A Query-Driven Simulation (QDS) system Cassandra+ is described that allows end-users to ask temporal queries about outcomes of running simulation models written in various simulation languages. The architecture of Cassandra+, its query language SimQL, and the implementation of the system are described. It is argued that Cassandra+ provides a more effective information systems support for simulations than the more traditional approaches by letting the users ask questions of interest about simulation outcomes in a declarative, flexible, and interactive fashion. To demonstrate the usefulness and practicality of the QDS approach and Cassandra+ in particular to asking queries about simulation outcomes, we present a case study. In this case study, we show how Cassandra+ performs on an ‘industrial-strength’ manufacturing application developed by the management consulting company of Booz, Allen & Hamilton.
