Safety contract based design of software components

In this paper we discuss how to use a modified design methodology for contract based design (CBD) intended for development of software and component based systems by use of so called safety contracts. The primary purpose is to make a proposal on how to integrate safety contracts in a, for a tool, implementable way for automatic safety contract verification. This development technique is called safety contract based design (SCBD) in this paper. Focus is to discuss the similarities and differences between the actual contents in conventional CBD-contracts and safety contracts, and rules for how to verify agreements of safety contracts and how to ensure safety contract validity.