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200 Chapter 6

Task Analysis and Modeling
Task analysis studies what knowledge workers must do with respect to specifi c actions
to be taken and/or cognitive processes that must be called upon to achieve a particular
task (e.g., Preece et al. 1994 ). The most commonly used method is task decomposition,
which breaks down higher-level tasks into their subtasks and operations. The lower
levels may make use of task fl ow diagrams, decision fl owcharts, or even screen layouts
to better illustrate the step-by-step process that has to be undertaken in order to com-
plete a task successfully. A good task analysis should show the sequencing of activities
by ordering them from left to right. In order to break down a task, the question should
be asked, “ How is this task done? ” If a subtask is identifi ed at a lower level, it is pos-
sible to build up the structure by asking “ Why is this done? ”
The task decomposition can be carried out using the following stages:
1. Identify the task to be analyzed.
2. Break this down into between four and eight subtasks. These subtasks should be
specifi ed in terms of objectives and, between them, should cover the whole area of
interest.
3. Draw the subtasks as a layered diagram, ensuring that it is complete.
4. Decide upon the level of detail into which to decompose. Making a conscious deci-
sion at this stage will ensure that all the subtask decompositions are treated consis-
tently. It may be decided that the decomposition should continue until fl ows are more
easily represented as a task fl ow diagram.
5. Continue the decomposition process, ensuring that the decompositions and num-
bering are consistent. It is usually helpful to produce a written account as well as the
decomposition diagram.
6. Present the analysis to someone else who has not been involved in the decomposi-
tion but who knows the tasks well enough to check for consistency.

Task fl ow analysis can include details of interactions between the user and the
current system, or other individuals, and any problems related to them. Copies of
screens from the current system may also be taken to provide details of interactive
tasks. Task fl ows will not only show the specifi c details of current work processes but
may also highlight areas where task processes are poorly understood, are carried out
differently by different staff, or are inconsistent with the higher level task structure.
An example of a task analysis is shown in table 6.4 .
Such task analyses are an important fi rst step in the design of knowledge applica-
tion support systems. A popular form of these has been around long before the term
KM came into common usage. EPSSs were and continue to be widely used provide