any type of chair or table

following point should be kept in mind.

1. For whom we are designing.

2. The work for what it will be used.

3. The environment where it (chair/table) will be used.

4. The color of the chair.

5. The ratio of flexibility etc.

Thus we conclude that for designing any chair or table we have to satisfy a large number of user

populations so as to provide comfort and ease with great degree of flexibility.



PRACTICAL # 3

TITLE:

Workload.

OBJECT:

Effects of work load on the performance of human body.

REQUIREMENTS:

Working environment and stethoscope.

DESCRIPTION:

There are many factors that contribute to the work load experienced by the people while

engaged in physical work. Astrand and rodahl (1986) presented the major factors that influence the

body energy level of output.

The factors include: nature of work, somatic factors, training, motivation and environment.

These influence the energy output level through the physiological service function of supplying fuel

and oxygen for muscle metabolism.

Efficiency (%) = Work output x 100

Energy consumption

PROCEDURE:

1. Students are made to perform different types of work such as pulling or pushing the carts etc.

2. After performing the task, heart rate was calculated at worm up position.

3. Energy consumption is also calculated.

4. In last, conclusion was made regarding the students fitness for particular work.



Feeling fatigue and pain in limbs Feeling fatigue while doing

due to heavy load work due to work load

OBERVATION: Estimated work efficiency for various activities.

Activity Efficiency

Shoveling (stooped posture) 3

Shoveling (normal posture) 6

Using heavy hammer 15

Going down and up stairs 23

Pulling a cart 24

Pushing a cart 27

Cycling 25



Grade of physical work based on energy expenditure level.

Grade of work Energy

expenditure(kcal/min)

Energy

expenditure

Heart rate

(beats/min)

Oxygen

consumption

(L/min)

Rest (sitting) 1.5 >720 60-70 .3

Very intense

work 1.5-2.5 768-1200 65-75 0.3-0.5

Light work 2.5-5.0 1200-2400 75-100 0.5-1.0

Moderate work 5.0-7.5 2400-3600 100-125 1.0-1.5

Heavy work 7.5-10.0 3600-4800 125-150 1.5-2.0

Very heavy

work 10.0-12.5 4800-6000 150-180 2.0-2.5

Un-duly heavy

work >12.5 >6000 >180 >2.5

RESULT:

Knowing the heart rates and energy consumption, performing different task, it can be

concluded that which job is suitable for the user.



PRACTICAL # 4

TITLE:

Man-machine interaction.

OBJECT:

How the man-machine interaction can be enhanced while designing the product.

REQUIREMENTS:

Two students, two computers (one black & white and one colored), written specimen, proper

elimination, temperature and seating arrangement.

DESCRIPTION:

For the better performance of the user at work, it is important that the work area should

possess the quality to match man and machine and it can be improved by making the machine more

user friendly.

PROCEDURE:

To prove the above statement, following experiment was conducted. The main elements off

experiment are as under.

Two students were selected, provided the same illumination, temperature, working area, typing

experience and written specimen.

One student was provided the colored pc while other black & white.

Both were given one hour to type on their respective pc.

Both students are kept in close supervision.

Both were interviewed by supervisor at the end of experiment.

OBSERVATION:

From above experiment following results were derived.

1. Student with colored pc wrote more words than that of having black & white pc.

2. Student having colored pc had better visualization.

3. Colored pc student had less eye and mental fatigue.

4. Student with colored pc was more will to do work.



PRACTICAL # 5

TITLE:

Noise.

OBJECT:

Prove that the user performance decreases with the increasing noise.

REQUIREMENT:

Lathe machine, sharper machine, drill machine, grinding machine, students and work

specimen.

DESCRIPTION:

Noise is such type of sound which creates irritation and can result performance reduction.

PROCEDURE:

Following procedure was adopted to prove the above statement.

1. All mentioned machines were operated and caused noise at the level of 9000 Hz.

2. Students were assigned to work on lathe, shaper, drill and grinding at same time.

3. After 15 minute, the performance was checked and evaluated.

4. Now lathe machine was stopped while the other machines were let to work with the reduced

level of noise to 8000 Hz.

