In this paper we describe an approach to the modelling of virtual enterprise agreements. An important and ever-present issue in the set-up phase of such a virtual enterprise is the virtual enterprise contract. As one of the goals of virtual enterprises is to become operational quickly, the time consumed by the set-up phase must be reduced to a minimum. At the same time it has to be guaranteed t...

Use of formal methods in verification activities for critical software development is a promising solution to increase the level of confidence compared to the current practice based on testing, for increasingly complex programs, at a lower cost than the current approach. Concretely, the upcoming standard DO-178C for software development in avionics gives credit to formal verification for suppor...

Optimistic contract signing protocols allow two parties to commit to a previously agreed upon contract, relying on a third party to abort or connrm the contract if needed. These protocols are relatively subtle, since there may be interactions between the subprotocols used for normal signing without the third party, aborting the protocol through the third party, or requesting connrmation from th...

In the last years, the concern with the correctness of programs has been leading programmers to enrich their programs with annotations following the principles of design-by-contract, in order to be able to guarantee their correct behaviour and to facilitate reuse of verified components without having to reconstruct proofs of correctness. In this paper we adapt the idea of specification-based sl...

This paper analyzes the use of alternative performance measures in an agency model in which contracting incorporates both formal and informal agreements. It is shown that under a proper use of verifiable and unverifiable performance measures, the two types of contracts are complements, regardless of the principal’s fallback position. The analysis therefore contrasts earlier results of the liter...

Consider the hypothetical situation of a society with virtually unconstrained storage and exchange of personal information and shameless exploitation thereof for decision making, for example in contract negotiation. In this paper we develop a stylised formal model to tackle the question if public knowledge about how exactly personal information is used in decision making changes aggregate behav...