A formal foundation for workflow composition, workflow view definition, and workflow normalization based on petri nets

摘要

In retail information systems it is common practice to subsume the data of products into product groups, which offers organizational advantages for example when new branches are opened, because they are assigned product groups instead of single products. Inspired by this approach, this paper focuses on business processes and proposes the usage of workflow modules stored in a workflow warehouse, which represent reusable, standardized components that are used to build more complex workflow models. In particular, the paper provides a formal foundation for such compositions in form of a workflow algebra based on Petri nets, which has similar operators known from relational algebra in databases. In addition, the need for a concept of workflow normalization is presented, which arises during the composition of workflow modules. Finally, it is shown how the algebra can also be applied in the context of Web service composition.