Showing posts with label
HUMAN FACTORS AND INDUSTRIAL ENGINEERING.
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Showing posts with label
HUMAN FACTORS AND INDUSTRIAL ENGINEERING.
Show all posts
Basic
definitions related to occupational
health and safety
Some
basic and powerful definitions related to occupational health and
safety are the following:
Health
Related
to the protection of the bodies and minds of people from illness
resulting from the materials, processes or procedures used in the
workplace.
Safety
Related to the
protection of people from physical injury. The borderline between
health and safety is ill-defined and the two words are normally used
together to indicate concern for the physical and mental well-being
of the individual at the place of work.
Welfare
Related
to the provision of facilities to maintain the health and well-being
of individuals at the workplace. Welfare facilities include washing
and sanitation arrangements, the provision of drinking water,
heating, lighting, eating and rest rooms. First aid arrangements are
also considered as welfare facilities.
Occupational or
work-related ill-health
Is concerned with those
illnesses or physical and mental disorders that are either caused or
triggered by workplace activities. Such conditions may be induced by
the particular work activity of the individual or by activities of
others in the workplace. The time interval between exposure and the
onset of the illness may be short or long.
Environmental
protection
Related
to the arrangements to cover those activities in the workplace which
affect the environment and, possibly, the health and safety of
employees and others.
Accident
Defined
as any unplanned event that results in injury or ill health of
people, or damage or loss to property, plant, materials or the
environment or a loss of a business opportunity.
Near miss
Is any incident that
could have resulted in an accident.
Dangerous occurrence
It’s
a near miss which could have led to serious injury or loss of life.
Hazard and risk
A hazard is the
potential of a substance, activity or process to cause harm. Hazards
take many forms including, for example, chemicals, electricity and
working from a ladder.
A
risk is the likelihood of a substance, activity or process to cause
harm. A risk can be reduced and the hazard controlled by good
management.
The difference
between hazard and risk
It
is very important to distinguish between a hazard and a risk – the
two terms are often confused and activities such as construction work
are called high risk when they are high hazard. Although the hazard
will continue to be high, the risks will be reduced when controls are
implemented.
The residual risk
The level of risk
remaining when controls have been adopted is known as the residual
risk. There should only be high residual risk where there is poor
health and safety management and inadequate control measures.
Evolution of industrial engineering (Part III)
Gilbreth’s work continued in motions using motion pictures for studying tasks and workers. He developed micro motion study, a breakdown of work into fundamental elements called “therbligs” (baed on Gilbreth spelled backwards).
Taylor’s concept of work element was broad, and based on time study requirements like “get tool”. Whereas Gilbreth’s work was based on breaking down the elements further into basic individual therbligs, such as “reach for tool and pick up tool” instead of “get tool”.
There were many followers of Taylor and Gilbreth in the 1900s. They believed that Taylor’s work emphasized motion measurement whereas Gilbreth emphasized motion analysis. With time, it became clear that both approaches were necessary and were essentially interdependent. Ultimately what is important is the best of both of these efforts, namely, the right motions with the minimum of time. Thus evolved a term “Methods engineering” which is an important function of industrial engineering.
The concepts of time and motion studies developed by Taylor and Gilbreth are still the basis for industrial engineering. Even today, over fifty percent of industrial engineering activities are related to this concept.
Evolution of industrial engineering (Part I)
In any productive environment, whether it is an industrial plant, an institution such as a hospital, restaurant, office, etc. there is a need to improve the quality of work. This means that a given task should be carried out efficiently and accurately in terms of time and effort spent.
During the industrial revolution of the 18th and 19th century, many small ownership based businesses grew into larger enterprises in which a number of manual tasks were performed by mechanical and steam operated machines. At that time there weren’t adequate tools or working conditions and there was considerable exploitation of labor. As a result, there were wide variations in output from different workers and different factories making the same product.
Frederick Taylor, a mechanical engineer was who observed that better methods could be established even for a simple task as handling iron ore and coal for a blast in a steel plant. He pursued the task of establishing a norm for the weight and size of the shovel for scooping and transferring material. He observed and proved that instead of using the largest shovel to move the maximum material in a day, it was better to design a shovel which could be comfortably used by the workers on a repetitive basis without tiring or injuring them at the end of the day. When his plan was implemented, he reduced the manpower by over 25%. Taylor was also considered to be the father of scientific management because he was a pioneer in improving methods and establishing the incentive system for workers with the benefit of higher productivity to the owners and higher wages for the workers.
