Our paper “Learning Task Specific Web Services Compositions with Loops and Conditional Branches from Example Executions” was accepted to the IEEE Web Intelligence conference

The paper addresses a very intricate problem, which is learning complex web service compositions or workflows from a very small number of example executions that illustrate how to solve a particular problem. Most of the existing approaches to service composition employ techniques such as automated planning. Given some problem (goal) and a set of simple services, typically, some planning algorithm is used to find such composition of given services that solves the given problem. In our paper we take a very different approach. We assume that someone, for example a human expert, can present our system with a small number of example demonstrations that solve the given problem. Subsequently, we use these example demonstrations in our learning algorithm, and we learn a generalized workflow that solves the problem and that is still justified by the observed demonstration (execution trace). Importantly, in our approach we are able to learn generalized workflows that contain both repetitive executions (loops) and various branching, resulting e.g. from failures.

Learning Task Specific Web Services Compositions with Loops and Conditional Branches from Example Executions PDF
Harini Veeraraghavan and Roman Vaculín and Manuela Veloso. In 2010 IEEE / WIC / ACM International Conference on Web Intelligence, August 31 – September 3, pages 581–588. IEEE Computer Society, 2010. bibtex
@INPROCEEDINGS{Veeraraghavan-2010-WI,
author = {Harini Veeraraghavan and Roman Vacul\'{i}n and Manuela Veloso},
title = {Learning Task Specific Web Services Compositions with Loops and Conditional Branches from Example Executions},
booktitle = {2010 IEEE / WIC / ACM International Conference on Web Intelligence},
pages = {581--588},
month = {August 31 - September 3},
year = {2010},
publisher = {IEEE Computer Society},
pdf={http://www.vaculin.com/downloads/Veeraraghavan-Vaculin-WI-2010-final.pdf},
url={http://www.vaculin.com/downloads/Veeraraghavan-Vaculin-WI-2010-final.pdf},
timestamp = {2010.08.03}
}

ABSTRACT: Majority of the existing approaches to service composition, including the widely popular planning based techniques, are not able to automatically compose practical workflows that include complex repetitive behaviors (loops), taking into account possibility of failures and non-determinism of web service execution results. In this work, we present a learning based approach for composing task specific workflows. We present an approach for learning task specific web service compositions from a very small number of observations (one or more) of example service execution sequences (traces) that solve a given goal. The workflows learned by this approach generalize to the tasks justified by the observed execution trace. The generalization captures the repetitive executions of service sequences, conditional branching executions, and repetitions and branching resulting from failures. We evaluate the approach on a complex web services application involving arbitrary number of repetitive executions and failed executions.

Chapter “Process Mediation: Requirements, Experiences and Challenges” will appear in the book published by IGI Global

Our chapter providing an overview of our recent body of work primarily in area of process mediation will appear in the book “Electronic Business Interoperability: Concepts, Opportunities, and Challenges” published by IGI Global. Specifically, the chapter covers techniques for automated incompatibilities detection and resolution, service discovery in the process mediation context, techniques for monitoring, and techniques for fault handling and recovery.

Process mediation: Requirements, Experiences and Challenges PDF
Roman Vaculín and Roman Neruda and Katia Sycara. In Electronic Business Interoperability: Concepts, Opportunities, and Challenges, Ejub Kajan, Eds., IGI Global, 2010. (in print) bibtex
@INBOOK{Vaculin2010-EBI,
author = {Roman Vacul\'{i}n and Roman Neruda and Katia Sycara},
chapter = {Process mediation: Requirements, Experiences and Challenges},
title = {Process mediation: Requirements, Experiences and Challenges},
publisher = {IGI Global},
year = {2010},
editor = {Ejub Kajan},
pdf={http://www.vaculin.com/downloads/Vaculin-2010-EBI-chapter-final.pdf},
url={http://www.vaculin.com/downloads/Vaculin-2010-EBI-chapter-final.pdf},
booktitle = {Electronic Business Interoperability: Concepts, Opportunities, and Challenges}
}

ABSTRACT: In this chapter we address the problem of interoperability of incompatible business processes consisting of semantically annotated Web services. We propose a (semi-) automated solution, called process mediation, that analyzes the potentially incompatible process models of service requesters and service providers, identifies all incompatibilities, and automatically synthesizes reconciliation plans that can be used at runtime for resolving the identified incompatibilities. Compared to the previous research, the main novelty of our work is its strong focus on dynamic scenarios common for process-based service-oriented systems operating in open or semi-open dynamic environments. The chapter provides an overview of our recent body of work that covers techniques for automated incompatibilities detection and resolution, service discovery in the process mediation context, techniques for monitoring, and techniques for fault handling and recovery. We discuss the lessons we have learned and we also provide an outlook for future research directions.

Our paper “The process mediation framework for semantic web services” appeared in Int. J. Agent-Oriented Software Engineering

Our paper focused on process mediation of partially incompatible semantic web services process models has appeared in the International Journal on Agent-Oriented Software Engineering.

The process mediation framework for semantic web services PDF
Roman Vaculín and Roman Neruda and Katia Sycara. Int. J. Agent-Oriented Software Engineering, Vol. 3, No. 1, pages 27–58. 2009. bibtex

@ARTICLE{Vaculin-2009-IJAOSE,
author = {Roman Vacul{\'i}n and Roman Neruda and Katia Sycara},
title = {The process mediation framework for semantic web services},
journal = {Int. J. Agent-Oriented Software Engineering},
year = {2009},
volume = {3},
pages = {27--58},
number = {1},
pdf={http://www.vaculin.com/downloads/Vaculin-IJAOSE-09.pdf},
url={http://www.vaculin.com/downloads/Vaculin-IJAOSE-09.pdf},
timestamp = {2009.01.27}
}

Abstract

The ability to deal with the incompatibilities of service requesters and providers is a critical factor for achieving interoperability in dynamic open environments. We focus on the problem of process mediation of the semantically annotated process models of the service requester and service provider. We propose an Abstract Process Mediation Framework (APMF) identifying the key functional areas that need to be addressed by process mediation components. Next, we present algorithms for solving the process mediation problem in two scenarios: (1) when the mediation process has complete visibility of the process model of the service provider and service requester (complete visibility scenario) and (2) when the mediation process has visibility only of the process model of the service provider, but not the service requester (asymmetric scenario). The algorithms combine planning and semantic reasoning with the discovery of appropriate external services such as data mediators. Finally, the Process Mediation Agent (PMA) is introduced, which realises an execution infrastructure for runtime mediation.