Welcome to the course digital human modeling and simulation, for virtual ergonomics evaluation.

So, in this course, the course digital human modeling and simulation for virtual ergonomics

evaluation, deals not only with the basic ergonomics, but also covers all the relevant

topics, related to virtual ergonomics evaluation techniques, including its advantages and disadvantages.

So, now, intended audience, for whom this course has been designed. This course is for

undergraduate and post graduate students of engineering, then industrial design disciplines.

It is expected that engineering students of undergraduate and postgraduate departments,

from various background like mechanical engineering, production engineering, then civil engineering

who are also studying biomedical engineering, all of them will be immensly mostly benefited

from this course. Not only engineering students, but also students who are studying industrial

design, as well as architecture or various course related to occupation health and safety,

they will also find this course very interesting and also beneficial for their curriculum.

Now, this course is mainly elective course and who can opt for, already mentioned both

undergraduate students and post graduate students can opt for this course but one, there is

one prerequisite for digital human modeling and simulation for virtual ergonomics evaluation.

If you want to learn this course, you want to know about this course, then what is the

prerequisites? Prerequisite is the, you must have basic knowledge of any 3D modeling CAD

software, that may be UNIGRAPHICS, that may be CATIA, that may be SolidWorks , but at

least one of the 3D CAD modeling software you must know. If not very proficient no problem,

but basic knowledge of any 3D CAD modeling software is essential for this course.

. Now, the course we have made like this way,

in particular, this course will run for 8 weeks and in different weeks, we will discuss

different topics. So, it will start from introduction to ergonomics in the first week, and then

gradually we will move towards digital human modeling so that in the second week use of

percentile anthropometric and biomechanical data for designing various facilities or workstation

or products we will discuss, then in the third week, we will discuss about virtual ergonomics

and its advantages. In the fourth week, introduction to digital human modeling and simulation,

then in week 5, techniques or methods of virtual ergonomics evaluation using digital human

modeling software. The same will be continued in week 6. And

in week 7, we will discuss how this digital human modeling software is used for virtual

ergonomics evaluation, across diverse industrial sectors or occupational sectors. And in the

last week, that is 8th week, we will discuss about the future research flow in this direction

and what steps or what initiative is needed to be taken, to popularize this subject and

popularize this domain of knowledge in developing countries like India. Now, moving to the course,

we are starting today the first module; module one, and this module is related to introduction

to ergonomics.

. Before moving to

the actual topic, that is digital human modeling and simulation for virtual ergonomics evaluation,

we should discuss something related to design, then gradually we will move to ergonomics,

then virtual ergonomics and digital human modeling. Because, as we are studying virtual

ergonomics. For studying virtual ergonomics, knowledge of ergonomics is required, first

you know by the contextual knowledge of ergonomics, second is the design. You must know that,

how we use ergonomics in designing various products or work place or different types

of facilities. If you see this statement by Dukic et al. (2002), he mentioned contextual

knowledge is strongly recommended for virtual ergonomics evaluation or virtual investigation,

using CAD and Digital Human Modeling software. So, this is very important that contextual

knowledge, in which context we are evaluating the product of or facility, using our software

CAD modeling, CAD software that is very important. And the second important thing is that knowledge

of ergonomics is very important for that purpose. So, while someone is going to learn digital

human modeling software or want to use digital human modeling for virtual ergonomics evaluation,

he or she must have the knowledge of ergonomics, otherwise interpretation will go in wrong

direction. Now, in this course we are starting from design.

Now, very interestingly Pheasent (1986), mentioned that there are common five fallacies regarding

the design, that how we should design. Some people think if we design, the design is satisfactory

for me, it will therefore, satisfy everyone, but it is not possible in the real scenario.

People also believe that if design is satisfactory for the average person What is average person?

The person with average body dimension, average capacity of working and is whose all other

average performance capability, then the product will satisfy everybody, that is also not true.

Similarly, the variability in the third, understanding or belief is that, in human population there

is huge variation. So, it is or not at all possible to design any facility or any product,

which will satisfy everybody, but since people are wonderfully adaptable, it does not matter,

what you are designing. So, it means some of the people will adapt it.

The fourth design fallacy is that ergonomics is expensive and since products are actually

purchased based on its appearance or visual aesthetics, so, it does not matter whether

ergonomics principle has been incorporated in the product or not. The fifth fallacy is

that ergonomics is an excellent idea, but I always design things with ergonomics in

mind but I do it intuitively and rely on my self-understanding, I do not need table of

data. It means many people thinks ergonomics is the common sense. So, whatever we can do,

we apply our common sense; that is the ergonomics. For that purpose more database or standard

is required, but that is also wrong. So, these are the five common design fallacies is which

are believed by the people, it has been mentioned by Pheasent (1986).

. Now, if we will ask you, what is design, the

definition of design is varying defining design is very difficult, because sometimes people

will say it is a noun, it is a verb, it is an adjective, but what actually design is,

if I say for example, if we say that design of this, I have a design in my mind for this

pen or I want to design a pen and I have some concept in my mind. So, design sometimes;

it is the concept, sometimes I want to design a chair what does it mean. It means I want

to make some chair; that is the process, I want to follow some processes. Sometimes design

may be, I like the design of the chair what does it mean, design mean that product. So,

sometime design is the product, sometimes design is the process, sometimes design is

the concept or idea. So, actually defining the word design is very difficult.

So, for that reason Heskett (2005), he nicely mentioned what is design. Design is to design,

the design of a design. Now if you notice the color coding, what is design. Design is

general concept or policy, it is an activity, design is a plan or intention or concept and

the last this, green design, the finished product or outcome. So, in general how we

can define design. So, we can define design, as design is, design is a scientific branch,

hire where a particular product or facility or output is developed or made following some

methods, from pre-defined ideas, means design is a process where we are making something,

following some specific process from the pre-concept ideas. Now, why design is important, because

here this is the course for virtual ergonomics, in this course, why we are discussing about

design, because design is very important in our daily life, if you see this diagram, then

what you understand. So, here is origin, importance of design,

origin of cost and here potential to influence the cost. In the typical design development

process, it is starting from design then fabrication then assembly and remaining activities. The

first phase; that is the design. For designing any product or any facility what is required,

only 12 percent origin cost is there, origin cost only 12 percent means, out of hundred

only 12 is required for this purpose but the design is such an important phase in the design

development process, that it has the potential to increase the cost by 75 percent. So, although

in the design phase first cost requirement is very less but if your design is not proper

or correct then what will happen. It will increase the cost by 75 percent. So, design

is a very important phase in the product or process development cycle.

