A Tolerant Approach to Faults

Abstract

The work on recovery blocks springs from the basic realism of recognising that in practice ‘correctness’ may be an unattainable ideal in software development. The work captures and embodies insights of wide applicability. As the authors of the work recognised, these insights can also be extended to the development of complex software-intensive systems where the faults—or, more generally, exceptional conditions—to be handled have their origins in the problem world outside the software. By generalising the notion of a ‘block’ to include processes and non-terminating behaviours, the same insights can be deployed in structuring the general functional behaviour of the system.