To sustain a market for software components, component producers and consumers must agree on contracts. These contracts must specify each party’s obligations. To ensure that both sides meet their obligations, they must also agree on standards for monitoring contracts and assigning blame for contract violations. This dissertation explores these issues for contracts that specify the sequential be...

Code contracts is a way to attribute the programs with formal the specifications, based on which the verification of those programs can be performed. The focus on software verification is increasing and the mainstream languages start to adopt this technique. Scala is an object oriented and functional programming language that is very expressive and has a strong type system. Hence, developing a ...

We present a parametric calculus for contract-based computing in distributed systems. By abstracting from the actual contract language, our calculus generalises both the contracts-as-processes and contracts-as-formulae paradigms. The calculus features primitives for advertising contracts, for reaching agreements, and for querying the fulfilment of contracts. Coordination among principals happen...

Industry is currently pushing towards Service Oriented Architecture where code execution is not limited to the organisational borders but may extend outside of the organisation to which the sources are typically not accessible. In order to protect the interests of the organisation contracts are used which can be seen as a list of obligations, permissions and prohibitions. The composition of dif...

In the past decade, we have seen significant increase in the level of outsourcing in many industries. This increase in the level of outsourcing increases the importance of implementing effective contracts in supply chains. In this thesis, we study several issues in supply chain contracts. In the first part of the thesis, we study the impact of effort in a supply chain with multiple retailers. T...

Web services orchestrations and choreographies require establishing Quality of Service (QoS) contracts with the user. This is achieved by performing QoS composition, based on contracts established between the orchestration and the called Web services. Typical QoS parameters include maximum query throughput, response time, security, and validity of the response. Usually, QoS contracts are stated...

DESIGNING AND IMPLEMENTING A MODEL OF SYNCHRONIZATION CONTRACTS IN OBJECT-ORIENTED LANGUAGES By Karl Reimer Behrends This thesis describes the design and implementation of a synchronization mechanism, called the universe model, that is based on declaratively specified contractual relationships between client and supplier components. These synchronization contracts not only specify basic mutual ...

Standard incentive theory models provide a rich framework for studying informational problems but assume that contracts can be perfectly enforced. This paper studies the design of self-enforced relational contracts. I show that optimal contracts often can take a simple stationary form, but that self-enforcement restricts promised compensation and affects incentive provision. With hidden informa...

Inspired by facts from the private-sector construction industry, we develop a model that explains many stylized facts of procurement contracts. The buyer in our model incurs a cost of providing a comprehensive design and is faced with a tradeoff between providing incentives and reducing ex post transaction costs due to costly renegotiation. We show that cost-plus contracts are preferred to fixe...

Are contracts inherent in reusable libraries, or just one design technique among others? To help answer this question, we performed an empirical study of library classes from the .NET Collections library, which doesn’t use Design by ContractTM, to look for unexpressed contracts. This article reports on the buried contracts we have found, and discusses improvements to the architecture ─ especial...