5. After another 15 minutes, the performance was checked and evaluated.

6. This time sharper and drill machines were stopped while grinding machine was continued to

work with the reduced level of noise to 6500 Hz.

7. In same way, the performance of students was checked.

OBSERVATION:

1. The operation must be given protective devices while working in noisy environment.

2. There must be provision of ventilation in workplace so that most of the noise can be

absorbed.



3. The base of the machine should produce less vibration.

4. The work area and building must be designed in a way that there is no echo in building.

5. Proper maintenance of machine can also result in noise reduction.

Feeling irritation while doing work due noisy environment

RESULT:

1. As the machine operation was stopped, the noise was reduced and lead to the better

performance.

2. The finished product came up with better quality.

3. The decreasing noise also enhanced the degree of better communication among the students.

4. The students were feeling less fatigue as the machines were stopped one by one.

5. The decreased noise can result in better quality and performance of the students.



PRACTICAL # 6

TITLE:

Illumination.

OBJECT:

How illumination is measured and what are its methods.

REQUIREMENTS:

LUX meter, artificial light (candle), measurement tape, paper and pencil.

DESCRIPTION:

Illumination includes both artificial light source such as lamps and natural illumination of

interiors from daylight. Illumination represents a major component of energy consumption,

accounting for a significant part of all energy consumed worldwide.

Artificial illumination is provided today by electric lights, but previously by gas lighting candles or

oil lumps. Proper lighting can enhance task performance or aesthetics; while there can be energy

wastage and adverse health effects of lighting.

It is valuable to provide the correct light intensity and color spectrum for each task or

environment. Otherwise, energy not only could be wasted but over-illumination can lead to adverse

health and psychological effects.

Specification of illumination requirements is the basic concept of deciding how much

illumination is required for a given task.

PROCEDURE:

Following is the procedure for conducting this practical by putting LUX meter in vertical and

horizontal position.

1. First we check the room/lab illumination , i.e 50 lux

2. Mark the starting and ending point from 0 to 12 inches respectively.

3. We place the candle at 12 inches away from the lux meter.



4. After that we remove the lux meter towards the candle with equal distance of 1 inch and

record the reading.

READING:

Reading available in the room/lab in vertical = 150

In horizontal = 175

Candle height = 4”

Lame = 2”

Position of LUX meter

Horizontal Vertical Candle

200 300 12

250 150 11

200 250 10

300 300 09

325 250 08

300 350 07

350 375 06

400 450 05

450 800 04

550 700 03

350 1000 02

400 1700 01

RESULT:

From the above recorded data, we conclude that the distance that the distance from source

decreases the illumination.



PRACTICAL # 7

TITLE: Best numeric keyboard.

OBJECT:

Suggest the best numeric keyboard and structure for calculator / telephone.

INSTRUMENTS: Telephone set (digital), calculator, stopwatch, pencil and paper.

PROCEDURE: To suggest the best arrangement of keys on both telephone and calculator, first we have to

examine the existing structure of both.

CALCULATOR CALCULATOR

(Standard Model) (Suggested Model)

% OFF ON

R-ME M+ M- /

7 8 9 .

4 5 6 *

1 2 3 -

CHECK % OFF ON

R-ME M+ M- /

7 8 9 X

4 5 6 -

1 2 3 +

0 . = ANS



TELEPHONE TELEPHONE

(Standard model) (Suggested model)

S. No Model type Number dialed Duration (seconds)

1 Standard 0313-3167888 5.00

1 Suggested 0313-3167888 6.75

2 Standard 0313-3167888 4.5

2 Suggested 0313-3167888 7.00

1 2 3

4 5 6

7 8 9

* 0 #

# 0 *

3 6 9

2 5 8

1 4 7



PRACTICAL # 8

TITLE:

Seating arrangement.

OBJECT:

Suggest the different seating arrangements for male and female students according to their

ages and dimensions.

REQUIREMENT:

Measuring tape, vernier caliper, scale, paper and pencil.

DESCRIPTION:

Diverse evidence from many cultures shows that sitting has been associated with numerous

problems: back pain of all sorts, fatigue, varicose veins, stress and problems with the diaphragm,

circulation, digestion, elimination, and general body development.