Methods design, motion and time study
What’s methods design
Methods design is the analysis of the various ways a task can be done so as to establish the one best way. It includes motion analysis (the study of the actions the operator can use and the advantages and/or disadvantages of each variation) and standardization of procedure (the selection and recording of the selected and authorized work methods).
While ‘‘time and motion study’’ is the more commonly used term, it is more correct to use ‘‘motion and time study,’’ as the motion study to establish the standard procedure must be done prior to the establishment of a standard time to perform that work.
Motion study definition
Motion study can be defined as “the analysis of the manual and the eye movements occurring in an operation or work cycle for the purpose of eliminating wasted movements and establishing a better sequence and coordination of movements.”
Time study definition
Time study can be defined as “the procedure by which the actual elapsed time for performing an operation or subdivisions or elements thereof is determined by the use of a suitable timing device and recorded. The procedure usually but not always includes the adjustment of the actual time as the result of performance rating to derive the time which should be required to perform the task by a workman working at a standard pace and following a standard method under standard conditions.”
Attempts have been made to separate the two functions and to assign each to a specialist. Although motion study deals with method and time study deals with time, the two are nearly inseparable in practical application work. The method determines the time required, and the time determines which of two or more methods is the best. It has, therefore, been found best to have both functions handled by the same individual.
The Hawthorne Experiment and the developing of Industrial Engineering
A major episode in the quest to understand behavioral aspects was the series of studies conducted at the Western Electric Hawthorne plant in Chicago between 1924 and 1932. These studies originally began with a simple question: How does workplace illumination affect worker productivity? Under sponsorship from the National Academy of Science, a team of researchers from the Massachusetts Institute of Technology (MIT) observed groups of coil-winding operators under different lighting levels. They observed that productivity relative to a control group went up as illumination increased, as had been expected. Then, in another experiment, they observed that productivity also increased when illumination decreased, even to the level of moonlight. Unable to explain the results, the original team abandoned the illumination studies and began other tests on the effect of rest periods, length of work week, incentive plans, free lunches, and supervisory styles on productivity. In most cases the trend was for higher than normal output by the groups under study.
Approaching the problem from the perspective of the “psychology of the total situation,” experts brought in to study the problem came to the conclusion that the results were primarily due to “a remarkable change in the mental attitude in the group.” Interpretations of the study were eventually reduced to the simple explanation that productivity increased as a result of the attention received by the workers under study. This was dubbed the Hawthorne effect. However, in subsequent writings this simple explanation was modified to include the argument that work is a group activity and that workers strive for a sense of belonging—not simple financial gain—in their jobs. By emphasizing the need for listening and counseling by managers to improve worker collaboration, the industrial psychology movement shifted the emphasis of management from technical efficiency—the focus of Taylorism—to a richer, more complex, human-relations orientation.
You can see more in “Industrial Engineering Handbook”
HUMAN FACTORS IN INDUSTRIAL AND SYSTEMS ENGINEERING
Human factors is a science that investigates human behavioural, cognitive, and physical abilities and limitations in order to understand how individual and teams will interact with products and systems.
Human factors engineering is the discipline that takes this knowledge and uses it to specify, design, and test systems to optimize safety, productivity, effectiveness, and satisfaction.
Human factors is important to industrial and systems engineering because of the prevalence of humans within industrial systems. It is humans who, for the most part, are called on to design, manufacture, operate, monitor, maintain, and repair industrial systems. In each of these cases, human factors should be uses to ensure that the design will meet system requirements in performance, productivity, quality, reliability, and safety.
The importance of including human factors in systems design cannot be overemphasized. There are countless examples that illustrate its importance for systems performance. Mackenzie found in 1994 that in a survey of 1100 computer-related fatalities between 1979 and 1992. 92% could be attributed to failures in the interaction between a human and computer. The extend of the 1979 accident at the Three Mile Island nuclear power plant was largely due to human factors challenges, almost resulting in a disastrous nuclear catastrophe. The infamous butterfly ballot problem in Florida in the 2000 U.S. presidential election is a clear example of an inadequate system interface yielding remarkably poor performance. Web sites such as baddesigns.com and thisisbrokenn.com provide extensive listings of designs from everyday life that suffer from poor consideration of human factors. Neophytes often refer to human factors as common sense. However, the prevalence of poor design suggests that human factors sense is not as common as one might think. The consequences of poor human factors design can be inadequate system performance, reduced product sales, significant product damage, and human injury.
