Modeling Business Entity State Centric Choreographies
Christian Huemer, Marco Zapletal
Institute of Software Technology
Vienna University of Technology
Favoritenstr. 9-11/188, 1040 Vienna, Austria
huemer@big.tuwien.ac.at, marco@ec.tuwien.ac.at
Philipp Liegl, Rainer Schuster
Austrian Research Centers GmbH - ARC
Research Studios Austria
Thurngasse 8/20, 1090 Vienna, Austria
{pliegl, rschuster}@researchstudio.at
Abstract
In a B2B environment business partners interact with
each other by exchanging electronic business documents.
The agreements and commitments between the partner re-
quire a certain order in the flow of business documents. This
flow - commonly known as choreography - often depends on
the actual content of a business document. E.g. the next step
depends on whether a price was stated in a quote document
or not in the step before. These characteristics usually affect
the states of a business entity - whether a quote is in state
provided or in state refused. The states of a business entity
usually define the next steps in the choreography of a collab-
orative business process. Thus, it is important that the ac-
tual business document content and resulting business entity
states are unambiguously defined in a global choreography.
In this paper we show how the modeling of business en-
tity state centric choreographies may be incorporated into
UN/CEFACT’s modeling methodology (UMM) - one of the
best known approaches to model global choreographies.
1. Introduction
Exchanging business documents between business part-
ners is not particularly new. It has been implemented for
a long time by the concepts of Electronic Data Interchange
(EDI) [4]. EDI standards like UN/EDIFACT and ANSI X12
standardized the business document types. Different docu-
ment types are exchanged in an agreed order to implement a
business case electronically. Usually, business partners sign
a trading partner agreement in order to establish an elec-
tronic partnership. This trading partner agreement covers
the definition of a subset of the EDI document standards
and the flow of business documents in addition to the legal
terms of the partnership. In absence of a formal description
for the document flow in EDI standards, the agreed order of
the document types is described in plain text.
Later on XML-based business document standards pro-
vided an alternative to traditional EDI standards. An
overview of XML business document standards is provided
by Li [13]. These standards are also limited to the format of
the business documents and do not consider the document
flow. However, XML also led to more advanced technolo-
gies like Web Services and ebXML that may be used to ex-
change business documents of a certain (XML-based) busi-
ness document standard. Both, Web Services and ebXML
include specifications for describing the flow of business
documents, e.g. BPEL [1], WS-CDL [22], ebXML BPSS
[20].
The flow of documents may be described from the per-
spective of a participating partner or from a neutral perspec-
tive. In the first case we talk about a local choreography and
in the second case of a global choreography. BPEL may be
used to describe a local choreography, whereas WS-CDL
and ebXML BPSS capture a global choreography. A global
choreography is usually used to define a contractual agree-
ment on the document flow between the business partners.
In contrary, a local choreography specifies the flow of docu-
ments as expected at the interface of the a business partner’s
information system. This means that if a buyer and a seller
want to collaborate they agree on a single global choreogra-
phy and each one derives its own local choreography as an
interface to its own information system.
In this paper we concentrate on global choreographies.
We prefer a graphical modeling language to specify a global
choreography. A visual representation of the agreed docu-
ment flow enables a better understanding and verification by
the business partners. Furthermore, modeling languages are
able to abstract from the IT-platform - such asWeb Services,
ebXML and what ever comes up in the future - in order
to survive technological changes. Modeling of choreogra-
phies is based on three main concepts according to Dubray
[2]: event, activity and state. Furthermore, he analyzes that
most approaches have focused on events (pi-calculus) or ac-
tivities (petri nets, activity diagrams), but hardly any have
focused on states, in particular business entity states.
In this paper we demonstrate the importance of business