PURPOSE:

According to Cranz and other radical ‘somatic’ practitioners who practice ‘new ergonomics’

is that we have been forced into a ‘table’ and ‘chair’ culture. Where many activities take place in a

right-angled seated position. This position forces the body into a C-shaped slump and this places

uneven pressure on the vertebral disks of the lower back. With time, the spine can become deformed

and erode disks.

Adjusting the fit, title, and height of your chair is very important for proper posture and

comfort. The backrest of the chair should have a snug fit against your back. Every chair is different,

but in general, looks for height, lumbar support, and tilt adjustments. If you find that you need

additional lumber support, a back cushion can be used to customize your chair. Adjust your seat tilt

so you are sitting up right with your feet firmly on a surface and your lower back well supported. Set

chair height so that your hands and wrists should remain at the same level as the home row on the

keyboard. If these adjustments cause your feet to dangle, you’ll need a foot rest.

PROCEDURE:



Firstly, we choose a student of height 5.8 feet among all the students. We started taking

measurement.

1. Inner side of the foot = 9.5”

2. Foot to knee = 18.5”

3. Thigh to lumber lord sis = 23.0”

4. Waist = 33.0

5. Lumber lord sis shoulder = 27.0”

6. Shoulder to head = 13.5”

After taking all the measurements, we suggested the following dimensions of the computer

chair for the students. The dimensions are:

1. Height of the seat = 17.0”

2. Thickness of the seat = 2.0”

3. Width of the seat pan = 17.5”

4. Height of the back rest = 18.0”

5. Width of the back rest = 17.0”

6. Angle of the back rest = 1000 - 1100

“I love my ergonomic office chair. It

reclines, has heated vibrating massage,

and provides electro-shock therapy at the

end of a stressful”.



RESULT:

1. Students were feeling more comfortable.

2. They were not feeling back ache after sitting for more than an hour.

3. The recommended height of the chair improved the typing performance because the

suggested dimensions gave proper compatibility of arms and keyboard.

4. Due to proper height of the chair, the leg swelling was reduced up to 50%.

STANDARD ADJUSTMENT TO BE MADE:

Start our adjusting a chair from the ground up. Start with the height and move up from there.

While adjusting the chair, worry first about getting the chair adjusted to fit you. Afterwards, look at

things like the height of the desk, keyboard etc. Too often, people adjust a chair too high so they can

reach the keyboard rather than properly adjusting the chair and adding a keyboard tray to move the

keyboard to the correct height.

SEAT HEIGHT:

Start by adjusting the height until your things are parallel to the floor, stand in front of the

chair and adjust the height until the top of the seat pan is at the height of the bottom of your kneecap.

Then, sit in the chair and make small height adjustments until your things are parallel to the ground.

Sit in this position for a while before making any further changes in seat height. When you have



become accustomed to this height, adjust the chair height up/down 1-3 inches until you find a

location that is comfortable for you while seated (don’t worry about that keyboard height yet!).

SEAT DEPTH:

Adjust the seat pan until you have about three fingers to a fist’s width of room between the

back of your calf and the front edge of the chair when your back is touching the backrest. If the seat

pan is not adjustable and the pan is too deep, add padding to the backrest (a towel over the backrest

of the chair or a backrest cushion) to shift you forward in the seat while maintaining contact with the

backrest. If the seat pan is too shallow, start looking for a new chair.

SEAT ANGLE:

There are three basic postures. The standard posture calls for a level seat pan so it is not

necessary to adjust the tilt for this posture. Likewise, the reclined posture can have the seat flat as

well. However, some people prefer to have a very slight backward tilt on the seat pan to help keep

them in the seat. In the forward tilt posture, the seat pan is tilted forward 5-100. start by raising the

overall height of the chair a few inches, and then tilt the seat pan forward.



PRACTICAL # 9

TITLE: Vision and eye.

OBJECT: Measure the position of eye using terminals.

THEORY: The eye is a fluid membranous sphere which converts the electromagnetic radiations into

nerve impulses. It is very sensitive organ of human body. It consists of nine parts working differently

from each other.

