標準封面

Foreword
Introduction    vi
1      Scope       1
2      Normative references    1
3      Terms, definitions, symbols and abbreviated terms      2
3.1   Terms and definitions     2
3.2   Symbols and abbreviated terms     7
4      Design considerations     9
4.1   Safety objectives in design     9
4.2   Strategy for risk reduction      11
4.2.1        General   11
4.2.2        Contribution to the risk reduction by the control system      11
4.3   Determination of required performance level (PLr)     13
4.4   Design of SRP/CS     14
4.5   Evaluation of the achieved performance level PL and relationship with SIL 15
4.5.1        Performance level PL     15
4.5.2        Mean time to dangerous failure of each channel (MTTFD)  16
4.5.3        Diagnostic coverage (DC)       17
4.5.4        Simplified procedure for estimating the quantifiable aspects of PL     17
4.5.5        Description of the output part of the SRP/CS by category     19
4.6   Software safety requirements        20
4.6.1        General   20
4.6.2        Safety-related embedded software (SRESW) 21
4.6.3        Safety-related application software (SRASW)        22
4.6.4        Software-based parameterization  24
4.7   Verification that achieved PL meets PLr        25
4.8   Ergonomic aspects of design  26
5      Safety functions      26
5.1   Specification of safety functions     26
5.2   Details of safety functions      28
5.2.1        Safety-related stop function   28
5.2.2        Manual reset function    29
5.2.3        Start/restart function      29
5.2.4        Local control function     30
5.2.5        Muting function      30
5.2.6        Response time        30
5.2.7        Safety–related parameters    30
5.2.8        Fluctuations, loss and restoration of power sources      30
6      Categories and their relation to MTTFD of each channel, DCavg and CCF   31
6.1   General   31
6.2   Specifications of categories    31
6.2.1        General   31
6.2.2        Designated architectures       32
6.2.3        Category B      32
6.2.4        Category 1      33
6.2.5        Category 2      34
6.2.6        Category 3      35
6.2.7        Category 4      36
6.3   Combination of SRP/CS to achieve overall PL        38
7      Fault consideration, fault exclusion        40
7.1   General   40
7.2   Fault consideration 40
7.3   Fault exclusion        40
8      Validation        40
9      Maintenance   40
10    Technical documentation       41
11    Information for use 41
Annex A (informative) Determination of required performance level (PLr) 43
Annex B (informative) Block method and safety-related block diagram      47
Annex C (informative) Calculating or evaluating MTTFD values for single components      49
Annex D (informative) Simplified method for estimating MTTFD for each channel    56
Annex E (informative) Estimates for diagnostic coverage (DC) for functions and modules 58
Annex F (informative) Estimates for common cause failure (CCF)       61
Annex G (informative) Systematic failure      63
Annex H (informative) Example of combination of several safety-related partsof the
control system        66
Annex I (informative) Examples     69
Annex J (informative) Software      76
Annex K (informative) Numerical representation of Figure 5       79
Bibliography    84