This part of BS 5760 provides a description of the principles of
the dependability case and provides guidance on its content and
application in systems engineering. The dependability case can be
used throughout the life cycle, from concept and definition, through
design and development; manufacture and installation, to operations
and maintenance; mid?life enhancement, and eventual disposal.
Whilst this part of BS 5760 is primarily intended for application by
the system developers, it will be of value to bodies who might be
contracted to manage the dependability case for a project, where
deemed necessary.
This part of BS 5760 has five main clauses which describe:
a) principles of the dependability case (Clause 5);
b) development of the dependability case (Clause 6);
c) providing the evidence (Clause 7);
d) presenting the evidence (Clause 8);
e) assessing the adequacy of the evidence (Clause 9).
The activities required for the achievement of dependability depend
on the nature and development state of the system and are likely to
vary significantly from one project to another. The guidelines are not
to be considered as being prescriptive in nature: they are generic and
do not attempt to be exhaustive.
Annex A describes the general requirements for the dependability
case and dependability case report
Annex B provides examples of dependability management risks at
different stages of a system’s life cycle.
Annex C provides a checklist of points for assessing the adequacy of
evidence. The checklist is not to be considered to be prescriptive or
exhaustive; it is generic and provides guidance to supplement the
generic guidance provided in Clause 8.
Annex D describes the dependability risk reduction process shown in
Figure 7 using illustrative examples where appropriate.
Annex E describes the dependability evidence framework, expanding
on the information given in 5.1.
Whilst this part of BS 5760 does not specifically address safety cases,
the same principles can be applied.