A node-centric analysis of metagraphs and its applications to workflow models

Business processes and its related workflow systems have received greater interest in practice and research in the last decade. Many analytical methodologies for analysis and design of workflow systems emerged. A recent formal approach to study workflows using a graph-theoretic method called `metagraphs' has demonstrated effectiveness for analysing connectivity and interactions of information and resources between workflow components. However, past works in analysis of metagraph are element-based. Since nodes in metagraphs represent either the input or output of an activity it is natural to process information contained in a node taken as a unit. This paper takes a node-centric view on metagraphs that is a major departure from the element-based approach today. The change in focus requires provisioning an analysis framework under the node-centric views. New basic constructs including, but not limited to, concepts such as: 'surplus sets', 'deficit sets', 'state of a path', and 'node-centric view of adjacency matrices' are introduced. The approach produces computational feasible systems for elements that are over supplied and/or under supplied from a source node to a target node of any path of the metagraph. Such information could be valuable for designing workflow systems. Also, the node-centric approach is shown to be an extension of the basic constructs of element-view metagraphs and is a complementary method for validating information requirements of workflow modelling. Illustrative examples are given.