Alan Stewart Maurice Clint Terry Harmer Peter Kilpatrick Ronald H. Perrott Joaquim Gabarró Assessing the Reliability and Cost of Web and Grid Orchestrations. 428-433 2008 ARES http://doi.ieeecomputersociety.org/10.1109/ARES.2008.39 conf/IEEEares/2008 db/conf/IEEEares/ares2008.html#StewartCHKPG08