F. Casati et al., WORKFLOW EVOLUTION, Data & knowledge engineering, 24(3), 1998, pp. 211-238
Citations number
14
Categorie Soggetti
Computer Science Artificial Intelligence","Computer Science Information Systems","Computer Science Artificial Intelligence","Computer Science Information Systems
A basic step towards flexibility in workflow systems is the consistent
and effective management of workflow evolution, i.e. of changing exis
ting workflows while they are operational. One of the most challenging
issue is the handling of running instances when their schemata are mo
dified: simple solutions can be devised, but they often imply losing a
ll the work done or failing in capturing the advantages offered by wor
kflow modifications; this is unacceptable for many applications. In th
is paper we address the problem of workflow evolution, from both a sta
tic and a dynamic point of view. We define a complete, minimal, and co
nsistent set of modification primitives that allow modifications of wo
rkflow schemata and we introduce a taxonomy of policies to manage evol
ution of running instances when the corresponding workflow schema is m
odified. Formal criteria are introduced, based on a simple workflow co
nceptual model, in order to determine which running instances can be t
ransparently migrated to the new version. A case study, relating the a
ssembling of a desktop computer, will exemplify the introduced concept
s.