1. Cornea.

2. Pupil.

3. Lens.

4. Iris.

5. Suspensor ligaments.

6. Retine.

7. Foveae.

8. Blind spot.

9. Optic nerve.

PROCEDURE:

Light enters the eye through a transparent outer covering called the cornea. The cornea plays

very important role in reflecting the incident light. Further reflection occurs as the light passes

through the lenses. During the working on the places where terminals are use then person always try

to sit at keep distance because when we use the rules then we do not feel fatigue earlier. The standard

distance of terminal from human eye is 20-25 inches and the position of the eye is 7-10 inches from

center. These are the standard and by using these rules we reduce the human eye fatigue.



OBSERVATION:

Distance from eye to

terminal (inches)

Height of terminal

from center (inches)

Height of eye from

sitting posture (inches) Illumination

15-20 2-5 20 Normal

20-25 7-10 24 Standard

30-35 10-13 28 Low



PRACTICAL # 10

OBJECT:

Suggest the best arrangements of components within a physical space.

REQUIREMENTS:

Stop watch, set of different components and drill machine.

THEORY:

Working safety begins with looking at the physical arrangements of your work space and

design of the tools you use. This draws from the science of ergonomics which strives to fit the work

to the body rather than forcing the body to conform the work. As logical as this may sound, it is

actually a pretty view.

Ergonomics is being abused as marketing term, being thrown as easily as the word “natural”

is with food. Suddenly every thing is “ergonomically designed”. A product will not be very

ergonomic for someone if it is not used in the right way for the right purpose. And since many

ergonomic products are adjustable, it takes training to take advantage of what they have to offer.

Otherwise they can be just as uncomfortable or injurious as your old furniture.

One of the most common scenario seen today is the company which buy new furniture with a

wide range of adjustability but does not teach its employees how they operate or in what principles to

adjust them. There are examples of companies where cumulative trauma problems increased after

installing ergonomics furniture. Imagine their surprise! The answer is training.

You need to understand the principle behind ergonomics design. It is really very simple. The

goal is to prevent unnecessary muscular efforts, and avoid postures which put strain on the body. In

short, to make you comfortable.



Maximum and minimum reach at work station

PROCEDURE:

For the drilling purpose, the major components required are

1. Drill bits

2. Cutting oil

3. Job

The drill bits should be placed alongside the machine so that they can easily be reached.

The cutting oil is required during the drilling process and should be provided with in the form

of pipe pouring the oil continuously on the job.

The height of the machine should be suitable and proportionate to the size of the worker

because it is too high, the worker can not reach it and if it is too low, the worker will have to bend,

including a lot of fatigue.



PRACTICAL # 11

OBJECT: Suggest the best criteria and counting the information/ speech.

THEORY:

In the process of designing the speech communication system, one needs to establish the

criteria or standards the system should need to be acceptable for the interred uses. Criteria are also

required to evaluate the effects of noise and ear protectors on speech communication and to measure

the effectiveness of hearing aids. The major criterion for evaluating a speech communication system

is intelligibility, but there are others as well, including quality or nature less of the speech.

SPEECH INTELLIGIBILITY:

Intelligibility is simply the degree to which a speech message (e.g. a list of words) is

correctly recognized. Intelligibility is assessed may transmitting speech material to individuals who

are asked to repeat what they hair or to answer question about what they hair. Various speech

intelligibility tests exists which differ in terms of types and materials presented “ example : nonsense

syllables politically balanced (PB) words list that contain all the various speech, sounds and

sentences “ In general, in a given situation, intangibility is highest for sentences, lessees for isolated

words and lowest for nonsense syllables.

SPEECH QUALITY:

Speech quality or naturalness goes beyond intangibility. It is important in situation where it is

desirable to recognize the identity of speaker such as on the telephone. Speech quality is also

Important as one determinate of user satisfaction with a communication system, for example: mobile

telephone for auto mobiles have become relatively in expensive and available. In telephones, for the

home that allow a person to talk and hear from any where in the room “Called speaker phone” are

also popular, automatic telephone, answering machine are also be coming common in all these cases.

The quality of speech heard over the system often the critical factor that accounts for the purchase of

one system over another.



Speech quality is defined in terms of preferences usually samples of speech are presented

over the system and people are asked to either rate the quality (excellent, fair, poor, un-expectable).

This type of methodology is often used to evaluate synthetic speech as well.

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