Conceptual Model and Terminology
While the terms mentioned have been used in the previous chapters informally, the concepts behind these terms and their relationships will now be discussed in more detail, using conceptual
models. These models are expressed in the Unified Modeling Language, an
object-oriented modelling and design language.
Business processes consist of activities whose coordinated execution realizes
some business goal. These activities can be system activities, user interaction
activities, or manual activities. Manual activities are not supported by
information systems. An example of a manual activity is sending a parcel to
a business partner.
User interaction activities go a step further: these are activities that knowledge
workers perform, using information systems. There is no physical activity
involved. An example of a human interaction activity is entering data on an
insurance claim in a call centre environment. Since humans use information
systems to perform these activities, applications with appropriate user interfaces
need to be in place to allow effective work. These applications need to
be connected to back-end application systems that store the entered data and
make it available for future use.
Some activities that are conducted during the enactment of a business
process are of manual nature, but state changes are entered in a business
process management system by means of user interaction activities. For instance,
the delivery of a parcel can be monitored by an information system.
Typically, the actual delivery of a parcel is acknowledged by the recipient
with her signature. The actual delivery is important information in logistics
business processes that needs to be represented properly by information systems.
There are several types of events during a logistics process. These events
are often available to the user as tracking information. While the activities
are of manual nature, an information system—the tracking system—receives
information on the current status of the process.
System activities do not involve a human user; they are executed by information
systems. An example of a system activity is retrieving stock information
from a stock broker application or checking the balance of a bank
account. It is assumed that the actual parameters required for the invocation
are available. If a human user provides this information, then it is a user
interaction activity. Both types of activities require access to the respective
Certain parts of a business process can be enacted by workflow technology.
A workflow management system can make sure that the activities of a business
process are performed in the order specified, and that the information systems
are invoked to realize the business functionality. This relationship between
business processes and workflows is represented by an association between
the respective classes. We argue that workflow is not a subclass of business
process, since a workflow realizes a part of a business process, so a workflow
is not in an “is-a” relationship with a business process, but is an association.
With regard to the types of activities mentioned, system activities are associated
with workflows, since system activities can participate in any kind
of workflow, system workflow or human interaction workflow. User interaction
activities and manual activities, however, can only participate in human