We present a case study to illustrate our formalism for the specification and verification of the method-invocation behavior of web-service applications constructed from asynchronously interacting multi-threaded distributed components. Our model is expressive enough to allow the representation of recursion and dynamic thread creation, and yet permits the algorithmic analysis of the following two questions: (1) Does a given service satisfy a safety specification? (2) Can a given service be substituted by a another service in an arbitrary context? Our case study is based on the Amazon.com E-Commerce Services (ECS) platform.

A key problem for effective unit testing is the dificulty of partitioning large software systems into appropriate units that can be tested in isolation. We present an approach that identifies control and data inter-dependencies between software components using static program analysis, and divides the source code into units where highly-intertwined components are grouped together. Those units can then be tested in isolation using automated test generation techniques and tools, such as dynamic software model checkers. We discuss preliminary experimental results showing that automatic software partitioning can significantly increase test coverage without generating too many false alarms caused by unrealistic inputs being injected at interfaces between units.

We present a language for specifying web service interfaces. A web service interface puts three kinds of constraints on the users of the service. First, the interface specifies the methods that can be called by a client, together with types of input and output parameters; these are called signature constraints. Second, the interface may specify propositional constraints on method calls and output values that may occur in a web service conversation; these are called consistency constraints. Third, the interface may specify temporal constraints on the ordering of method calls; these are called protocol constraints. The interfaces can be used to check, first, if two or more web services are compatible, and second, if a web service A can be safely substituted for a web service B. The algorithm for compatibility checking verifies that two or more interfaces fulfill each others' constraints. The algorithm for substitutivity checking verifies that service A demands fewer and fulfills more constraints than service B.

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RTL descriptions for word-level arithmetic components typically specify the architecture at the bit-level of the registers. The problem studied in this paper is to abstract the word-level functionality of a component from its bit-level specification. This is particularly useful in simulation since word-level descriptions can be simulated much faster than bit-level descriptions. Word-level abstractions are also useful for reducing the complexity of component matching since the number of words is significantly smaller than the number of bits. This paper presents an algorithm for abstraction of word-level linear functions from bit-level component descriptions. We also present complexity results for component matching which justifies the advantage of performing abstraction prior to component matching.