Service Composition - Guide to Cloud Computing for Business and Technology Managers - page 214

physical objects are passed from one processing step to another. Workflow
is a concept that links together technologies and tools able to automatically
route events and tasks with programs or users.
Process-oriented workflows are used to automate processes whose struc-
ture is well defined and stable over time, which often coordinate subpro-
cesses executed by machines and which only require minor user involvement
(often only in specific cases). An order management process or a loan request
is an example of a well-defined process. Certain process-oriented workflows
may have transactional properties. The process-oriented workflow is made
up of tasks that follow routes, with checkpoints represented by business
rules, for example, pause for a credit approval . Such business process rules gov-
ern the overall processing of activities, including the routing of requests, the
assignment or distribution of requests to designated roles, the passing of
workflow data from activity to activity, and the dependencies and relation-
ships between business process activities.
A workflow involves activities, decision points, rules, routes, and roles.
These are briefly described later. Just like a process, a workflow normally
comprises a number of logical steps, each of which is known as an activity .
An activity is a set of actions that are guided by the workflow. An activity
may involve manual interaction with a user or workflow participant or might
be executed using diverse resources such as application programs or data-
bases. A work item or data set is created and is processed and changed in
stages at a number of processing or decision points to meet specific business
goals. Most workflow engines can handle very complex series of processes.
A workflow can depict various aspects of a business process including auto-
mated and manual activities, decision points and business rules, parallel and
sequential work routes, and how to manage exceptions to the normal busi-
ness process. A workflow can have logical decision points that determine which
branch of the flow a work item may take in the event of alternative paths.
Every alternate path within the flow is identified and controlled through a
bounded set of logical decision points. An instantiation of a workflow to sup-
port a work item includes all possible paths from beginning to end.
Within a workflow, business rules in each decision point determine how
workflow-related data are to be processed, routed, tracked, and controlled.
Business rules are core business policies that capture the nature of an enter-
prise's business model and define the conditions that must be met in order
to move to the next stage of the workflow. Business rules are represented as
compact statements about an aspect of the business that can be expressed
within an application, and as such, they determine the route to be followed.
For instance, for a health-care application, business rules may include poli-
cies on how new claim validation, referral requirements, or special proce-
dure approvals are implemented. Business rules can represent among other
things typical business situations such as escalation (“send this document
to a supervisor for approval”) and managing exceptions (“this loan is more
than $50,000; send it to the MD”).