Industrial Engineering and Management
Introduction to Human Factors
What is Human Factors
Human factors are illustrated by breakdowns in the
interactions between humans and the systems with which
they work.
We may define the goal of human factors as making the
human interaction with systems one that:
Reduces error
Increases productivity
Enhances safety
Enhances comfort
What is Human Factors
Naturally there are many more times when systems work
well. However it is characteristic of human nature that we
notice when things go wrong more easily than when things
go right.
It is the situation when things go wrong that triggers the
call for diagnosis and solution, and these are the key
contributions of human factors to system design.
What is Human Factors
Human factors involves the study of factors and
development of tools that facilitate the achievement of the
goals of human factors
Example:
Why did the worker suffer the back injury?
What is the amount of the load or the awkward
position required to lift it?
What is Human Factors
It is necessary to diagnose or identify the problems and
deficiencies in the existing human-system interaction
To do this effectively ,core knowledge of the nature of the
physical body (its size, shape, and strength) and of the
mind (its information-processing characteristics and
limitations) must be coupled with a good understanding of
the physical or information systems involved, and the
appropriate analysis tools must be applied to clearly
identify the cause of breakdowns
What is Human Factors
Having identified the problem, five different approaches
may be directed toward implementing a solution:
1. Equipment design
2. Task design
3. Environmental design
4. Training
5. Selection
What is Human Factors
Equipment design changes the nature of the physical
equipment with which humans must works
Task design focuses more on changing what operators do,
rater than the devices they use.
Sometimes task design may involve assigning part or
all the tasks to other workers or to automated
components
What is Human Factors
Environmental design implements changes in the physical
environment within which the task is carried out, such as:
improved lighting,
temperature control, and
reduce noise
A broader view of the environment could also include the
organizational climate within which the work is carried out
What is Human Factors
Training focuses on better preparing the worker for the
conditions that he or she will encounter in the job
environment by teaching and practicing the necessary
physical or mental skill
Selection is a technique that recognizes the individual
differences across humans in almost every physical and
mental dimension that is relevant for good system
performance
Design and Evaluation Methods
The goals of human factors specialists are generally to
make task:
easier,
more effective,
more satisfying to perform, and
safer
This is done by applying human factors principles,
methods, and data to the design of new products or
systems
Design and Evaluation Methods
The concept of design can be broad, including activities such
as the following:
Design or help design products or systems, especially
their interface
Modify the design of existing products to address human
factors problems
Develop training programs and other performance support
materials such as checklists or instruction manuals
Design and Evaluation Methods
Design ergonomically sound environments, such as:
individual workstations,
large environments with complex work modules and
traffic patterns,
home environment for the handicapped,
gravity-free environments, and so forth
Design and Evaluation Methods
Develop methods for training and appraising work groups
and teams
Apply ergonomic principles to organizational development
and restructuring
Perform safety-related activities, such as,
conduct hazard analyses,
implement industrial safety programs,
design warning labels, and
give safety-related instructions
Design and Evaluation Methods
Even when designers attempt to consider human factors,
they often complete the product design first and only then
hand off the blueprint or prototype to a human factors
expert
This expert have to comeback with criticisms of a design
that the design team has spent months and thousands of
dollars to develop
Cost/Benefit Analysis
The cost / benefit analysis is used to show management
that human factors should be included as part of the
design effort even if it does entail an extra expense,
because in the long run, it will save the company
money
In most instances, estimating the costs for human factors
effort is relatively easy because the designer tends to be
familiar with the costs for personnel and materials.
Cost/Benefit Analysis
Estimating the benefits tends to be more difficult and must
be based on assumptions
Some types of benefits are more common for one type of
manufacturer or customer then another
The total benefit of the effort is determined by first
estimating values for the relevant variables without human
factors intervention. The same variables are estimated
assuming human factor analysis. The benefit is the cost
savings between the two
Cost/Benefit Analysis
The following benefits that might be applicable
Mayhew(1992), and that can be estimated quantitatively:
1. Increased sales
2. Decreased cost of providing training
3. Decreased customer support costs
4. Decreased development costs
5. Decreased maintenance costs
6. Increased user productivity
7. Decreased user errors
8. Improved quality of service
9. Decreased training time
10.Decreased user turnover
Cost/Benefit Analysis
Other quantifiable benefits are health or safety related
(Alexander, 1995), such as:
1. Decreased sick leave or time off
2. Decreased number of accidents or acute injuries
3. Decreased number of chronic injuries (such as
cumulative trauma disorders)
4. Decreased medical and rehabilitation expenses
5. Decreased number of citations or fines
6. Decreased number of lawsuits
7. Increased employee satisfaction (lower turnover)
