CWL

Fig. 1. CWL import

Fig. 2. CWL analysis

Fig. 3. CWL workflow

Fig. 4. CWL execution

The Common Workflow Language (CWL) is an open standard for describing analysis workflows and tools in a way that makes them portable and scalable across a variety of software and hardware environments, from workstations to cluster, cloud, and high performance computing (HPC) environments (CWL website).

Standard describes execution of Command Line Tools including setting of arguments, environment requirements and conditions (e.g. execution in docker or remote server). It also describes workflow scenarios combining several tools through their inputs and outputs.

Currently BioUML supports next features:

• Import of CWL command line tools and workflows. Representing them as data elements in BioUML repository (fig. 1).
• Representing of CWL files as analysis methods within BioUML interface (fig. 2).
• Visual representation of CWL workflows as visual diagrams (fig. 3).
• Setting of parameters and execution of CWL worklfows and tools. Produced result is stored in BioUML repository (fig.4).
• Execution is performed with reference implementation of CWL - cwltool, thus we support all features supported by it.

Currently there are several limitations in CWL support which we plan to overcome in future:

• CWL tools may be imported only in designated folder within BioUMl interface. (Workflows can be imported anywhere)
• Only workflows referencing separate cwl files as their steps can be imported
• Referenced cwl files should be preliminary imported before the workflow
• Visual diagram is used only for representation of CWL scenario and can not be edited
• BioUML workflows supports only files outputs and inputs. Strings, numerical and boolean values are not represented in visualisation
• Started execution of CWL scenario or tool can not be stopped manually until it is finished