This special issue of IJEC is dedicated to two problem categories that have emerged in this area. The first problem category is how to encode con-tract conditions in deterministic language that can provide a basis for rea-soning about business contracts, static checking of contract clauses, and runtime monitoring of the actions of the parties as per the conditions stated in the contract. The second problem category is the development of soft-ware architecture that will support contract automation throughout the full life-cycle of a contract, including contract negotiation, validation, monitor-ing, and enforcing.

The papers in this special issue of IJEC provide various solutions to these problems with the aim of facilitating the sharing of business information, maintaining business relationships, and conducting business transactions in accordance with contracts.

Alberti et al. present an approach for specifying and verifying contracts using a computational logic-based language called the Social IFF-Proof Pro-cedure with Constraints (SCIFF). SCIFF is a declarative language based on abductive logic programming. First-class entities in SCIFF are events and expectations. Events represent actual behavior, such as actions taken by ac-tors, timeouts associated with deadlines, and sending messages or request-ing services. Expectations specify desired behavior in terms of events and logical expression over them called Integrity Constraints. Expectations are related to deontic operators, such as obligations, permissions, and prohibitions, which provide the building blocks of any business contract. The authors describe how SCIFF can be used for runtime verification of contracts and how an extension of SCIFF, called g-SCIFF (generative SCIFF), can be used for design-time verification. They also propose an encoding of the SCIFF contract rules in RuleML to support downstream software architectures for contract management.

The paper by Angelov and Grefen addresses the problem of identifying different activities and processes involved in a contract life-cycle. The au-thors propose that the contract life-cycle has four phases, namely informa-tion, pre-contracting, contracting, and enactment. Each of these phases in-volves various activities of parties involved in e-contracting, and the au-thors use speech-act theory to express such activities. For example, the en-actment phase requires such activities as monitor, send notifications, and react to notifications. This model supports seamless integration of cross-organizational and internal contract activities. The model can be also used to analyze existing contract processes as well as to support building an e-contracting system.

The paper by Bacarin et al. proposes a framework for better supporting automation of contracts in the context of agricultural supply chains. The authors introduce a model contract that is suitable for agricultural chains and can be instantiated to reflect specific requirements of the parties in-volved, including their supporting infrastructure, such as production, stor-age, and transportation. The paper explains key aspects of the negotiation process used in agreeing on specific contract instances, followed by discus-sion of several implementation issues, including how the negotiation can be implemented using Web services and different styles of negotiations that can be supported, such as actions and voting.

García and Gil first outline some of the limitations of current digital rights management (DRM) solutions and then address the issue of manag-ing copyright contracts over the Internet. The solution they propose builds from Semantic Web technology. The authors first propose a copyright on-tology, then analyze how to relate the notions introduced in the ontology and contract expressions provided by BCL (Business Contract Language). The copyright ontology is implemented in OWL-DL. This permits the use of OWL reasoners to monitor copyright contracts and report violations. The approach taken is illustrated by an example based on the so-called Tradi-tional Right and Usage.

The main aim of the paper by Rittgen is to show how it is possible to combine different techniques to engineering business network management based on contracts. The proposed framework is articulated in three phases: negotiation, simulation , and enactment. The negotiation phase defines the model of the relationships and interactions in the network, and it uses a combination of techniques (agent theory, Searle’s speech act theory, and an extension of DEMO—dynamic essential modeling of organization). In the second phase, the focus is on simulation of the processes to improve their performance and determine their parameters. Finally, the last phase con-siders how to generate workflows for modeling the interactions between participants to fulfill the business objectives of the network.

In summary, the papers in this issue illustrate the leading research in the field of contract architectures and languages. Many challenges remain, and new issues will emerge as the role of electronically supported business con-tracts becomes more prominent in cross-organizational business interac-tions. As this happens, it is increasingly important to understand the con-tractual issues associated with processes, policies, and people in cross-organizational IT systems, and to use the semantics of contracts to build flexible, adaptable, and evolvable cross-organizational systems.

We would like to point out that the work presented in this special issue is not isolated. The growing importance of the field becomes evident when one considers the efforts to provide languages and standards to represent contracts, policies, and other legal notions. These initiatives include OA-SIS’s LegalXML (www.legalxml.org), with the recently approved version 1.0 of the specification for eContracts (http://docs.oasis-open.org/legalxml-econtracts/CS01/legalxml-econtracts-specification-1.0.pdf); the OMG Semantic Business Rules Vocabulary (SBRV) (www.omg.org/cgi-bin/doc?dtc/2006-08-05), the European MetaLex (www.metalex.eu) and LKIF projects (www.estrellaproject.org/lkif-core), and the recently established W3C policy languages interest group (www.w3.org/Policy/pling).