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The purpose of front-end analysis is to understand the users, their
needs, and the demands of the work situation. There are many
front-end analyses and they differ substantially in the time they
require. Hence, the analysis method needs to be matched to the
development timelines and priorities of a project. Not all activities
are carried out in detail for every project, but in general, the
designer will need to answer the following questions before design
solutions are created:

1. Who are the users? This includes not only users in the traditional
sense, but also the people who will install, maintain,
monitor, repair, and dispose of the system.

2. Why do users need the product and what are their preferences?

3. What are the environmental conditions under which the
system or product will be used?

4. What is the physical and organizational context of the users’
activity?

5. What major functionsmust be fulfilled by a person, team, or
machine?

6. Whenmust tasks occur, in what order, and how long do they
take?

Y “If you want to improve a
piece of software all you have
to do is watch people using it
and see when they grimace,
and then you can fix that.”
D. Kelley [38]

These questions are answered with various analyses that begin
by collecting data, often by observing and talking with people.
These data are then analyzed to support design decisions. We use
the term task analysis to describe this process, which can vary
substantially in its level of detail. In general, the more complex and
critical the system, such as air traffic control, the more detailed the
task analysis. It is not unusual to spend several months performing
this analysis for a complex product or system.

Although direct observation is the primary technique for collecting
information about tasks and activities, it is not always the
most effective. Accident prevention is a major goal of the human
factors profession, especially as humans are increasingly called
upon to operate large and complex systems. Although human
factors experts rarely observe accidents directly these critical incidents
can be analyzed to determine the underlying causes. In
Chapter 1 we discussed how Fitts and Jones interviewed pilots after
crashes and near crashes to identify opportunities to improve aircraft
design. Accident analysis has pointed to several cases where
poor system design has resulted in human error. As an example, in
1987 Air Florida Flight 90 crashed into the 14th Street Bridge on the
Potomac River shortly after taking off fromWashington National
Airport, killing 74 of the 79 passengers and crew. Careful analysis of
the events leading up to the crash identified training and decision
errors that led the pilots to take off even though snow and ice had accumulated on the wings. Accidents usually result from several
coinciding breakdowns, and so identifying human error is the first
and not the last step in understanding accidents.

The “Five Whys” help identify
the multiple causes of
accidents.

Practicing the “Five Whys” by tracing back the causes of an
event by asking “why” at least five times can be useful in going beyond
human error as the cause of an accident. For the Air Florida
Flight 90, this might mean asking why the aircraft had inadequate
lift? (ice accumulated on the wings). This leads to the question:
why did the aircraft take off with ice on its wings? (aircraft accumulated
ice as it waited in taxi line for 49 minutes before takeoff),
which then leads to the questions: why did the pilots decided not to
return for de-icing? (production pressure and lack of experience),
why did the pilots did not notice the severity of the icing problem as
they began taxied for takeoff? (captain failed to address concerns
of first officer). These series of questions typically show multiple
unsafe elements associated with training, procedures, controls and
displays, that should be considered before rather than after an accident.
This requires a proactive approach to system safety analysis
rather than a reactive one such as accident analysis or accident
reconstruction. This safety analysis is one particular example of
understanding users, their operating environment, and the tasks
they must performand is addressed in greater detail in Chapter 16,
where we discuss system safety.

In contrast to accident analysis, which typically focuses on systemsafety,
time-motion studies developed by Taylor (Chapter 1), focuses
on improving performance of manual work. Taylor’s detailed
observations dramatically improved steelworker productivity by
precisely recording the movements and timing of actions of workers
on assembly lines. These time-motion studies continue to be an
important technique to improve efficiency and avoid injury associated
with manualmaterials handling, which we discuss in more
detail in Chapter 13 (biomechanics). Human factors engineers can
incorporate knowledge gained in time-motion studies to understand
user needs, the context that the work is to be conducted, and
the sequences of tasks.

Time-motion studies identify
ways to improve worker
efficiency

Understanding users’ needs for computer systems and consumer
products often benefits from an approach termed contextual
inquiry [39]. Contextual inquiry provides an understanding
of users’ needs by going to users’ workplace or wherever the systemwould
be used, and adoptingmaster-apprentice relationship.
The interviewer acts as an apprentice learning from the master
regarding how to perform a particular activity. As an apprentice,
the interviewer asks the master to verify his or her understanding
by commenting on task descriptions and prototypes, as simple as
a series of sketches to show screens of a potential application.

Y Contextual inquiry reveals
user needs through careful
observation.

Understanding tasks is essential, whether the goal is to prevent
accidents, make assembly lines more efficient, or create delightful
products. This understanding goes beyond simply documenting
activity, but involves establishing a deep empathy for the user.
Without some formof front-end analysis, designers and engineers often find it hard to create systems that serve peoples’ needs effectively.
Depending on how the data are collected and analyzed,
the methods take on many names, but they all aimto understand
users, their environment, and the tasks they must perform. Here
we describe them under the general termof task analysis.