In direct allocation, an individual person, rather than a position in an organization,
is allocated to all activity instances of a particular activity model. This
resource allocation is useful in cases where there is exactly one person who is
suitable for performing these activities, such as the chairperson of a company,
who has to finally decide on investments exceeding a certain threshold.
Direct allocation can always be simulated by role-based allocation, discussed
next, simply by providing a role with one member, in our example
the company owner. However, if this property of the organization will remain
stable over a long period of time, introducing a separate role (owner) is not
required, so direct allocation can be used. The limitations of direct allocation
will be discussed in the context of role-based allocation.
Role-based allocation is the standard way of allocating work to the members of
organizations. It is based on the understanding that all members of a certain
role are somehow functionally equivalent, so that any member of the role can
perform a given unit of work.
To each activity model in a business process model, a is role assigned,
indicating that all members of the role are capable of performing the respective
activity instances. The mapping of role information to specific knowledge
workers is called role resolution. Current information on the availability of the
knowledge worker is used during role resolution.
There are two ways of realizing role-based allocation. In the first way, when
an activity instance enters the ready state, the work item is communicated
to the members of the group. Once one member of the group selects a work
item, the work items associated with the other group members are deleted. In
the second way, only one person is selected to perform the activity instance,
so only one work item is created.
Role-based allocation provides a set of interesting advantages with respect
to direct allocation, all of which are related to enhancing the flexibility of
business processes. Firstly, the business process model does not need to be
changed when there are changes in the personnel, i.e., employees retire and
new employees are hired. When using direct allocation, any change in the personnel related to the directly allocated persons would result in a change in
the business process model.
Secondly, by role resolution at run time of the business process, only available
persons are selected to perform activities. This approach avoids situations
in which persons are selected to perform activity instances that are currently
not available, for instance, due to meetings or absence. In direct role resolution,
when the person is not available, there is no way of continuing the