The many meanings of UML 2 Sequence Diagrams: a survey

Abstract

Scenario languages are widely used in software development. Typical usage scenarios, forbidden behaviors, test cases, and many more aspects can be depicted with graphical scenarios. Scenario languages were introduced into the Unified Modeling Language (UML) under the name of Sequence Diagrams. The 2.0 version of UML changed Sequence Diagrams significantly and the expressiveness of the language was highly increased. However, the complexity of the language (and the diversity of the goals Sequence Diagrams are used for) yields several possible choices in its semantics. This paper collects and categorizes the semantic choices in the language, surveys the formal semantics proposed for Sequence Diagrams, and presents how these approaches handle the various semantic choices.

Stepwise refinement of sequence diagrams with soft real-time constraints

“…A recent survey of different semantics for UML 2.x sequence diagrams is given by Micskei and Waeselynck in [18]. Probabilities are not covered, as they are not included in the UML 2.x standard.…”

“…Probabilities are not covered, as they are not included in the UML 2.x standard. In [12], we have compared STAIRS and its refinement relations to related work on sequence diagrams, including the most relevant from [18], as well as other similar notations, refinement and nondeterminism. The discussion in this section is therefore restricted to aspects concerning time and probabilities.…”

TERMOS: A Formal Language for Scenarios in Mobile Computing Systems

“…We had a thorough look at existing semantics for UML 2.0 Sequence Diagrams [9]. We also looked at other scenario languages distinguishing potential and mandatory behavior, which makes them well suited for the expression of properties [10,11].…”

“…We surveyed the existing formal semantics proposed for Sequence Diagrams [9]. It turned out that many semantic choices exist even for simple diagrams and elements, e.g., whether a diagram is a complete or a partial interaction or how a trace is represented.…”

“…If more complex language elements are allowed which can express alternatives or negation, it becomes harder and harder to decide whether a given execution trace conforms to a scenario. Therefore we selected those options for TERMOS from the choices collected in [9] which make checking of traces possible, and added further syntactic restrictions. This section highlights these design decisions (for a complete list see [5]).…”