Workflows

Workflows is a generic realization of the process model. It contains a set of classes that serve as the basis for describing many activities we might perform with data. Specialized of classes within the process model may exist for specific applications or use cases.

The exchange currency of Workflows are variables and values. With their output and input parameters WorkflowSteps are able to exchange variables and values with each other. This type of exchange is akin to "message flow" in the Business Process Model and Notation (BPMN).

Many of the Workflows classes represent standard process flows such as used in programming flow charts and questionnaire design. These include standard conditional routing steps such as IfThenElse, Loop, etc. These classes were largely derived from the OWL-S process model.

The entry point to Workflow is the WorkflowProcess. A WorkflowProcess has a WorkflowStepSequence. This class can be used to string together a series of WorkflowSteps. A WorkflowStep is abstract. Implementations include both control constructs and "atomic" acts. WorkflowSteps typically terminate in one or the other of these acts.

ComputationAction is a code sequence. Code sequences are typically developed in statistical packages like Stata, R and SAS. They perform data management and data transformation activities. The C2Metadata Project is able to represents code commands in DDI using many of the constructs in this package.

Alternatively, MetadataDrivenAction was specifically developed for the Extract, Transform and Load (ETL) use case. ETL platforms are menu and dialog driven. Users interact with the platform to produce metadata that the platform in turns executes. There is no coding by and large although for legacy purposes ETL platforms are able to run scripts developed for statistical packages like Stata, R and SAS.

Other specialized acts include cover different forms of data capture, instructions, etc.

Besides being the Workflows entry point, WorkflowProcess is also where the Methodology Pattern ends and Workflows begins. This means that realizations of the Methodology Pattern may link to either a generic WorkflowProcess or specialized sub-type of that class.

Namespace URI: 
http://ddialliance.org/ddi4/ProcessCore
Color of objects in the uml graph: 
000000
Example: 
Workflows can be used to describe how the sequence of questions in a questionnaire is to be determined. This is prospective. A prospective Workflows can be used by a questionnaire system to actually assist in the execution of an interview. Workflows in a questionnaire can also be retrospective. Workflows can record the actual flow of an interview. Workflows can describe data transformation processes through the subtype BusinessProcess.
Explanatory Notes: 
WorkflowStepSequence is a SimpleCollection to support the data capture use case. It has been extended with StructuredWorkflowSteps to support the data transformation use case as needed. In this extension StructuredWorkflowSteps takes a WorkflowStepRelationStructure able represent complex temporal relations between WorkflowSteps characteristic of data management use cases where there are many "reads", "writes" and "joins" that together define complex data flows.
Include in build?: 
True

Comments

I just added this additional realization to Workflow Sequence, it was missing.

added the sequence order to the workflow sequence. If this should be outside of the workflow sequence it needs a means of being bound into the workflow sequence

Package Graph