Change-Resilient Scientific Workflow Systems with Automated Optimization OR: Bringing together formal methods of databases and programming languages to build change-resilient distributed XML stream processing systems whose execution can be automatically parallelised and optimized by the execution environment Daniel Zinn, UC Davis I will present recent work in that area and outline future research potential. The following abstract gives more concrete information about my talk and our current work. We propose a new stream-processing framework based on a virtual assembly line model. We instantiate the "Virtual Assembly Line" framework obtaining \Delta-xml, an approach for designing and optimizing distributed XML processing pipelines. \Delta-xml greatly simplifies the design of change-resilient dataflow pipelines: XML processors (called actors) can be inserted, deleted, and their ``scope of work'' (the parts of the stream they can read from and write to) changed freely, without compromising the overall process pipeline design. Unlike conventional approaches that rely on adapters to ``glue'' together processing components, our actors employ flexible configurations that select only relevant portions of the input stream. \Delta-xml pipelines are not only more flexible and change resilient than current approaches, but can also be optimized by compiling them into dataflow process networks that minimize shipping cost in distributed settings: Using a static type inference approach based on regular expression types for XML, we show how to perform a dataflow analysis to determine XML stream fragments that are relevant to an actor, allowing irrelevant fragments to be bypassed (``shipped'') to downstream actors. We also show that our approach is optimal for distributed XML pipelines, given the type information available in \Delat-xml.