Introduction
SharePoint 2010 introduces many new capabilities that are categorized into six different workloads, one of which is the composites workload. A key component of creating composite applications is SharePoint 2010’s ability to create custom workflows, allowing end users to attach behaviour to data.
Workflows in SharePoint Server 2010 enable enterprises to reduce the amount of unnecessary interactions between people as they perform business processes. For example, to reach a decision, groups typically follow a series of steps. The steps can be a formal, standard operating procedure, or an informal implicitly understood way to operate. Collectively, the steps represent a business process. The number of human interactions that occur in business processes can inhibit speed and the quality of decisions.
Workflow in SharePoint 2010
SharePoint Foundation 2010 workflows are made available to end-users at the list or document-library level. Workflows can be added to documents or list items. Workflow can also be added to content types. Multiple workflows may be available for a given item. Multiple workflows can run simultaneously on the same item, but only one instance of a specific workflow can run on a specific item at any given time. For example, you might have two workflows, called
SpecReview and LegalReview, available for a specific content type, Specification. Although both workflows can run simultaneously on a specific item of the Specification content type, you cannot have two instances of the LegalReview workflow running on the same item at the same time.
The figure below illustrates the conceptual workflow architecture in SharePoint Foundation. Each content type, list, and document library in the farm is linked to the workflows added to it through the workflow association table. Each workflow has a workflow definition. This XML definition specifies the identity of the actual workflow assembly, and class within that assembly, as well as the location of any workflow forms the workflow needs to run.
SharePoint Workflow Life Cycle
The figure below illustrates the four stages of the SharePoint workflow life cycle. These stages allow for the assignment of workflows to content type, handle the different ways for starting workflows, and keep the workflow infrastructure flexible during execution. This custom life cycle is provided by the SharePoint-specific workflow hosting environment. During some of the following stages, forms can be used to gather additional user input as parameters, which are required for this stage to execute.
