ProcessWeb
ProcessWeb is a system designed to provide active process
modelling and co-ordination via the World Wide Web. At its core is the
ProcessWise Integrator
system, developed during the IPSE 2.5 project and later
by TeamWARE,
which provides an environment for enacting process models written in PML
(Process Management Language). ProcessWeb was originally developed in 1997,
building on earlier work in the late 1980s, and continues to be novel in the way that it
continually evolves as users create new process models. In ProcessWeb all
process models are created as an incremental change to the running system.
ProcessWeb is developed and maintained by the Informatics
Process Group at the School
of Computer Science, University of
Manchester.
Since January 1999 ProcessWeb system has been available for public use over
the internet. If you wish to try ProcessWeb you should consult the
sections Using ProcessWeb and
Creating
and Using ProcessWeb models on this page.
Further information
Documentation
There is limited
documentation available. However, we are always trying to improve the
existing documentation and keep up to date with new ProcessWeb developments.
For developers, a reference guide to ProcessWeb is
under construction. This includes some example ProcessWeb models.
The online reference guide mentions some further
documentation about the underlying
ProcessWise Integrator
system .
The CS637 Process Modelling module
MSc page may also be a useful online resource. For example, the section on
possible ProcessWeb problems.
If you are interested background material rather than the
detail of ProcessWeb and PML, there is the book
Business Information Systems, and
the IPG's Related Links page.
If you are interested in documentation on models, the appropriate
starting point is here. However, for many models you will
need to get hold of the relevant paper, project report or thesis.
Documents available include:
- ProcessWeb and PML:
Some Background for Developers is aimed at those writing models for
the first time. This has now been superceeded by
- CS637 Labbook which is used for the MSc students who use ProcessWeb
as part of the Process Modelling module.
This Labbook is available in PDF.
- The only tutorial type document that we have is Martyn Spink's PML Booklet,
which pre-dates ProcessWeb. This is still useful as an introduction
to the language, but you must remember all the user interface (UI) details are
no longer relevant.
- ProcessWeb - New Tower Framework overview and narrative introduction is for
those interested in the "new towers" which aim to give more flexible and
evolvable models, and promote greater sharing between models. (Get in touch
with Mark Greenwood if you want a copy)
The Related Documents section
provides a reasonable index into the various ProcessWeb publications.
(up to the end of 1999, when this was last updated)
Many of these are available via the IPG publications page.
- If you are looking for more information on HTML, the Department's
Web related links is a starting
point.
- ProcessWeb
Development Notes is currently (Sept 2001) being written. The Word -> HTML
conversion is not very good. The aim is to finally replace Ben's original
project report, with a more up to date description of how ProcessWeb
works.
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PML (Process Management Language)
ProcessWeb enacts process models witten in PML. This is a
high level process modelling and description language based on the concepts
of Roles and the Interactions which connect them. Roles
are active objects which contain data and may execute actions. Interactions
allow communication between two or more Roles, and are used to send messages
between Roles and to synchronise actions. Process models may be represented
by Role Activity Diagrams (RADs) which display the sequence of actions
within Roles, and the Interactions between them. The PEF insurance model
(see below) illustrates this.
Example
Role Activity Diagram (RAD)
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Using ProcessWeb
We currently operate the following ProcessWeb services, running
on the new Intel-based system. The Intel system appears to be working properly,
but please let us know if anything goes wrong. The services are described
below; to log in to a service, click on its link. You will need a user
ID to log into ProcessWeb. If you do not have one, you may
obtain a guest ID by going to a login page and clicking on the Guest
ID link.
You need a Netscape Navigator
(version 2 or later) or Microsoft Internet
Explorer (with Java activated) browser to use the system. You will
need to ensure that Cookies are accepted by your browser, and (unless
you are using the Server Push update mechanism with a Netscape browser)
that Java is enabled.
-
Demonstration
service This service is available for anyone who would like to try
it out. You may obtain a Guest User ID for this service by clicking on
the link and following the instructions on the login page.
We aim to make this service as stable as possible. We will only apply
new code when it is well tested or necessary for the system to function
correctly. We will move as many of the demonstration models as possible
onto this service.