. Now, Nobel Prize winning economist, Herbert

Simon, he defined design, how will I he has defined design. Design is the process we use

to change whatever existing; you will have to make it better. So, that is why he mentioned

design is a the process we use to change the existing scenario, existing situation to the

preferred situation. Now in design process, there are various phases, pre-conceptual phases,

then conceptual, then pre-designed and finally, detailed design. So, these are the four stages

in the design process. So, what we do; pre-conceptual stage, then conceptual. In conceptual stage,

which it is very clear from this second one, conceptual stage. So, we are conceptualizing

or we are going for some ideas for that product, or the facility or that process. Then we are

going for designing, pre-design stage, but what is pre-conceptual, means; before that

conceptualization, what we are going to make, for that concept, before we need some information

to conceptualize the product for that process. So, this will be much more clearer if we go

to the next slide.

So, in pre-conceptual, say for example, we are going to design something for that purpose,

what we need, in the pre-conceptual stage, we need to go for user study or the ethnographic

study, means who are the actual user or intended user, but either, who they are presently using

that type of product, or you are developing some new product which intended user will

use. Next field observation or for market survey, then design limit selection. This

is very important, because before conceptualization of that product you need this information,

means what is the used context, what the targeted user, physical dimension of that product or

facility, material cost, manufacturability, sustainability.

All this information you must have with you, then only you can move for the conceptual

phase. Then in the conceptual phase, ergonomics should be considered from this phase onwards,

not like that in the detailed design phase. So, role of ergonomics is actually starting

from this conceptualization phase. So, first we should go for brainstorming, then focus

group study, conceptualization, then 2D sketches, 3D sketches, then rendered CAD modeling, rendering,

concept screening or finalization, using various techniques like quality function deployment,

analytic hierarchy process. So, many other techniques are there. So, with

those techniques, we can screen those concepts and we can go for mock up development if it

is required so. So, starting from pre-conceptual phase, gradually move towards conceptual phase.

After conceptual phase, while your concept is ready and following that concept screening,

you are entering a in pre-designed phase. In pre-design phase what you are doing. We

are doing ergonomic evaluation in virtual environment, if we have already developed

the 3D CAD model and rendered CAD model. So, we can go for virtual ergonomics evaluation,

using CAD and digital human modeling software. Then we can go for physical mock up development,

if required, then various types of engineering evaluation like material, properties, stress-strain

strength, structures, stability, integrity, manufacturability.

All these issues we can study here. Following this pre-design phase, then we can. So, ultimately

here only we are gathering the information what are required for a conceptualization.

Then in the conceptual phase, we are making the concept, making the following concept

screening, we are finalizing the concept in pre-design stage, mainly we are developing

either CAD model or physical mock up. After that we are going for prototype development.

Very important thing in pre-design stage, what we discussed about, either physical mock

up or virtual mock up or CAD model, in this case these are. So, as we mentioned, this

is mock up, but here it is prototype. So, what is the difference between mock up and

prototype? In mock up generally what we do. We make the product in its miniature form

or scale-down model and the material may not be the original one.

Its functionality may not be like the actual product, actual intended product but in case

of prototype it is material, is also the same like the actual product. It is usable, its

function is similar to the original product for intended use, and the generally prototype

is made in one is to one scale, means. Prototype is made with the actual size, but in case

of mockup we can make any scale-down model for our visualization, for understanding.

Now, in the detailed, now we are again coming to detailed-design phase. In detailed-design

phase, from this mock up, while we are developing the prototype or allowing CAD model, we are

developing the prototype, then prototype is tested, user feedback is taken and ultimately

we move towards final product development or production process. So, here we have given

one example. In this example, so, this is called mopper, for floor cleaning, when we

are cleaning the floor, for that purpose we use this type of mopper.

Now, first we need the information who are using, then what is the dimension, what is

the size, what is the affordability of the people who are using this type of mopper;

that is important in this phase, then gradually while we are moving to conceptualization phase.

Then we are going for 2D sketches, with paper pencil and ultimately developing the CAD model.

While CAD model is ready, then we are making physical mock up CAD model, following CAD

model ergonomic evaluation or engineering evaluation are ultimately, we are coming with

this type of mock up development, when mock up is ready, then after testing of that mock

up, we can go for final production, we can go for prototype, even in this prototype development

phase also we can go for prototype one, refinement of that , then prototype two, then prototype

three, and ultimately we go for production.

. So, just going back, we started from this

slide, if we look at this slide. So, we started from design, then as we mentioned gradually

we will move towards ergonomics. So, first slide we have covered design. What is design,

what are the steps in design, why design is important. Now we are moving to ergonomics.

The word ergonomics is derived from Greek word ergon, meaning work and nomos meaning

law. So, in general we can say, what is ergonomics. Ergonomics is the law of work or principle

of work. There are various definitions of ergonomics. Ergonomics is fitting the task

to the person, use the rule of work, works smarter not harder, then makes things user

friendly, more useable, more comfortable. Here I want to mention one interesting thing.

This is from Linkedin post made by Dr. Era Poddar in 2016. This is very interesting.

I will suggest all of you to go through this one, already link is given. So, she mentioned,

does ergonomics means only a chair, because among various myths about the ergonomics,

the most popular one is, possibly ergonomics is nothing, but a chair. Still now in developing

countries, as well as in few developed countries ergonomics as a subject is not that much popular

and people are unaware about this subject. So, whenever we ask someone what is Ergonomics,

they reply something like, this is something related to comfort, user friendly and generally

how we can make chair table all these. So, that is why, see rightly pointed out that

most popular myth regarding ergonomics, is ergonomics is nothing, but a chair. People

often assume getting an ergonomic chair at the office will solve all the problems related

to that work place, like back pain, repetitive strain injury or any form of musculo-skeletal

disorder but in reality it is far from, that because ergonomics is not only that comfort

or sitting or designing of that chair for that work place, ergonomics gives us, so many

other factors. So, such just example, even this case only, is not only office chair,

while we are talking about the office ergonomics, it is related to hierarchical structure of

that office, then physical environment where that person is working in that office, is

his cognitive work load, how much information he is receiving and how much physical activity

or mental activity he has to do. So, so many other aspects are associated with this, but

people’s only understanding is as , what is ergonomics. Ergonomics is only comfortable

sitting posture or chair table design.

