  Complex Event Processing (CEP) is one technique used to the handling data
flows. It allows pre-establishing conditions through rules and firing events
when certain patterns are found in the data flows. Because the rules for
defining such patterns are expressed with specific languages, users of these
technologies must understand the underlying expression syntax. To reduce the
complexity of writing CEP rules, some researchers are employing Domain Specific
Modeling Language (DSML) to provide modelling through visual tools. However,
existing approaches are ignoring some user design techniques that facilitate
usability. Thus, resulting tools eventually has become more complexes for
handling CEP than the conventional usage. Also, research on DSML tools
targeting CEP does not present any evaluation around usability. This article
proposes a DSML combined with visual notations techniques to create CEP rules
with a more intuitive development model adapted for the non-expert user needs.
The resulting tool was evaluated by non-expert users that were capable of
easily creating CEP rules without prior knowledge of the underlying expression
language.
