Describe typical scenarios with a visual trace language

The MSC Editor is a graphical tool for handling Message Sequence Charts (MSCs), supporting the graphical notation defined in the standard Z.120. The charts are used early in the development process as use cases. Later, automatically generated MSCs serve as a powerful graphical trace tool when simulating a system specified in SDL. Telelogic® SDL Explorer™ can take an MSC that you create and test it against your SDL system to find out whether your MSC describes a possible behavior in your system.

High-level Message Sequence Charts (HMSCs) - or "Road maps" as they sometimes are called - give users the possibility of building hierarchies of MSCs. Instead of drawing different MSCs for situations where perhaps just a single condition separates two cases, an HMSC can be drawn that describes alternative paths.