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7 The Architecture 213
7.3.2 The Editor

The YAWL Editor (sometimes referred to as the Process Designer) is a design
environment for the creation and verification of YAWL process specifications. It
is packaged as a Java desktop application, as opposed to the other YAWL System
services that are packaged as web services. It communicates with a running Engine
through Interface A to obtain a list of the YAWL Services currently registered with
the Engine, to be used when associating a task with a service. It also communicates
with a running Resource Service through Interface R (described in Sect. 7.3.3) to
obtain lists of the various organizational resources and codelets currently available,
so that selected resources can be associated with particular tasks.
The Editor provides a tool palette from which modeling elements (such as
tasks and conditions) may be chosen for placement on the design canvas. Rout-
ing constructs may be added to tasks and arcs added to join tasks and conditions
to form a complete workflow graph representing a particular business process. At
any time, a process may be verified and analyzed using various algorithms to ensure
completeness, soundness, and so on.
When complete, the process definition may be saved to a disk file, which will
contain an XML representation of the specification conforming to the YAWL spec-
ification schema. A specification file may be selected by a YAWL Service for
deployment into the Engine, which is achieved by either passing a reference to the
file, or its actual contents, via the appropriate method of Interface A.
The Editor is described in more detail in Chap. 8.

7.3.3 Resource Service

The basic role of the Resource Service is to allocate enabled work items to resources
so that they can be processed. To fully enable all of the resource management pat-
terns supported by the YAWL System, there are four sub-services falling under the
umbrella of the Resource Service:
a Resource Manager, which manages the allocation of resources to work items
a Worklist Handler, a web-form based user interface that provides users with the
ability to interact with and process work items
a Forms Connector; while the Worklist Handler includes a dynamic web-form
generator for the display and editing of work item data, designers may choose to
implement specialized forms for particular work items – these forms are managed
by this service
a Codelet Service that maintains and executes codelets selected for automated
tasks

Resources may be people or may be an application, service, or codelet of some
kind. At design time, each task in a specification may be marked as manual (requir-
ing a human resource) or automated (requiring a non-human resource). In the