. Now, as we have discussed the definition of

ergonomics that if we ask you him. We have Here are two scenarios, this is scenario one

on the left side, and on the right side scenario two.

. So, which one is preferred? In the first scenario,

one lady, she is in squatting posture, sitting on the ground and cooking on chulla or stove.

On the other hand, in the right hand side, lady is standing and cooking on an elevated

surface. Now if we look at these two pictures. What happened in this case? This is the task

and we force that human that fit the man to the task. So, human is bound to be fitted

with the task, even he is bound to be fitted with the task means fit the man to the task,

this scenario. And on right side as per human requirement, human comfortable posture, the

task has been modified; fit the task as per the requirement of human. So; obviously, between

these two we will prefer for this one. This is the right one, means as we discussed about

the ergonomics. Ergonomics is fitting the task, we have to fit the task to the man,

but never, we compel the man or women to be fitted with the task.

Now, if we elaborate the definition of ergonomics, more elaborately what we can say about ergonomics.

Ergonomics in a single word, what is ergonomics - Ergonomics is an interaction; Interaction

of what, ergonomics is an interaction between human and his or her machine tools or equipment,

ultimately we can mention work elements. So, this is; ergonomics is an interaction between

human and his or her work elements. Now more elaborately we can mention, ergonomics is

a discipline or subject or science, where we discuss interaction between human and work

element. And this is a two-way interaction and this interaction is being influenced by

surrounding physical environment. Not only physical environment, there are so many other

factors also. This interaction is influenced by environmental factors, various environmental

factors like temperature, humidity illumination. Similarly psycho-social factors, various types

of economic factors. So, many factors are there, which are affecting

this interaction. Then, how we can mention the definition of ergonomics, ergonomics is

a discipline or a subject or a science, where we discuss about the interaction between human

and his or her work elements and all other factors, which all other factors, which are

those factors, which affect this interaction. Why we study this subject. To improve, enhance

the performance and efficiency of what, performance and efficiency of the system. Now the thing

what is system. This human; I will just put number one, work elements that is two, and

surrounding physical environment three. Man, machine and surrounding environment. These

three components are collectively forming overall system.

So, man, machine and environment; these collective systems. That system’s performance, efficiency,

is enhanced, if we follow ergonomics principle. So, we discussed this subject, we studied

this subject, so that, the performance and efficiency of overall system can be improved.

We can increase the productivity, at the same time we can reduce the error and accident.

Now, again we are coming to the definition of ergonomics. So, what is ergonomics or human

factors? Ergonomics is discipline or subject or science, as where we discuss about the

interaction between human and work elements and all other factors, which affecting this

interaction, to improve system’s performance, productivity, efficiency and at the same time

reduction of error and accident. So, this is the overall definition of ergonomics by

or human factors.

. Now, if we move towards the history or origin

of the subject, that how this subject ergonomics or human factors developed. So, first the

word ergonomics, was used in 1857 by Jastrzebowski in the journal nature and industry. He mentioned

that one scientific approach, regarding the problems, that are imposed by work, is needed

and he suggested that there is requirement to create a separate science, which will deal

with these issues, like in order to obtain from this science, the best with the least

effort, with the high satisfaction, for the own and public welfare and by acting fair,

with regard to own conscience and others. So, long back 1857 the word ergonomics was

coined. Now, in 1949, Murrell in England reinvented the coined word ergonomics.

So, that is in 1949, after that in 20th century, mid of the 20th century, then not only ergonomics,

other words also came like human engineering in German speaking areas. Anglo-American language,

they mention this science for this subject as human factors and in European countries

they called it ergonomics. So, the human engineering or ergonomics, which was first coined in 1857

gradually in different countries or different parts of the world, took different names;

like human engineering, human factors or ergonomics. Not only these names, there are so many other

precursors of ergonomics; like time study, motion study, these are also other precursors

which has been used by various authors.

Now, most widely used or widely accepted definition of ergonomics is given by international IEA,

international ergonomic association. International ergonomic association, as per their definition

what is ergonomics. They define ergonomics is a scientific discipline, concerned with

the understanding of the interactions among humans and other relevance of a system, and

the profession. So, this is the ergonomics as a subject, and here ergonomics as the profession

and the profession that applies theoretical principles, data, methods, to design, in order

to design, in order to optimize human well-being and overall system performance. So, earlier

defined ergonomics as a subject, as well as, as a profession, now who are ergonomists?

As further definition of IEA, practitioners of ergonomics, an ergonomist contribute to

the design and evaluation of tasks, jobs, products, environments and systems, in order

to make them compatible with the needs, abilities and limitation of the people. .

. So, IEA define both; what is ergonomics, as

well as who are ergonomist. Then down the line, years after years in various research

papers, various researchers, research papers for or books, they have mentioned ergonomics;

defined ergonomics as per their understanding. If you see this definition, by Fernandez (1995),

the design of the workplace, equipment, machine, tool, product, environment and system taking

into consideration that human physical, physiological, biomechanical and psychological capabilities

and optimizing the effectiveness and productivity of the work system, while assuring the safety,

health and well-being of the workers. In general, the aim in ergonomics is to fit the task to

the man, not individual to the task, as we have already mentioned. So, in this way, if

you go through all these definition, so various authors in their research paper, they have

defined differently.

. Now, in the research paper, Jaffar et al.

(2011) they mentioned the commonly highlighted view of the definition of ergonomics, is mainly

about the relationship between human, machines, systems, job design and the work environment.

