Formalizing Higher-Order Mobile Embedded Business Processes with Binding Bigraphs

Abstract

We propose and formalize HomeBPEL, a higher-order WS-BPEL-like business process execution language where processes are firstclass values that can be stored in variables, passed as messages, and activated as embedded sub-instances. A sub-instance is similar to a WS-BPEL scope, except that it can be dynamically frozen and stored as a process in a variable, and then subsequently be thawed when reactivated as a sub-instance. We motivate HomeBPEL by an example of pervasive health care where treatment guidelines are dynamically deployed as sub processes that may be delegated dynamically to other workflow engines and in particular stay available for disconnected operation on mobile devices. We provide a formal semantics based on binding bigraphical reactive systems implemented in the BPL Tool as part of the Bigraphical Programming Languages project at ITU. The semantics is an extension of a semantics given previously for a simplified subset of WS-BPEL and exploits the close correspondence between bigraphs and XML to provide a formalized run-time format very close to standard WS-BPEL syntax, which also constitutes the representation of frozen sub-instances.

Notice of Retraction: Modeling Service Interactions in Term of Bigraphs

“…Bigraphs and bigraphical reactive systems (BRSs) are novel theoretical tools that consider locality and connectivity [3][4] [7], and they have been applied in business process management [5] [6]. This paper provides representations of service interaction patterns based on bigraphs for CCS [7], and it has two purposes.…”

Computing Embeddings of Directed Bigraphs

“…The flux network reflects the linking structure and contains an edge connecting each point to its handle; these edges have an integer capacity limited to 1 and are represented by the variables defined in (4). The remaining edges of the network are organised in two complete biparted graphs: one between guest and host handles and one between guest and host points.…”

“…The dynamics of a system is defined by means of a set of graph rewriting rules, which can replace and change components' positions and connections. BRSs have been successfully applied to the formalization of a wide spectrum of domain-specific models, including context-aware systems, web-service orchestration languages [4,5,20,28]. BRSs are appealing because they provide a range of general results and tools, which can be readily instantiated with the specific model under scrutiny: libraries for bigraph manipulation (e.g., DBtk [1] and jLibBig [23,24]), simulation tools [10,19,21], graphical editors [9], model checkers [27], modular composition [26], stochastic extensions [18], etc.…”

Towards a formal model for composable container systems

“…For this reason, this formalism is a prefect candidate for closing the gap between abstract models for formal methods and tools, and concrete graphical languages for system designers and developers. Indeed, BRSs have been successfully applied to the formalization of a broad variety of domain-specific models, including context-aware systems and web-service orchestration languages; a non exhaustive list is [1,5,7,11,13,20,24,25]. Beside their normative power, BRSs are appealing because they provide a range of general results and tools, which can be readily instantiated with the specific model under scrutiny: libraries for bigraph manipulation (e.g., [2] and jLib-Big [16,17]), simulation tools [12,14], graphical editors [8], model checkers [23], modular composition [22], etc.…”