Searching workflows with hierarchical views

Workflows are prevalent in diverse applications, which can be sci- entific experiments, business processes, web services, or recipes. With the dramatically growing number of workflows, there is an increasing need for people to search a workflow repository using keywords and to retrieve the relevant ones. A workflow hierarchy is a three dimensional object containing multiple abstraction views of different granularity on the same workflow. This unique struc- ture poses a new set of challenges compared to keyword search on tree or graph structures typically found in relational or XML data. In this paper, we define an informative, self-contained and con- cise search result on workflows to be a projection of a workflow hierarchy on a two dimensional viewing plane inferred from user queries. We then design and develop an efficient keyword search engine for workflows. Experimental evaluation demonstrates the effectiveness of our approach.