Catalogs > Safety Products Catalog > Principles, Standards and Implementation > System Design According to ISO/EN 13849 and SISTEMA
System Design According to ISO/EN 13849 and SISTEMA
| SISTEMA Software PL Calculation Tool |  |
System Structure | |
Reliability Data | |
Methods of Data Determination | |
Diagnostic Coverage | |
Common-Cause Failure | |
Mission Time | |
| Systematic Faults | |
Fault Exclusion | |
Performance Level (PL) | |
Subsystem Design and Combinations | |
Validation | |
Machine Commissioning | |
Mission time represents the maximum period of time for which a subsystem (or system) can be used. After this time, it must be replaced. Mission time must be declared by the manufacturer of the components. Mission time will usually be the same as the “proof test interval” or “lifetime” (whichever is the smaller) as used in IEC/EN62061. The safety system designer must then consider the mission time of the components to determine the mission time of each safety function. For mechanistic components the T10d value gives this usable lifetime value in terms of the number of operations. The T10d value is derived as part of the B10d calculation.