Our paper, Understanding the Cost of Semantic Composability Validation, will appear in the proceedings of PADS 2011!

Abstract: Validation of semantic composability is a non-trivial problem and a key step in component-based modeling and simulation. Recent work in semantic composability validation promise to reduce verification, validation, and accreditation efforts. However, the underlying cost of current validation approaches can undermine the promised benefits, and the trade-off between validation accuracy and validation cost is not well understood. In this paper we present, to the best of our knowledge, the first quantitative study on the cost of validating semantic composability. Firstly, validation approaches are categorized into techniques that validate general model properties, and that compare the composed model execution with a reference model. Secondly, we focus on two key factors that influence validation cost: characteristics of the simulation problem and the validation approach adopted. Our study covers four representative validation approaches, two DEVS-based approaches, the Petty and Weisel formal validation, and deny-validity, and for simplicity, we use computation time as a measure of validation cost. Based on a queueing model with 1,000 components, the cost ratio between validating general model properties and model execution is 55:45. A 10% increase in the complexity of the composition structure, such as fork and join component interconnections, increases validation cost by more than half. In model execution validation, there is a trade-off between validation accuracy andvalidation cost, with the time-based deny-validity approach costing seven times that of timeless Petty and Weisel formalism.