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330 13 Cartography and Navigation

All of this is in stark contrast with mainstream process models. The x-axis and
y-axis of a process model have no meaning, e.g., the layout of the WF-net shown
in Fig. 13.6 was generated automatically without assigning any semantics to the
positions of activities. Although modeling tools allow for using colors, the color
typically has no semantics. The different types of model elements (e.g., activities,
gateways, events, connectors, and places) typically have a default color. Moreover,
the size of a model element also has no semantics. Typically all elements of a par-
ticular type have the same size.
Because size, color, and layout are not employed when creating business process
maps, the result is less intuitive and less informative. However, ideas from cartogra-
phy can easily be incorporated in the construction of business process maps. Some
examples:
• The size of an activity can reflect its frequency or some other property indicating
its significance (e.g., costs or resource use).
• The color of an activity can reflect the mean service time of the activity. For
example, activities that take longer than average are colored red whereas short
running activities are colored green.
• The widthofanarc can reflect the importance of the corresponding causal de-
pendency.
• The coloring of arcs can be used to highlight bottlenecks.
• The positioning of activities can have a well-defined meaning. Similar to swim-
lanes the y-axis could reflect the role associated to an activity. Similar to a Gantt
chart, the x-axis could reflect some temporal aspect.
It is important to use these conventions in a consistent manner across different
maps.

13.1.5 Customization

The same geographic area is typically covered by many different maps. There are
different maps depending on the type of activity they intend to support, e.g., bicy-
cle maps, hiking maps, and road maps. Obviously, these maps use different scales.
However, there are more differences. For instance, a bicycle map shows bicycle
paths that are not shown on motorists’ map.
Figure 13.7 illustrates that multiple views can be created for the same reality
captured in an event log. In earlier chapters, we already showed that there is no such
thing as the process model describing a process. Depending on the questions, one
seeks to answer, a customized process model needs to be created. In Sect. 5.4.4,we
referred to this as taking a “2-D slice of a 3-D reality”. The same process can be
viewed from different angles and at different levels of granularity. For noisy event
logs, one may prefer to focus on just the main behavior or also include less frequent
behavior. For example, from an auditing point of view the low frequent behavior
may be most interesting.