New Features: - YAWL

New Features:
For Workflow Users:
As of Beta 8
The next iteration of the Worklet Service, which has been completely redeveloped
and now includes a dynamic exception handling service which leverages off the
worklet selection approach and monitors for and manages process exceptions, based
on case contexts, in real time. There have also been improvements made to the SMS
service and general bug fixes and refactors.
As of Beta 7.2
Improved administration functionality, and bug fixes. Reporting functionality in the
administration tool now includes the ability to create charts and tables for reporting
previous executions of cases and tasks.
As of Beta 7.1
Greater robustness and enterprise readiness. Stand alone version is easier to install.
Improvements to diagnostic reporting when processes are loaded into engine.
As of Beta 7
This version includes the first release of a custom service called the Worklet Dynamic
Process Selection Service (workletSelector.war), which is designed to provide the
ability to substitute a workitem in a YAWL process with a dynamically selected
"worklet" - a discrete YAWL process that acts as a sub-net for the workitem and so
handles one specific task in a larger, composite process activity.
Several bug fixes and enhancements are also in this release.
As of Beta 6
Beta 6 features a modified worklist service (worklist.war). This service is able to
allocate workitems to users according to organisational rules. Therefore process
modellers can define who is able to perform different tasks in a process. This concept
is termed the “Resource Perspective”.
The system is more rigorously built and tested. Persistence is improved to work with
Postgres and hibernate, and it is more robust.
As of Beta 5
Beta 5 features a new custom YAWL service. This YAWL service is capable of
sending, receiving, SMS messages from process instances. It can correlate SMS

send-replies with process instances automatically. Furthermore it is
model/demonstration of how to create and deploy custom YAWL services.
As of Beta 4
Persistent storage of workflow state is now possible.
Automatically generated Forms for editing workitems.
XML Schema integration allows process modellers to incorporate data types into
process specifications.
Features a new GUI based, stand-alone, process engine for testing and running non
distributed process specifications.
Tomcat environment provides better feedback to assist deployment and configuration.
Recursive decomposition is now possible from all levels of a process hierarchy.
Engine is fully backwards compatible with the Beta 2 & Beta 3 releases for YAWL.
Process definitions written in this format can still be loaded and run in the engine.
There are new detection algorithms that discover problems with process specifications
during runtime and they provide runtime feedback to the user. Once these errors are
detected a diagnostic message is sent to the user that provides information about what
went wrong due to a specification error. This feature is activated after starting a task,
and after completing a task, and also after completing a multiple instance task.
New page in Worklist application provides diagnostic information about why user
inputted data failed to pass validation, and how to correct the problem.
Strong typing: runtime validation of user inputted data for both case launching, and
for task completion.
Web applications are much more robust.
For Developers:
As of Beta 8
To facilitate the creation of the worklet exception service, a new interface to the
YAWL engine (Interface X) has been developed. This interface notifies custom
services of particular events during the lifecycle of a process instance where
exceptions may have occurred or can be tested for. See the document
Interface_X_Developers_Guide for more details.

As of Beta 7.1
Code is slightly cleaner, safer. Easier to deploy and build with. ObserverGateway
system allows plug-in connectivity of tasks to custom code, without the need for
YAWL Custom Web Services.
As of Beta 7
Interface B has a new Complete Case event, which notifies custom services when a
case has been completed. To receive these events, the service must register with the
engine as an ‘observer’ for the event on a case by case basis.
As of Beta 6
Hibernate is more effectively used.
Database is configured off, but is fairly simple to configure connectivity with
Postgres, by editing the persistence enabled flag within ‘web.xml’ files of webapplication
files.
System restore is improved for engine reloading after failure.
If persistence is configured on, and it fails then the engine will stop.
As of Beta 5
I extended the yawlWSInvoker component so that it can invoke WSDL described
Web services that are slightly more sophisitcated, such the new Barnes and Noble
Web service.
I also refactored the module to use task information in a different way, in order to find
information about the Web service. Such information used to be stored in special
fields, but now it is stored as basic variables inside the task, passed to the WSInvoker.
These have reserved names that the yawlWSInvoker module is looking out for. I also
made some significant changes to the Barnes and Noble process specification, in
accordance with the new refactoring.
Refactored the way Custom YAWL Services are built making them easier to deploy.
This consisted of removing some methods related to authenitcation from
InterfaceB_EnvironmentBasedServer, that din't really belong there. I put them into a
new class called Authentication Response Servlet. This servlet is designed to be
loaded and running from an appropriately configured web.xml file. See YAWL
WSInvoker module's web.xml file as an example of this configuration.
The other refactoring I did for Custom YAWL Services makes it fairly easy to add a
Service welcome html page. I added method which I called "doGet()" to the
InterfaceBWebsideController abstract class. This way when builders of custom
YAWL Services extend this class with versions of their own they can implement this
method to make a better looking cusotm YAWL Service.
Make custom YAWL services easier to write.