Now, in 1959, we are discussing about the history. So, after history, we have discussed

few definitions of ergonomics, and then if you look at this one in 1959 various scientific

organizations dealt with ergonomics grouped under the roof of international ergonomics

association. So, in 1959, ergonomics, international ergonomics association was originated, then

in India we are talking about Indian ergonomics, Indian society of ergonomics, because we are

from India, Indian Institute of Technology, Guwahati. So, in this curriculum, in this

course we emphasize little bit about the ergonomics scenario in India. So, for that purpose, here

I have mentioned the Indian society of ergonomics. The Indian society of ergonomics was established

in 1983 and it is the only professional body in India, which is dealing with ergonomics

and human factor professionals in India.

. Now, so far during discussion of definition

of ergonomics and human factors, we have many times used that word; sometimes you are giving

ergonomics, sometimes you are mentioning as human factors, but now the question is coming,

are these two words human factors and ergonomics, are they synonymous, or these two are completely

different words or what is the relation between ergonomic human factors and ergonomics. So,

if we look at the development of both these subject area, then well find that the subject

area human factors, actually developed in United States of America (USA) and its root

subjects are, roots are grounded in psychology, applied/experimental psychology, engineering

psychology and human engineering. So, the subject human factor, human factors or human

factor engineering, actually developed from some other discipline like psychology and

it was mainly popular in USA. On the other hand, if we look at the ergonomics,

ergonomics is popular in European countries, and the subjects from which this subject evolved

or flourished, those subjects are actually anatomy, physiology, industrial medicine,

design and architecture. So, from all these subjects, that ergonomics to input and gradually

established as a new branch; that is ergonomics. As such, there is no difference between human

factors and ergonomics. These two words, human factors and ergonomics, now a days are being

used synonymously, means their meanings are same. Only difference is the, from which subject

it is originated, at the same time where it is much more popular, in which countries,

only there is the difference. But in other words these two, human factors and ergonomics,

these two words are synonymous. For that reason, if you look at this portion, in USA, human,

which was earlier known as human factors society, has recently changed its name to human factors

and ergonomics society. To emphasize that human factors and ergonomics are not different,

this is synonymous only.

. Now, while we are discussing about ergonomics,

then we are moving towards system design approach in ergonomics. So, already during discussion

of definition of ergonomics to we mentioned, that human, work element and surrounding physical

environment, these three components comprises a system. So, in this example, Bishe in 2012

in his book, he mentioned, the human as a systems component, designers must treat the

human to the component or integral component of the system, that has been designed. The

process for designing the vehicle, should, does involve the consideration of the following

major components; one is; obviously, driver, then vehicle and environment, because he is

defining the system approach of ergonomics in the field of automotive ergonomics. In

automotive ergonomics, while there is interaction between driver and vehicle, in that interaction

there is surrounding environment in driver-vehicle interaction.

With this driver-vehicle interaction, he has described various system components. Now,

if you look at the driver and user. Driver and user, while we are discussing about driver

and user, we must know about the characteristics, capabilities and limitation of driver. Similarly,

for vehicle we need to study type, size, body shape, subsystem components, all these. Similarly,

while you are talking about environment, then road condition, traffic, weather, dust, illumination

level or it is daytime or night. So, all these factors are related to environmental variables.

Now this overall system, driver is interacting with the vehicle, where there is are these

environmental factors. In this interaction, why the study of this interaction is important?

Because we need to discuss about performance, how will, how much task completion time, errors.

So, we need to discuss about the performance, We need to discuss about the preference; like,

dislike. Similarly, perception, quality, craftsmanship

workmanship, harmony. So, in driver- vehicle interaction also, that system, driver vehicle

interaction, in that case the system is comprising of these three factors and this interaction

is going on and there is major role of ergonomics, because that vehicle; its operation, its design,

everything is actually performed by human being only. So, key learning from this slide

is that, if any system, while we are designing that vehicle, we should not feel that, driver

is out of that system, the whole vehicle design process, we include both driver or human or

passenger, and at the same time it, we should also consider the surrounding environment.

. Now, in this slide we have categorized those

three components; what we are discussing so far, that in this system, man-machine-environment

system, there are three components. One is human component, second is machine component

and the third one is environmental component.

. So, under human component what we are discussing.

We are discussing about dimensional requirement, physiological requirement, biomechanical requirement

and psychological requirement. So, these are discussed under human component. Similarly,

under machine component what we discussed. We discussed about physical attributes of

that machine or facility or the product, then energy to run that machine, then safety and

hygiene, force requirement, moving parts all these are actually coming under machine component.

Similarly, under environmental component what we are discussing; the thermal condition,

visual, illumination, glare, then auditory, vibration, radiation, dust. So, all these

characters are discussed under environmental component.

Now, for any system there are three elements, three basic components; one is the input,

process and output. In man-machine system also, these three factors will be available;

one is the input, second is process, third one is output. Now if you look at this diagram;

in this side, man/ human or user or operator. Human user operator, for that there are three;

first input, process, output. Similarly, this side is the machine part, machine part for

machine also there is, output, process, input. Now if I give the example it will be much

easier to understand. If we give the example; say I am human being. So, we should know about

the characteristics of the human, user characteristics, user capabilities, user limitations. Now if

we take the example of my interaction with the laptop, then what is happening. As a human

being, I am typing on the, first input. First, we are receiving the input. We are receiving

the input from the computer screen, I am looking at the computer screen, input is coming through

my visual sensory system and that information is going to my brain. First information, I

am pursuing that information, through my visual sense, special sense, then it is going to

my next, it is going to my brain, it is being processing.

So, first input is received by various sensory channels. In this case, particularly in this

case I am receiving information through my eyes and then it is going to my brain. In

the brain it is being processed. After that, some output is there. What is that output?

After processing in the brain then I am pressing the key. So, that is actually neo-muscular

action. So, first I am receiving the information from the computer. I am processing that information

in my mind, in my brain, and then I am doing some muscular activity, you know muscular

activity; that is the output, whatever is the output from my side; that is actually

going as the input for the computer. So, my output that is typing of that key is going

as an input for the computer or laptop. While I am pressing any key that is actually

input for the machine, then machine processing that one, that laptop is processing that one,

mechanical; either mechanical process is there, or electronic process is there. Then machine

is giving some output, the screen is now changed. So, this step after pressing the key, that

input is going, it is processed electronically in that laptop and ultimately it is giving

some output, it is moving towards the next thing.

