This volume contains the papers presented at REFINE 2018: Refinement Workshop held on July 18, 2018 in Oxford.

There were 6 submissions. Each submission was reviewed by at least 3, program committee members. The committee decided to accept 6 papers. The program also includes 2 invited talks.

RefineNet was an EPSRC-funded network in the area of refinement of formal specifications (2004-2007), and is now a special interest group of BCS-FACS.

Work on the foundations of languages such as Z, B, VDM and CSP have led to their widespread use in certain industrial sectors, e.g., those with security or safety critical concerns. In addition to precise specification, formal methods also allow the possibility of precise and verifiable development, as captured by the concept of refinement.

Refinement is one of the cornerstones of a formal approach to software engineering. Refinement is the process of developing a more detailed design or implementation from an abstract specification through a sequence of mathematically-based steps that maintain correctness with respect to the original specification.

Work on refinement in the late 80s made initial progress in a number of areas, however recently new aspects of the subject have been explored. This has been inspired by a number of factors including new applications, industrial case studies, integration of notations and the need for proper tool support. The subject has therefore moved from initial work conducted in individual notations to a more wide ranging focus.

The purpose of RefineNet was to bring together people who are interested in the development of concrete designs or executable programs from formal specifications, tool support for formal software development, and those who have practical experience with formal refinement methodologies.

The REFINE workshop organisers wish to thank all FLoC organisers and volunteers.