On the Flexibility of Declarative Process Specifications

Declarative process specifications, such as Declare, provide a natural framework to capture flexible business processes. However, the specification may be more, or less flexible, depending on how much freedom it provides – for example, a specification that is so strict it allows only one exact behavior (i.e., trace) can be seen as inflexible. Surprisingly, little attention has been given to this key feature in declarative process specifications, and how to measure it. In this paper, we therefore close this gap by investigating how to measure the degree of flexibility of declarative process specifications. We show how techniques for measuring the density of infinite regular languages can be effectively employed to define a measure of flexibility for constraint-based process specifications, focusing in particular on Declare. Also, we show when our measure (which is a limit) is guaranteed to exist for Declare specifications, and present how to actually compute our measure using known techniques.