Then whatever is that output is provided by the machine in this example, laptop. So, whatever

output is provided by the laptop, that again going as the input for human being. So, while

I am pressing, it is going to the next screen and now I am looking at the next screen. So,

this is the input for me and this interaction man and machine, this interaction is going

on, and this interaction is also influenced by surrounding immediate environment as well

as the overall so many other factors; like organizational factor psycho-social factors,

so many other factors also affect this interaction. So, regarding the system design approach,

it is very important. in the earlier slide also we mentioned, in this slide that human

is the prime system component because whatever we are designing, whatever we are developing

that is for human, for the people, that is developed by the people and for the people,

as the design process considering these three factors, three things, so this is very important.

Now, while we are discussing about ergonomics, there are. You will find one word, that is

ergonomic stressors. What are ergonomic stressors? Any condition that poses biomechanical stress

or on human body leading to an increased risk of developing musculo-skeletal problem; that

is known as ergonomic stressesors. There are varieties of ergonomics stressors; like excessive

force exertion, awkward working posture, repetitive motion, heavy load handling insufficient recovery

time, movement of body joints beyond the comfort range, prolonged duration of work, psycho-social

factors, adverse physical condition; like vibration, heat, cold, noise, illumination,

then sustained posture, means we are unable to change the posture; we are undergoing a

constant posture. So, all these factors these are only a few of the stressors. There is

a very lengthy list; all these factors actually affect the human body, human performance and

ultimately productivity.

. Now, after discussing the definition of ergonomics,

various system approach in ergonomics, here we are moving towards importance of ergonomics,

why knowledge of ergonomics is important for designing any product or facility. Because

ergonomics is such a subject, it actually deals with occupational health. It deals with

efficiency, productivity of the system and also it is deals with the various safety issues.

If any product, facility or process design, if we follow ergonomic principle, then what

will? If you do not follow them what will happen. Then there will be fatigue, pain,

illness, low morale, frustration, irritation, all these things will happen. And ultimately

in the long run, it will lead to poor quality, absenteeism, higher cost, higher employee

turnover, requirement of training; this will be the output.

On the other hand, if we can use ergonomic principle in our day to day life, where we

are developing some product, facility, then we will get so many benefits, what are those

benefits. There will be higher productivity, higher quality, reduced operator injury, increased

morale, greater job satisfaction, low medical and insurance costs and reduced time and so

on. So, from this it is very clear, ergonomics is a subject, which is dealing with these

types of important areas; like occupational health, safety, productivity, efficiency.

And if we follow ergonomics then we will have so many benefits. So, knowledge of ergonomics

is very much important, while we are designing or developing some product, facility or process.

So, if we recall that slide, which is mentioned that we start from design, first. First, we

have some basic idea about the design, then will discuss about basics of ergonomics, its

definition. So, now, the point is that, what is the relation between these ergonomics and

design, if you see this statement, Chowdhury et al. (2012), they rightly pointed out that

design and ergonomics are actually complimentary to each other, like a lock and key model,

without key, lock is useless. On the other hand, without lock, key is valueless. So,

relationship between this design and ergonomics, actually they are complimentary to each other,

ergonomics or human factors engineering is a multidisciplinary science, which deals with

designing equipments or devices and work places that fit to human body, its movement and cognitive

abilities in relation to their work performance. Whereas, design is a scientific branch or

a particular product or facility or output is made following specific methods from predefined

ideas. So, ergonomics is actually used in the design

process. Again we can recall that slide. In that slide we mentioned that, in the design

development phases, we have to consider, we have to provide ergonomic inputs from the

very beginning .Very beginning means from conceptual phase, then; obviously, in design

phase and detailed design phase also. Dul et al. (2012) mentioned that design becomes

successful, only by incorporation of ergonomics features within it. So, for ergonomist or

human factors engineers, engineering is actually a design driven discipline. So, what is ergonomics?

So, he clearly pointed out that ergonomics or human factors engineering is actually a

design driven discipline, where we have to put knowledge of ergonomics, so that we can

make our design better.

As we have already mentioned, design becomes successful, only when we are incorporating

ergonomic knowledge in the design process. So, what is successful design, what is good

design? The successful design or good design is that, where in the design we have considered

ergonomic principle or we have provided ergonomic consideration into that product, whatever

product we are developing or whatever facet we are developing, we have to think, that

is, human compatibility of that product. Now, here it is one example.

In this example, this is an existing thresher. Thresher is one equipment that is generally

used for threshing various types of grains. So, that thresher, if we want to redesign,

how we proceed. We in various steps, we follow, we will provide various ergonomic input and

gradually to develop this type of redesigned product where we made some CAD model of that

product, again go for the actual prototype and then refinement of that prototype.

Now, ergonomically designed, is some time, is used misnomer now a days. . This is very

true, because many places, or on many advertisements you will find, it is written ergonomically

designed, that may be for furniture, that may be for utensils, that may be for so many,

wide range of products, people are mentioning widely that ergonomically designed, but what

is ergonomically designed, if you look at those advertisements we will find nothing

is there. Those products, in many cases, those products are really not ergonomically designed

and there are so many design loop holes or false. For example, this type of advertisement

you will find, that this tool is ergonomically designed, but truly speaking this is not.

If you study this one, then you will understand that is not ergonomically designed, that is

not good for sitting also. Similarly, ergonomically designed handle;

here you can clearly understand that there is no coating, no cover. So, whenever you

will hold this, if this pan is hot; obviously, you can a not hold the handle. Similarly,

this type of spoon, that manufacturer or the seller claim that this is an ergonomically

designed, but if you check the usability, sorry. So, if you check the usability that

is actually not good for use, but it does not mean that all the products in the market

are not ergonomically designed or a good design; obviously, there are so many products in the

market which are really good and various ergonomics or human factor aspects has been considered

in their design. So, one example is this one, finger loop bypass pruner. So, this is really

ergonomically designed. We have considered human hand dimension, gripping and so many

other issues.

