Verifying sequence and content for safety critical hypermedia systems

There is an increasing interest in the use of hypermedia for technical documentation systems. Where these systems are used in safety critical industries the design quality of the hypermedia product is of primary importance, since errors in presentation can cause errors in maintenance procedures, which in turn can cause malfunction of safety critical equipment. For this reason it is necessary to develop rigorous design methods which can offer guarantees of correctness. This paper extends previous work on this topic. The earlier work discussed a technique which allowed designers' storyboards to be translated into a process algebra specification-'formal storyboards'-allowing safety properties concerning sequence of presentation to be demonstrated. This technique was not applicable to the content of the presentation. This paper shows how the method may be combined with state based formal methods to provide a means of formal verification of the content as well.