RAMS[10] 設計手法

設計手法はSIレベルによって異なるって書きました。例えば、IEC 62425 では、

Table E.1 – Safety planning and quality assurance activities では以下のようになっています。

1 ChecklistsR: checklist of activities and items to be
同左R: checklist of activities and items to
be produced
2 Audit of tasksRRHRHR
3 Inspection of issues of documentationHR: documents agreed between
railway/safety authority and industry
同左HR: all documents同左
Review after change in the safety planHRHRHRHR
Review of the safety plan after each safety life-cycle phaseHRHRHRHR
Table E.1 – Safety planning and quality assurance activities

Table E.2 – System requirements specificationでは以下のようになっています。

Techniques/Measures SIL1 SIL2 SIL3 SIL4
1 Separation of safety related
systems from non
safety-related systems
R: well defined interfaces between safety related
systems and non safety-related
systems (SRS)
同左HR: well defined interfaces between
safety-related systems and non
safety-related systems (SRS) and
interface analysis
2 Graphical description
including for example block
3 Structured specificationHR: manual hierarchical separation into
subtasks, description of the interfaces
同左HR: hierarchical separation using
form alised methods, automatic
consistency checks, refinement
down to functional level
4 Formal or semiformal
R: computer-aided
R: computer-aided
5 Computer aided
specification tools
R: tools without
preference for one
particular design
R: model oriented procedures with
hierarchical subdivision, description
of all objects and their relationship,
common data base, automatic
consistency check
6 ChecklistsR: prepared checklists for all safety lifecycle
phases, concentration on the
main safety issues
同左R: prepared detailed checklists for all
safety life-cycle phases
7 Hazard logHR: Hazard log to be established and maintained throughout the system life-cycle同左同左同左
8 Inspection of the
Table E.2 – System requirements specification

他にもたくさんありますが、このようにSIレベルで要求が変わるということを理解してください。これは、IEC 62278 62279でも同じです。