. So far, what we have discussed. We discussed

about design, then gradually moved to ergonomics, next we discussed what is the relation between

ergonomics and design then we are coming to physical ergonomics versus virtual ergonomics.

Now what is physical ergonomics and what is virtual ergonomics. In physical ergonomics,

if you look at these two images. So, in this case, real human being is operating this grass-cutter

machine and this is the CAD generated human model operating, the CAD model of the grass-cutter

machine. In both the cases, so what is happening, human-machine interaction is going on, but

this interaction is going on in real scenario, means in physical environment. That human

being is real, product is also real and interaction is going on and that interaction is going

on in real life. So, while we are studying this human-machine compatibility in physical

mode that is called physical ergonomics. On the other hand, while the CAD generated

environment, as human modeling is CAD generated, product model is also CAD generated, while

we are studying the compatibility between products and human, that is coming under virtual

ergonomics. So, broadly we can categorize ergonomics, in these two areas; one is physical

ergonomics, another is virtual ergonomics. In digital human modeling software, we go

for this virtual man-machine interface and virtual ergonomics evaluation.

Now, what are the challenges to ergonomist, why ergonomics is important, and how we can

use this type of CAD software generated human model and use that human model for various

ergonomics evaluation or providing ergonomic input in the design. So, here you can see,

there are huge variations in human body, shape and sizes in population. Similarly, in the

market also, there may be different types of product in the market; otherwise in your

mind there are thousands of concepts of the new product. Now how will you understand,

that which product will be optimally fitted with the human requirement. Human requirement

in terms their body dimension, their capability, mean all those points, capabilities, limitations

and all these.

Next, the same thing we can evaluate, which product is good or for the population, for

the wide range of population. So, for that purpose we can go for this type of physical

ergonomic evaluation, where the product model or the product we can acquire and we can go

for real human …….[Not audible]. We can ask different types of real human, who are

real human in different types, in terms of say; age variation, sex variation, somatotype

variation? So, we can ask fat person, thin person, children, adult, different types of

people we can call, we can ask them to use the product and get the feedback.

On the other hand, what we can do, but if we go for this type of process, then this

is time consuming. Then if we find any problem in that design, again we have to go for redesign

and modification, that will be costly, because already you have made that product. So, redesign,

modification will be time consuming, costly, then there will be wastage of material, so

many problems are there, but the same evaluation, if we do in virtual environment like this

way, if we generate CAD model of the, CAD model for human and we can vary, we can make

male model, female model or you we can prepare the human model as per somatotype variation,

age variation.

Similarly, we can make the CAD model of the product. After developing CAD model of human

and CAD model of the product, what we can do, we can go for interfacing these two, with

that appropriate working posture. We can simulate various activities and that time we can check,

various, that whether this is compatible with the human body dimension, dimensional requirement

or anthropometric that is anthropometric requirement, or biomechanical requirement and whether that

human can operate this equipment or machine comfortably or not, In this way, using virtual

environment, in virtual environment, that CAD generated environment, using digital human

model, using CAD product model, we can evaluate, we can go for various types of ergonomic evaluation.

Fine, so far we have discussed about design, it should be in ergonomics, relationship between

ergonomics and design, then what is virtual ergonomics, what is physical ergonomics, and

what is virtual ergonomics. Now as I mentioned I am assistant professor from Indian Institute

of Technology. So, for Indian students, we want to give some information about how ergonomics

originated and developed in India.

So, for that purpose in the next few slides we will discuss about ergonomics in India.

In this developing country, India, ergonomics actually started long back

in 1945. Industrial health center and advisory committee by Indian research and research

fund association I ICMR was established. Then, in 1955 ergonomics research started in department

of physiology, Presidency College, Calcutta. In 1960, Industrial physiology division, Central

Labour Institute, Mumbai and Work physiology division, Central mining research institute,

Dhanbad and they started research in the field of occupational health and ergonomics. Here

most important thing, these are only related to research, but in 1971, first postgraduate

course in ergonomics and work physiology was introduced in Calcutta University, by this

person. He is Professor R.N.Sen, the first academic course of ergonomics and work physiology

was initiated in 1971 at University of Calcutta by this pioneer ergonomist professor R N Sen.

Then years after years, in so many colleges, universities they introduced course, full-fledged

course on ergonomics or as a part of their curriculum they started. Presently in India

there are various academic institutions, where ergonomics is being taught. So, this is a

list of those colleges or universities, for example, Calcutta University, Vidyasagar University,

Burdwan University, Kalyani University. So, there is a, many of the IITs also, then IISC

Bangalore, NITs. So, in many institutions of India right now, these academic institutions

are running course related to ergonomics. And on the right side panel, we will find

various research papers, where say overview of ergonomics, ergonomics meets and a research

in India. So, that has been published in these journals.

So, you can go through this thing, then, will get more ideas or more knowledge about the

development of ergonomics in India. Growth of ergonomics in India by K K Ganguly in 2009,

he has published. Similarly, he has another publication in 2013, ergonomics for Indian

industry. So, if we go through these literatures, then we will get a fair idea about history

and development of ergonomics in Indian scenario, then there are many other academic institutions,

where these course, ergonomics or human factors related course are been taught.

So, here I have listed almost 30 institutions, similarly in many other institutions,where

they are not teaching that course with the name of ergonomics or human factors. In their

curriculum they have mentioned, the similar topics under occupational health and safety.

So, these are the institutions where occupational health and safety related forces courses are

being taught in India. So, here is also a lengthy list, you can go through one after

another. So, here I have listed almost 24 institutions.

Then, there are many research institutes which are dealing with research, R & D, other R

& D labs on ergonomics, as well as occupational health. So,out of those research institutions,

these are the popular one; Defence Institute of Physiology and Allied Sciences, DRDO, Delhi,

National Institute of Occupational Health, NIOH emdabad, Central Labour Institute, Mumbai,

Regional Occupational Health Center, Kolkata, then National Institute of Rehabilitation

Training and Research, Orissa, National Institute of Orthopedically Handicapped, it is also

in Calcutta.

