In distributed real-time applications where data needs to be
shared among distributed components it is desirable to have
overall data consistency at all times. This is crucial for
safety-critical systems, where inconsistency can lead to
catastrophic failures. Overall continuous data consistency is,
however, rarely possible to achieve. For distributed systems, a
relaxed view based on the temporal validity of data can be proven
sufficient. If components in a distributed system have different
temporal validity constraints for the same data, then as long as
these constraints are satisfied overall system inconsistency is
not harmful. We propose the use of a formal analysis technique for
guaranteeing temporal validity of shared data. The approach
consists in expressing temporal validity constraints on data in
design using an extension of UML's Object Constraint Language
(OCL). Further we can translate these OCL constraints into logical
formulae. The logic is a real-time temporal logic of knowledge
suitable for verification through model checking. It allows us to
check that the shared data in the system is consistent ``enough''
and cannot be a source of failure. We therefore believe that our
approach is a valuable addition to hazard analysis and
hazard-control measures during early stages of software
development. We illustrate the approach with an open dynamic
real-time distributed system.