I was writing a custom YAWL application for SMS development and found ways of
making it much simpler to write. I added two new utility methods to
InterfaceBWebsideController to assist developers with this.
public Element prepareReplyRootElement(WorkItemRecord enabledWorkItem,
String sessionHandle)
protected List checkOutAllInstancesOfThisTask(WorkItemRecord
enabledWorkItem, String sessionHandle)
Also refactored the checkIn workitem method
public String checkInWorkItem(String workItemID, String inputData, String
outputData, String sessionHandle)
It now takes org.jdom.Element as input and output data params. This was noted by
Stephan as being desireable because it is not clear that the string params have to be
formatted as XML. I replaced the old method signature implementation with one that
calls the new implementation and then deprecated it. This way existing users are not
going to have to recompile thier code to work with this change to YAWL.
As of Beta 4
There is a new XML process definition format, (includes data typing).
Features a new interface on the administrate page of the process engine (when
running on Tomcat). It allows for easy addition of custom YAWL services.
Interface `A' and 'B' are now easier to exploit for developing custom YAWL services.
Critical areas such as the InterfaceB classes are fully Javadoc'ed.
We overhauled the exceptions hierarchy, including new compensation strategies, and
in some cases rollback of process state.
Caching was reduced, ensuring that the runtime data is more consistent.
During deployment the worklist YAWL service can be hot swapped without causing
problems for the system.
Improved build scripts are more self contained, more stable, and faster.
Improved test files catch more errors.
There is new xml syntax.
Output parameters are used for both atomic task and composite task decompositions.
There is a simpler and more intuitive way of accessing the state space of data
variables.
Unnecessary caching of workitem inside the system has been mitigated.

APIs for Interfaces A & B are more stable and more mature.
For Researchers:
As of Beta 8
Reworking of the Worklet Service with added support for dynamic exception
handling.
As of Beta 7
New Worklets custom service.
As of Beta 6
New Resource perspective.
As of Beta 5
New pure control flow task data pattern. i.e. an input variable of a task can
effectively be processed within the workflow engine, and should not be passed to a
service or sub-process.
Bugs fixed:
As of Beta 7.1
Multiple instance atomic tasks with dynamic instance creation do not experience
failures during execution. Deadlocked processes are reported to the logger and the
database.
As of Beta 6
Fixed failure to effectively report problems in a process specification.
Fixed failure of engine to effectively handle and propagate case cancellation to
custom services.
Fixed problem with the caching of workitems in custom YAWL services using
InterfaceBWebsideController.

As of Beta 5
In Response to BUG report by Andrew Hastie: Fixed propagation of task cancellation
so that events are sent to custom YAWL services. This was a functionality bug and
required considerable number of problem layers to be resolved.
Bug fixed. When running a beta 4 process with empty tasks, system threw a runtime
exception once trying to run the task. This was fixed by adding some guards to data
processing code to check for the presence of a task decomposition.
Bug fixed. When attempting to check in a work item from a yawl service, if the item
is cancelled then the worklist throws a runtime exception. This was fixed by caching
all active work items in the custom yawl service and letting the engine catch and
report the discrepancy.
Fixed decompositionID of beta 4 XML Schema so that it is now constrained by
NCName, previously a string.
As of Beta 4
After unloading a specification the 'Workflow Specifications' page used to hide the
specification even if there were still active, incomplete cases. Now the unloading of a
specification will still allow existing cases to complete undisturbed.
Active tasks of running cases are now cleaned up when the case gets cancelled.
Bug Fix: Connect method of Interface A now operational.
Bug Fix: Engine state is fully aligned with the work items announced to users.