Institute of Measurement and Control. Functional Safety 2016
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Example of techniques and measures to be found in IEC 61508 part 2 Annex A & B which form part of
typical SIS and which can be leveraged by systems integrators and end users (reference to relevant
detailed description in 61508 is shown in brackets) :-
1. Make things easy to understand, Keep it simple.
2. Use an object orientated modular approach (A2.7, A4.4, B3.4)
3. Design higher level function blocks, thoroughly test and re-use as much as possible.
(A2.8, A4.7, B3.3)
4. Build up libraries and re-use tested code (A2.8, A4.7)
5. Ensure SIF can be easily identified amidst other convenience functions (B1.3)
6. Make use of peer reviews, independent code reviews. (A9.3)
7. Consider use of higher level Safety Lifecycle Tools as an alternative to conventional
application programming (A2.11D)
8. Use of design and coding standards (A.4) Use checklists (A10.1, B2.5)
Figure 4 Example Safety Lifecycle Tool
But what might the future hold?
More than half of UKCS offshore installations are now operating beyond their original design life and
the management of older SIS, perhaps installed prior to the release of IEC 61508, can undoubtedly
provide a tough functional safety challenge.
Against this backdrop it may seem inappropriate to focus too much on the technology of the future but
Operating companies are constantly being driven to seek productivity gains in order to offset lower
revenues. One approach of increasing interest in terms of increased productivity is that of learning the
lessons from other sectors. One particular hot topic is that of digitalisation.
Digitalisation and Functional Safety
We are widely thought to be on entering into a new Industrial revolution. The first such revolution was
the mechanization of production using water and steam power. The second then introduced mass
production with the help of electric power. The third involved the use of electronics and IT to further
automate production. And now the fourth revolution, which is already underway, is digitalisation and
the transition to the “digital enterprise”.