Adaptable Pervasive Flows (APFs) is a novel  novel workflow-based paradigm for the design and execution of pervasive applications, where dynamic workflows situated in the real world are able to modify their execution in order to adapt to changes in their environment.  More precisely, Adaptable Pervasive Flows (APFs) [4] are proposed as an extension of traditional workflow concepts [3] in order to make them more flexible with respect to their pervasive execution environment. APFs are dynamic workflows situated in the real world that modify their execution in order to adapt to changes in their environment. This requires on the one hand that a flow must be context-aware: during execution it must be possible to obtain information on the underlying environment (e.g. relevant information on world entities, status of other flows, human activities). On the other hand flow models must be flexible enough to allow an easy and continuous adaptation. APFs are based on WS-BPEL a well-known language for specifying flows in a Web Service setting, and extend it in order to implement all the aspects related to pervasive applications.

APFoL is a formal language for adaptable pervasive flows [1]. Amongst the various formal approaches to flow languages we have chosen Blite [2] as a starting point. Blite is a process calculus that captures a significant part of the WS-BPEL language. We build our language as an almost straightforward extension of Blite. More precisely, we equip the language with abbreviations to deal with adaptation mechanisms, flow constructs and activity types typical of adaptable pervasive flows. The formal language proposed permit us to formally specify the built-in adaptation constructs informally proposed in [3].

[Download] BPEL Code
[Download] APFoL Code


Related Pubblications

[1] A. Bucchiarone, A. Lluch Lafuente, A. Marconi and M. Pistore. A formalisation of Adaptable Pervasive Flows.
Accepted to the 6th International Workshop of Web Services and Formal Methods (WSFM'09), September 4-5, 2009, Bologna, Italy.

[2] A. Lapadula, R. ugliese, and F. Tiezzi. A formal account of ws-bpel.
In D. Lea and G. Zavattaro, editors, COORDINATION, volume 5052 of Lecture Notes in Computer Science, pages 199–215. Springer, 2008.

[3]  A. Marconi, M. Pistore, A. Sirbu, H. Heberle, F. Leymann, and T. Unger. Enabling Adaptation of Pervasive Flows: Built-in Contextual Adaptation. SOA Technical Report, June 2009.

[4] K. Herrmann, K. Rothermel, G. Kortuem, and N. Dulay. Adaptable Pervasive Flows - An Emerging Technology for Pervasive Adaptation. In Workshop on Pervasive Adaptation (PerAda), September 2008.