RAMS[10] 設計手法

2021年10月1日 2021年10月11日

mack0113

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。

Techniques/Measures	SIL1	SIL2	SIL3	SIL4
1 Checklists	R: checklist of activities and items to be produced	同左	R: checklist of activities and items to be produced	同左
2 Audit of tasks	R	R	HR	HR
3 Inspection of issues of documentation	HR: documents agreed between railway/safety authority and industry	同左	HR: all documents	同左
Review after change in the safety plan	HR	HR	HR	HR
Review of the safety plan after each safety life-cycle phase	HR	HR	HR	HR

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	同左
2 Graphical description including for example block diagrams	HR	HR	HR	HR
3 Structured specification	HR: 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	同左
4 Formal or semiformal methods	ー	ー	R: computer-aided	R: computer-aided
5 Computer aided specification tools	ー	R: tools without preference for one particular design method	R: model oriented procedures with hierarchical subdivision, description of all objects and their relationship, common data base, automatic consistency check	同左
6 Checklists	R: 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	同左
7 Hazard log	HR: Hazard log to be established and maintained throughout the system life-cycle	同左	同左	同左
8 Inspection of the specification	R	R	HR	HR