Автор: Alex
Дата: 25.11.08 16:38
Dear Andrew,
I understand that You know well the distinction between HAZOP (ref std IEC
61882 or various internal Companies practices) and SIL evaluation (IEC
61508/61511), but Your post may confuse colleagues approaching to these
issues :-).
So, some considerations in matter:
Normally HAZOP is performed in the design phase (preferably in phase of
basic engineering, but it never happens :-(). As usual, HAZOP study is a
prerogative properly of engineering firms, in collaboration with the
Customer.
Obviously, in case Owner decides to undertake HAZOP study of existing plant,
in order to verify/review safety issues, it may be held by the Owner. In any
case, the subject of HAZOP is entire technological process and relevant
equipment, not only C&I. Presence of experienced Process, Machinery,
Mechanical and Electrical specialists in the HAZOP team is absolutely
necessary.
One of the results of HAZOP is definition of target SIL. Analysis of SIL for
the correspondence to target is prerogative of C&I department. Other
specialists may be involved when necessary, but C&I dept carries out
responsibility of the results.
In consequence, there exist specialized SW packages for:
- HAZOP studies
- Reliability evaluation (SIL, FMEA etc.)
For now it is not clear to me, what type of SW our respectable colleague
gvozdik is going to distribute. In case it is SW for HAZOP studies, it may
be useful (as time-saving tool), but not strictly necessary. it's like to
have or not have Excel to perform financial calcs. You may use Excel or
simple electronic calculator; really important thing is to have the
knowledge of financial management. Probably, much more helpful tool should
be SW for the creation and simulation of process models, in order to verify
quickly various "what if" issues, but normally it is not used for HAZOP,
because there is no absolute warranty on the reliability of simulation
results.
In case SIL package is proposed, it should be important to verify if SW
package is proposed with the extensive database of instruments reliability
data. If not, this SW seems to be simple calculator, and similar tools may
be downloaded from sites of manufacturers of safety equipment, like HIMA.
Regards!
Alex
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