This paper presents the Visual Contract Language (VCL). VCL is a new visual language for abstract software specification at level of requirements. It is designed to be visual, formal and modular, and aims at expressing precisely structural and behavioural properties of software systems. VCL takes an approach to behavioral modelling based on design by contract that emphasises modularity.

The traditional realm of formal methods is the off-line verification of formal properties of hardware and software. In this paper we report a different approach that uses formal methods (namely the integration of automata modulo theory with decision procedures) on-the-fly, at the time an application is downloaded on a mobile application such as PDA or a smart phone. The idea behind security-by-...

In response to the problems that have arisen regarding the terminology and concepts of agent-oriented systems, previous work has described a formal framework for understanding agency and autonomy. In this paper we outline the framework and re ne it by adding further levels of detail to develop a formal model of the Contract Net Protocol. The model serves to make precise both the operations of n...

One of the principles of Design by Contract is that contracts for software components must be written in a declarative way, using a formal, mathematically founded notation. When we apply the Design by Contract methodology in a naive and straightforward way, we risk ending up with unwanted duplication. In this paper, we describe a methodology for writing class contracts that avoids specification...

Within IS outsourcing research there is an ongoing discussion whether formal contracts and relational norms function as substitutes or as complements to each other. However, even those deals which are based on relational norms usually comprise a contract as their foundation. We therefore aim at analyzing differences in contracting between both governance modes (i.e. contract-based or based on r...

This paper studies the incentive effects of a balanced scorecard within a multitask agency framework under both formal and relational contracts. First, the main characteristics of the balanced scorecard are analyzed with respect to performance measure congruity. It is shown that under complete verifiability, a properly designed balanced scorecard is capable of perfectly aligning the interests o...

Throughout modern business history, contract has been used as an organizational technology that holds counterparties in formal or legally binding agreements. The proliferation of contract prompted the emergence of professional contract managers who played an important but relatively peripheral role applying situational awareness to the practice of compliance and business relationship management...

The basic building blocks of Design by Contract are Boolean assertions, which are used to express preconditions, postconditions and invariants. For composed commands, i.e. for commands whose effect is realized using other commands, the expressiveness of such contracts appears to be insufficient. In this paper, we propose an extension of the Design by Contract methodology that enables us to expr...

In this work we present a visual model called CO Diagrams for the specification of e-contracts. This model includes specification of obligations, permissions, prohibitions, reparations and restrictions such as real time constraints. We also define a formal semantics of the visual model intended for the analysis and verification of the modeled contracts.

The paper proposes an approach to light-weight formal specification for interfaces, connectors, contracts and integration of component systems based on UML 2.0 superstructure. Both of static and dynamic contracts are provided with formal models. Dynamic contract can be verified through finding a legal environment in an optimistical way for the integrated components, whose contracts are depicted...