Workflow engines like Taverna provide a means to connect the data flows of smaller applications. Jobs to be executed on computational grids may be interpreted as such separate entities and it appeals to assemble these graphically to larger solutions. The UseCases specify how to use programs. There is no direct link to grid computing, except for the specification of Runtime Environments that are required for the execution of the job. A development within the KnowARC project allows for their automated installation (dre.knowarc.eu). Instructions on preparing Taverna for utilising these Use Cases are given on taverna.nordugrid.org.
One needs to login to the system to have the right to edit the data. Every use case is assigned a maintainer. In the current setup, this is only an informal arrangement and no changes should be performed on a entry by anybody other than the maintainer him- or herself. A click on the maintainer will provide contact information.
The ID identifies the program as a use case. Different versions or differences in the way a particular program is used, will most likely demand the specification of multiple use cases for the same runtime environment. These fields help with the presentation in this database, however, for Taverna, only the entry to the field 'xml' is relevant.
This field comprises all the information that is required for Taverna to
<program name="name of program" description="short description to appear in Taverna"
command="command line of that use case, e.g. 'wc inputfile > outputfile'">
<output name="name of slot that represents the output in the workflow">
<fromfile path="name of file that is produced by the command line, here 'outputfile'" />
</output>
<input name="multiple_sequences_FASTA">
<file path="input" />
</input>
<RE name="specification of runtime environment, none required for the given
example, a possible value would be 'APPS/BIO/CLUSTALW-1.8.3'" />
<RE name="multiple entries are possible"
</program>