Scheduled service interruptions: This service is stopped for
compaction and garbage collection at 0700 BSTevery
day (this takes approximately 20 minutes).
-
Development
service This service is used to test new developments (either new models,
or development work on the ProcessWeb system itself). It may be cleared
and rebuilt fairly frequently (this will cause all model instances and
guest users to be destroyed).
Scheduled service interruptions: This service is stopped for
compaction and garbage collection at 0200 BSTevery
day (this takes approximately 60 minutes).
-
We may provide additional services for particular groups of users, e.g. when running an MSc course
module using ProcessWeb, or for developing and testing.
Older versions of ProcessWeb are archived and may be restored
if required. We have not had to restore an older version since 1998,
and are no longer sure if we can remember what would need to be done.
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Creating and Using models
If you are logging in as a guest user, you will only be able to create
models via the library. This is a collection of pre-compiled models; you
may create a unique instance of any of these. Go to the library screen,
select the model you are interested in (see below for a list of models)
and enter a name to identify the new instance.
Once the model is created, the instance name will appear in the
model list on the browser screen. Select this model instance, and you will
be presented with a list of Roles within that model instance (if you are
not, try pressing the Show Unbound Roles and Show Roles bound
to Other Users buttons). Each Role will be in one of three states:
-
Bound to you
You own the Role, and may interact with it. You are offered two operations:
Connect, which opens the Role for interaction and Relinquish,
which changes the Role's state to Unbound. These Roles are always
displayed.
-
Bound to another user
These Roles are owned by other users. The system will show the owner
of the Role, and the Role may offer the View operation, which allows
you to see the Role as its owner does, but not to interact with it. These
Roles are only displayed if the Show Roles bound to Other Users
button has been pressed.
-
Unbound
Roles in this state are not owned by any user, and are not taking an
active part in the model. You may acquire ownership of such Roles by selecting
the Request Binding operation, which changes the Role's state to
Bound to you. Some Roles also offer the View operation (as
above). These Roles are only displayed if the Show Unbound Roles
button has been pressed.
Some models automatically bind Roles to the user who created the model
instance; others just create a set of unbound Roles which may be acquired
by any user. When you select the Connect operation on one of your
Roles, the ProcessWeb browser screen is replaced by the view
of that Role. You may return to the ProcessWeb browser screen
by clicking on the Return to Browser link on the top frame. When
you have finished using a particular model instance (e.g. the process has
completed or you are no longer interested in that model), please delete
the model instance using the Delete Model button on the browser
screen.
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Demonstrator models
NB. not all of these have been transferred to the new system. We
hope to make them all available in due course, and to add some more.
-
Scissors
-
This is a simple game for two players. When an instance of the model is
created, two unbound Roles are made available. On invoking the player Role,
each player is offered the same choice of stone, paper or scissors. An
algorithm in the process model determines who wins.
-
P2E
-
The Process for Process Evolution. This is a generic version of the process,
intended to allow people to add their own models.If you are located here
at the Computer Science Department, have a look in directory ~pwise/pwebModels/p2e.
-
Simple Banking
-
This is an implementation of P2E (Process for Process Evolution) used to
install and to evolve a simple banking process. Contact Ian
for details and running instructions.
-
CHIP
-
This is the largest demonstration model, implemented as part of a student
project. It models the assignment of Health Visitors to new-born babies
and the interactions between hospitals, health trusts, GPs and health visitors,
based on a case study of local NHS practices. It also incorporates links
to underlying Oracle databases, demonstrating the use of ProcessWeb
as a co-ordination technology.
-
PEF
Insurance
-
This model is designed to show the relationship between active models and
their representation using Role Activity Diagrams (RADs). The RADs are
used as the user interface to this model, which is based on the process
of assessing insurance proposals. This model interacts with an Oracle database.
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The original version of ProcessWeb was developed by Ben
Yeomans as part of the Systems Integration course. Ben worked under
the supervision of Prof.
Brian Warboys, and with the help of the Informatics
Process Group. The original project report, which is largely concerned
with the technical design of the system, is available here
in PostScript format. NB. Although the basic architecture described
in the report is still used, most of the details have now been changed.