Speaker: Dirk Fahland, Eindhoven University of Technology

Title:  From scenarios to distributed components: LSC revisited

Abstract:  Scenario-based techniques such as Message Sequence Charts
(MSC) and Live Sequence Charts (LSC) are a technique to specify
behavior of complex, distributed systems in an intuitive manner,
particularly at early stages of system design. Despite its intuitive
nature, the technique poses some challenges. The most prominent is to
automatically synthesize an operational system model (a statechart or
a Petri net) from a given specification; the model can then serve as a
blue print for implementation in hard- and software. While MSC are
essentially too weak to specify complex systems, LSCs are too strong:
synthesis of components of a distributed system fails.

In my talk, I will reconsider the semantics of LSC-style scenarios
regarding expressive power, ability to specify distributed behaviors
and solving the synthesis problem. I will show that by changing the
interpretation of LSC from linear time to simple branching time
semantics, one obtains a simple, yet very expressive and intuitive
scenario-based specification language. By choosing partial orders
instead of sequential runs as semantic domain, one can faithfully
specify the behaviors of a distributed system. We call this notation
distributed LSC (dLSC). As the main result, I will present a complete
technique for synthesizing Petri net components from any given dLSC
specification, in polynomial time.


Bio:
Dirk Fahland is assistant professor at the Eindhoven University
of Technology, the Netherlands in the group of Prof. Wil van der
Aalst. He obtained his PhD at the Humboldt-Universität zu Berlin,
Germany. His research interests are specifying and synthesizing
distributed systems and the automatic discovery of system
specifications and models from execution logs.