A framework for workflow interoperability
1st October 2005 to 31st December 2009
Over the past two decades, a significant variety of different workflow definition languages (WDLs), and associated tools,
have appeared. As the importance of workflow languages increases in both commercial and scientific contexts, requirements
to check properties of workflows, and compositions thereof, are starting to emerge. A lack of formal foundations means
that constructing and reasoning about compositions of workflows written in different languages is an extremely difficult task,
resulting in limited interoperability. While
standards exist that aim to establish interoperability, each workflow-related product that emerges tends to create its own WDL that is designed to meet specific requirements. Most attempts at attaining interoperation among workflow systems have been limited to achieving run-time interoperability, through the invocation of applications on remote workflow engines using API calls. The focus of this project is the development of an alternative approach—with interoperation being achieved during build-time. The advantage of having build-time interoperability is that users can also modify workflows according to their needs before submitting them for execution, with the added benefit of being able to reuse existing workflows written in other WDLs. Moreover, this gives rise to the possibility of combining pre-defined workflows made available from a variety of systems to compose a solution that closely fits their needs. A formal framework for interoperability is a fundamental first step in allowing workflows written in different languages to be composed in an effective fashion. To this end, we have developed the Intermediate Workflow Representation Language (IWRL) to act as an intermediary to carry out languageto- language conversions. The main benefit of our approach is that legacy workflows, defined in different workflow definition languages, might be used in conjunction—and in a fashion that is seamless to the user.
standards exist that aim to establish interoperability, each workflow-related product that emerges tends to create its own WDL that is designed to meet specific requirements. Most attempts at attaining interoperation among workflow systems have been limited to achieving run-time interoperability, through the invocation of applications on remote workflow engines using API calls. The focus of this project is the development of an alternative approach—with interoperation being achieved during build-time. The advantage of having build-time interoperability is that users can also modify workflows according to their needs before submitting them for execution, with the added benefit of being able to reuse existing workflows written in other WDLs. Moreover, this gives rise to the possibility of combining pre-defined workflows made available from a variety of systems to compose a solution that closely fits their needs. A formal framework for interoperability is a fundamental first step in allowing workflows written in different languages to be composed in an effective fashion. To this end, we have developed the Intermediate Workflow Representation Language (IWRL) to act as an intermediary to carry out languageto- language conversions. The main benefit of our approach is that legacy workflows, defined in different workflow definition languages, might be used in conjunction—and in a fashion that is seamless to the user.