Amit K. Chopra

Amoeba: A methodology for modeling and evolving cross-organizational business processes

Business service engagements involve processes that extend across two or more autonomous organizations. Because of regulatory and competitive reasons, requirements for cross-organizational business processes often evolve in subtle ways. The changes may concern the business transactions supported by a process, the organizational structure of the parties participating in the process, or the contextual policies that apply to the process. Current business process modeling approaches handle such changes in an ad hoc manner, and lack a principled means for determining what needs to be changed and where. Cross-organizational settings exacerbate the shortcomings of traditional approaches because changes in one organization can potentially affect the workings of another. This article describes Amoeba, a methodology for business processes that is based on business protocols. Protocols capture the business meaning of interactions among autonomous parties via commitments. Amoeba includes guidelines for (1) specifying cross-organizational processes using business protocols, and (2) handling the evolution of requirements via a novel application of protocol composition. This article evaluates Amoeba using enhancements of a real-life business scenario of auto-insurance claim processing, and an aerospace case study.

Commitment-Based Service-Oriented Architecture

Existing service-oriented architectures are formulated in terms of low-level abstractions far removed from business services. In a new SOA, the components are business services and the connectors are patterns, modeled as commitments, that support key elements of service engagements.

Nonmonotonic Commitment Machines

Protocols for multiagent interaction need to be flexible because of the open and dynamic nature of multiagent systems. Such protocols cannot be modeled adequately via finite state machines (FSMs) as FSM representations lead to rigid protocols. We propose a commitment-based formalism called Nonmonotonic Commitment Machines (NCMs) for representing multiagent interaction protocols. In this approach, we give semantics to states and actions in a protocol in terms of commitments. Protocols represented as NCMs afford the agent flexibility in interactions with other agents. In particular, situations in protocols when nonmonotonic reasoning is required can be efficiently represented in NCMs.

Modeling and reasoning about service-oriented applications via goals and commitments

Service-oriented applications facilitate the exchange of business services among participants. Existing modeling approaches either apply at a lower of abstraction than required for such applications or fail to accommodate the autonomous and heterogeneous nature of the participants. We present a business-level conceptual model that addresses the above shortcomings. The model gives primacy to the participants in a service-oriented application. A key feature of the model is that it cleanly decouples the specification of an applications architecture from the specification of individual participants. We formalize the connection between the two--the reasoning that would help a participant decide if a specific application is suitable for his needs. We implement the reasoning in datalog and apply it to a case study involving car insurance.

Research directions in agent communication

Increasingly, software engineering involves open systems consisting of autonomous and heterogeneous participants or agents who carry out loosely coupled interactions. Accordingly, understanding and specifying communications among agents is a key concern. A focus on ways to formalize meaning distinguishes agent communication from traditional distributed computing: meaning provides a basis for flexible interactions and compliance checking. Over the years, a number of approaches have emerged with some essential and some irrelevant distinctions drawn among them. As agent abstractions gain increasing traction in the software engineering of open systems, it is important to resolve the irrelevant and highlight the essential distinctions, so that future research can be focused in the most productive directions. This article is an outcome of extensive discussions among agent communication researchers, aimed at taking stock of the field and at developing, criticizing, and refining their positions on specific approaches and future challenges. This article serves some important purposes, including identifying (1) points of broad consensus; (2) points where substantive differences remain; and (3) interesting directions of future work.

Producing compliant interactions: conformance, coverage, and interoperability

Agents in an open system interact with each other based on (typically, published) protocols. An agent may, however, deviate from the protocol because of its internal policies. Such deviations pose certain challenges: (1) the agent might no longer be conformant with the protocol—how do we determine if the agent is conformant? (2) the agent may no longer be able to interoperate with other agents—how do we determine if two agents are interoperable? (3) the agent may not be able to produce some protocol computations; in other words, it may not cover the protocol—how we determine if an agent covers a protocol? We formalize the notions of conformance, coverage and interoperability. A distinctive feature of our formalization is that the three are orthogonal to each other. Conformance and coverage are based on the semantics of runs (a run being a sequence of states), whereas interoperability among agents is based upon the traditional idea of blocking. We present a number of examples to comprehensively illustrate the orthogonality of conformance, coverage, and interoperability. Compliance is a property of an agents execution whereas conformance is a property of the agents design. In order to produce only compliant executions, first and foremost the agent must be conformant; second, it must also be able to interoperate with other agents.

OWL-P: a methodology for business process development

Business process modelling and enactment are notoriously complex, especially in open settings where the business partners are autonomous, requirements must be continually finessed, and exceptions frequently arise because of real-world or organizational problems. Traditional approaches, which attempt to capture processes as monolithic flows, have proved inadequate in addressing these challenges. We propose an agent-based approach for business process modelling and enactment which is centred around the concepts of commitment-based agent interaction protocols and policies. A (business) protocol is a modular, public specification of an interaction among different roles. Such protocols, when integrated with the internal business policies of the participants, yield concrete business processes. We show how this reusable, refinable and evolvable abstraction simplifies business process design and development.

Protocols for processes: programming in the large for open systems

The modeling and enactment of business processes is being recognized as key to modern information managment. The expansion of Web services has increased the attention given to processes, because processes are how services are composed and put to good use. However, current approaches are inadequate for flexibly modeling and enacting processes. These approaches take a logically centralized view of processes, treating a process as an implementation of a composed service. They provide low-level scripting languages to specify how a service may be implemented, rather than what interactions are expected from it. Consequently, existing approaches fail to adequately accommodate the essential properties of the business partners in a process (the partners would be realized via services)---their autonomy (freedom of action), heterogeneity (freedom of design), and dynamism (freedom of configuration).Flexibly represented protocols can provide a more natural basis for specifying processes. Protocols specify what rather than how; thus they naturally maximize the authonomy, heterogeneity, and dynamism of the interacting parties. We are developing an approach for modeling and enacting business processes based on protocols. This paper describes some elements of (1) a conceptual model of processes that will incorporate abstractions based on protocols, roles, and commitments; (2)the semantics or mathematical foundations underlying the conceptual model and mapping global views of processes to the local actions of the parties involved; (3) methodologies involving rule-based reasoning to specify processes in terms of compositions of protocols.

Toward verification of commitment protocols and their compositions

Commitment protocols have been proposed as a basis for modeling and enacting interactions among agents, such as those needed to carry out business processes. A central idea is that protocols would be developed and shared via libraries, and refined and composed to produce protocols that serve specific needs. Success in this program, therefore, presupposes that individual protocols and their compositions can be formally verified with respect to the properties of interest. This paper outlines an approach for verifying the correctness of commitment protocols and their compositions that exploits the well-known software engineering technique of model checking.

Engineering Foreign Exchange Processes via Commitment Protocols

Foreign exchange (FX) markets see a transaction volume of over