xoEPC - Jan Mendling

2 1. Introduction
Dav93, JB96, Sch98a, ACD + 99, Sch00, LR00, ADO00, AH02, MCH03, BKR03, Kha04,
LM04, Hav05, SF06, Sta06, Jes06, SCJ06, WLPS06, KRM06, Smi07]) as well as in-
ternational professional and academic conference series, such as the BPM conference
[AHW03, DPW04, ABCC05, DFS06], confirm the importance of BPM. Despite the
overall recognition of its importance, several fundamental problems remain unsolved by
current approaches.
A particular problem in this context is the lack of research regarding what is to be
considered good design. The few contributions in this area reveal an incomplete under-
standing of quality aspects in this regard. Business process modeling as a sub-discipline
of BPM faces a particular problem. Often, modelers who have little background in formal
methods, design models without understanding the full implications of their specification
(see e.g. [PH07]). As a consequence, process models designed on a business level can
hardly be reused on an execution level since they often suffer from formal errors, such
as deadlocks. 1 Since the costs of errors increase exponentially over the development life
cycle [Moo05], it is of paramount importance to discover errors as early as possible. A
large amount of work has been conducted to try to cure the symptoms of this weak un-
derstanding by providing formal verification techniques, simulation tools, and animation
concepts. Still, several of these approaches cannot be applied since the business process
modeling language in use is not specified appropriately. Furthermore, this stream of re-
search does not get to the root of the problem. As long as we do not understand why
people introduce errors in a process model, we will hardly be able to improve the design
process. There is some evidence on error rates for one particular collection of business
process models from practice [MMN + 06b, MMN + 06c]. 2 We will take this research as a
starting point to contribute to a deeper understanding of errors in business process mod-
els.
1 In the subsequent chapters, we will distinguish between two major types of errors. Firstly, formal
errors can be identified algorithmically with verification techniques. Secondly, inconsistencies between the
real-world business process and the process model can only be detected by talking to stakeholders. The
focus of this thesis will be on formal errors.
2 Classroom experiences are reported, for example, in [MSBS02, Car06].