So, now there is some information related to my lab, where I am associated. This is

ergonomics laboratory and at department of design, IIT Guwahati. So, in our lab we have

the state of art facility for different types of ergonomic evaluation. So, I suggest all

the students to explore this website, then, you will get much more idea about various

types of facilities and our publications and also what types of research is going on in

Indian scenario in the field of ergonomics.

Now, domain of specialization, already we have mentioned that ergonomics, we can categorize

physical ergonomics and virtual ergonomics, in terms of whether that ergonomic evaluation

is going on, in physical environment or in virtual environment, but as a subject, ergonomics,

which is being categorized in the three different domains. What are those domains; one is physical

ergonomics, another is cognitive ergonomics, another is organizational ergonomics. So,

these three are the domains or specialization under ergonomics. In physical ergonomics,

we study these areas; human anatomy, anthropometry, physiology, biomechanics.

In cognitive, mental processes, perception, reasoning, motor response. Similarly, in organizational

ergonomics, we discuss about organizational structure, policies, processes. Now, here

are three examples, of different types of, different domains. So, one is this one, physical

ergonomics. So, what is in this, what it is shown? It is shown, whether human body dimension

is compatible with the dimension of the physical dimension of the product. So, that type of

compatibility study, in physical environment where we are discussing about the anthropometric

compatibility or posture or comfort; that it is coming under physical ergonomics.

Similarly, under cognitive ergonomics, say for example, decision making. In in front

of you, there are so many products and you have to select one particular product, you

have to make decision that which product you like. So, that visual information processing

or auditory information processing or decision making. So, all these areas actually coming

under cognitive ergonomics. Similarly, if you look at this, this is an example of a

class room, in this class room example, it is coming under organizational ergonomics,

mean that organization, that is colleges or university, college and university administration

they have decided, that how should be the size of the classroom, what should be the

student-teacher ratio, how should be the space layout, all these things actually decided

by the organization. So, this is coming under organizational ergonomics. Now, if you go

through these three domains. So, physical ergonomics, it is concerned with human anatomical,

anthropometric, physiological and biomechanical characteristics,

as they relate to the physical activity. Relevant topics include working postures, material

handling, repetitive movement, musculo-skeletal disorders, workplace, and so on. Similarly,

in cognitive ergonomics, is concerned with mental a processes; that is perception, memory,

reasoning and motor response. As they affect interaction among humans and other elements

of a system. Relevant topics include mental workload, decision making as we have already

mentioned in the earlier slide. Like this one physical. In the next one; this is physical

ergonomics, then cognitive ergonomics, the next one is organizational ergonomics.

In organizational ergonomics, it is concerned with optimization of the socio-technical system,

including their organizational structure, policies, and processes. Relevant topics include

communication, crew resource management, work design, design of working times, teamwork,

participatory design, community ergonomics and cooperative work. So, these areas are

coming under organizational ergonomics. So, now, these three domains will be much more

clear. So, we are giving in a. So, earlier slide we have discussed with a three different

example. One example for physical, one for cognitive and another for organizational.

But if we combine these three domains, in a single example, and how it is coming, we

are giving. Let us take the example of this class room. In this class room, in the same

actually these three domains are not separate; these are integral part of any system. These

are the integral part of any discussion, while we are discussing about physical ergonomics;

obviously, there is cognitive ergonomics and organizational ergonomics. See if we take

this example, class room. So, while teacher is interacting with the students, or the students

and the teacher is interacting with the overall workplace, then different domain of ergonomics

is involved, physical ergonomics. So, where this projection screen is placed, so that

all the students as well as the faculty members can see it clearly.

So, positioning of the screen is very important, that positioning of that screen, projector

screen, is coming under physical ergonomics, so that the students as well as teacher can

visualize it very clearly without much effort and without much neck movement. Similarly,

cognitive ergonomics; teacher is telling something, students are listening. Then on the projection

there is some visual information, students are perceiving those information through their

sensory modalities, particularly through vision sense and then they are replying to teacher.

So, this is coming under cognitive ergonomics. Similarly, the third part is, sorry, this

is mistake, this should be organizational ergonomics. In organizational ergonomics what

is there, in organizational ergonomics. So, providing audio visual facilities, by

the institute, in this classroom whatever audio visual facilities has been provided,

or whatever is the arrangement of the classroom, space layout, all these actually provided

by the institute. So, institute as an organization, decide that what, which type of audio visual

facility to be provided or what type of the classroom layout is required or what type

of furniture we purchased for that classroom. So, all these actually decided by the organization

as a whole. So, in every system, all these three domains of ergonomics can be discussed.

So, we have discussed this one with the example of this classroom, in the same classroom example,

we can discuss about physical ergonomics, cognitive ergonomics, as well as organizational

ergonomics.

Next, moving to human factors to be considered for design technology application, various

human factors or ergonomics issues, which we need to discuss in human-machine interaction.

Now here if you look at this chart, on y-axis it is user or operator characteristics. So,

these are the user or operator’s characteristics. On x-axis, it is machine or product characteristics,

so human characteristics and this is product or facility characteristics. Now how these

two characteristics are interacting with each other. Static physical requirement from user

side; users' physical requirement at the same time, static physical dimension of the product

or facility, that is discussed under anthropometry, so what is anthropometry. So, here you can

look at this color coding, these are characteristics of the user, these are the characteristics

of the product, and if you look at the color coding. So, what it indicates. It indicates

that anthropometry is a subject, where we discuss about static physical requirement

by the user or human and static physical dimension of the product.

While human is interacting with a product, human’s physical dimension whether human’s

physical dimension, is compatible with the product’s physical dimensions; that is coming

under anthropometry. Similarly, under biomechanics what we are discussing. We are discussing

dynamic physical requirement of the human body, with dynamic physical dimension; that

is coming under biomechanics. For example, one example, we can give, the reachability,

how human can move their different body parts, mainly particularly hand or leg, for reaching

or holding some object. And physical dynamic, physical dimension, say if someone opening

a door or closing a door. So, for that purpose how much human hand can move, at the same

time what that further facility for door movement, what allowances has been provided.

Similarly, if we look at this top one; aesthetic evaluation. Under aesthetic evaluation, what

we do, effective needs of human, at the same time ours or visual aesthetics of the product.

