Business Process Management (Part-2 Business Process Modelling[Chapter III Business Process Modelling Foundation ] ) Sec I -- By Mathias Weske

Workflow Data Patterns

To organize data-related issues in business process management, workflow
data patterns have been introduced. Workflow data patterns formulate characteristics
on how to handle data in business processes. They are organized
according to the dimensions data visibility, data interaction, data transfer,
and data-based routing.
Data visibility is very similar to the concept of scope in programming
languages because it characterizes the area in which a certain data object is
available for access. The most important workflow data patterns regarding
data visibility are as follows.
• Task data: The data object is local to a particular activity; it is not visible
to other activities of the same process or other processes.
• Block data: The data object is visible to all activities of a given subprocess.
• Workflow data: The data object is visible to all activities of a given business
process, but access is restricted by the business process management
system, as defined in the business process model.
• Environment data: The data object is part of the business process execution
environment; it can be accessed by process activities during process
enactment.
Data interaction patterns describe how data objects can be passed between
activities and processes. Data objects can be communicated between activities
of the same business process, between activities and subprocesses of the same
business process, and also between activities of different business processes.
Data can also be communicated between the business process and the business
process management system.
Data transfer is the next dimension to consider. Data transfer can be
performed by passing values of data objects and by passing references to data
objects. These data transfer patterns are very similar to call-by-value and callby-
reference, concepts used in programming languages to invoke procedures
and functions.
In data-based routing, data can have different implications on process
enactment. In the simplest case, the presence of a data object can enable
a process activity. Data objects can also be used to evaluate conditions in
business process models, for instance, to decide on the particular branch to
take in a split node.
Workflow data patterns are an appropriate means to organize aspects of
business processes related to the handling of data.