So, that is actually coming under aesthetic evaluation. Similarly, cognitive ability of

human being and operatibility of the product and machine, it is coming under information

processing. So, under information processing we discuss about what is the operational requirement

of the machine or instrument, at the same time whether that is compatible with the human-cognitive

ability, we will discuss about that. So, with this schematic diagram, it is very clearly

understood that various subject or discipline under the field of ergonomics, is actually

interaction between various characteristics of the operator and various characteristics

of the machine or product.

Now, in this subject ergonomics or human factors, we discussed various aspects of human or environment.

Physiological aspect, under physiological aspect, we discussed about cardio-vascular

response, respiratory response, metabolic response and ultimately all these response

leads to, if the product or facility, is not ergonomically designed. So, what it will do.

It will lead to physiological load or physiological stress, and when there is physiological load

or physiological stress, it ultimately affects human body systems. There are various systems;

nervous system, digestive system. So, all these systems actually will be affected by

physiological stress and human will become thin or he or she feels discomfort.

Similarly, under anthropometry and biomechanical aspect, various issues like anthropometric

compatibility, comfort of body joint parts, then weight and center gravity. So, these

factors we will study and while there is anthropometric or biomechanical incompatibility, then what

will happen. It will lead to musculo-skeletal load. There will be enhanced musculoskeletal

load. While there is musculo-skeletal, enhanced musculoskeletal load, it will in the long

run, it will develop different types of musculo-skeletal disorders. .

Now, various psychological aspects, in various psychological aspects we discuss about design,

color, texture, material of the product, concise information, universal appeal and aesthetics.

So, this psychological aspect ultimately relates to cognitive load. So, whatever information,

is been provided, by the instrument or human being is perceiving from that instrument or

product, that ultimately, increasing the cognitive work load of the human. If cognitive work

load is high, what is cognitive work load? Cognitive work load is the human perception

about the work being performed. If he feels that work is difficult, if he feels that work

is taking much mental effort or physical effort, then his cognitive work load is more.

If cognitive work load is high, then it will affect information processing, it will tell,

there will be sleep disorder , it will also affect physical health. Then under ergonomics,

we also discussed about various environmental aspects. We mentioned already that, level

of illumination, noise, vibration, radiation, all these factors we studied. Similarly, there

are also other aspects like socio-cultural aspects. Under socio-cultural aspect, we discussed

about motion-stereo type, handedness left-handed, right- -handed user’s educational status,

economic status, language and religions. So, many other issues actually

discussed under the field of ergonomics.

Now, moving towards the application, we already discussed why ergonomics is important, in

the field of design. Now, if we talk about applications where ergonomics is being applied.

Answer is ergonomics is applied everywhere, where there is human, there is application

of ergonomics and we have already defined that ergonomics is interaction between human

and his or her work elements. So, while human is interacting with any sort of product or

process or article or artifact, everywhere there is requirement of ergonomics. If In

any industrial or occupational sector, starting from aerospace engineering, agricultural sector,

fashion technology, health care, everywhere there is application of ergonomics. Even if

we say that, we want to design something for our pet, dog or cat. In that case also we

have to think, we are designing, for say one cage for that cat or dog. We are not designing

for them only; we are designing for human convenience. So, ultimately whatever you are

designing, that always have to keep in mind the human need, human requirement.

Now, this is only a very small list, in any field there is application of ergonomics.

So, here are, some examples are given; say for example, virtual environment, we are using,

we are going for ergonomic evaluation, in all the places references are provided. In

aerospace and aviation sector, there is also use of ergonomics, how we can design this

night vision goggles, then this type of helmet, then in various industrial sector how we can

use the knowledge of ergonomics, for betterment of their occupational health, for providing

their better infrastructure facility. So, that should, they can work easily, comfortably.

Similarly, not only this type of industrial sector or aviation sector, even in garment

industry, ergonomics is important, because we have to think that how that garment should

be designed. Not only it should be fitted with the human body, at the same time you

have to think that material of the garment or fabric type, fabric or material of the

garment. It should be such that, after wearing that garment; human should feel comfortable,

he or she should not sweat or it should not be feeling of too hot or it is too tight,

at the same time while someone is wearing some cloth, he or she must have the normal

range of motion of body parts. It should not restrict hand or leg movement or body parts

movement. So, that much allowances should be given in the design. Similarly, ergonomics

is used in different types of industrial product design, then automobile industry, automobile

sector, vehicle design, we use, we consider ergonomics, so that design can be improved.

So, now key learning from module one, so far what we have learnt. So, first we discussed

about definition of design and ergonomics. What is design, what is ergonomics, then stages

of product, workstation design. So, what are the key definitions we have, we mentioned,

that pre-conceptual phase, conceptual phase, pre-design stage, detailed design stage. So,

various stages in the design process, then relationship between design and ergonomics,

then whether ergonomics and human factors, these two words are different or they are

same, means synonymous. Then system design approach in ergonomics, we have discussed

about that, then when knowledge of ergonomics is required in field of industrial design

or engineering. System design approach in ergonomics already we have mentioned, then

another is ergonomics in India, how the subject ergonomics has been introduced in India and

how it is developing or it is flourishing, that is we also discussed.

We discussed about various academic institutions, research institutions, where this type of

ergonomics or occupational health and safety related courses are being taught. Then we

discussed about domain or specialization of ergonomics. We talked about physical ergonomics,

cognitive ergonomics and organizational ergonomics. Then at the end we discussed application of

ergonomics in various occupational or industrial sectors and in this slide we mentioned, particularly

that ergonomics is such a subject, its requirement is in everywhere, any facility, product or

any process, which is used by human, which is for the human or by the human or of the

human. There is obviously, requirement of ergonomics.

Now, you can note down these. All these information, that there are various useful online resources,

you can go through all these resources to get so many other information which has not

been covered within these slides. So, all these resources are very important. I suggest

all of you to explore those links.

And these are the references, which I have used in various slides for preparing the slides.

And at the end thank you all and this is a beautiful campus of our institute; that is

Indian Institute of Technology, Guwahati. I welcome you all to this beautiful campus.

Thank you.