Page 18 - Cyber Warnings

The reasons to catastrophical events within a critical

infrastructure

By Milica D. Djekic

Many would believe that the reasons to catastrophical events within any industrial infrastructure
could be based on skillfully prepared hacker’s attacks. Basically, that’s the case with some of
scenarios and in any case you would need the good investigation and deep forensic work. On
the other hand, we would suggest that if any catastrophical event occurs within an industry –
you should not rush with a conclusion and speculate about some hacker’s or terrorist attacks.
Why? So often – the reason to the entire industrial system’s crash would not be any sort of
cyber incidents, but rather unskillfully designed control system to that plant. The fact is that if
you do not have any sort of smartly designed fusing circuitry within your control system which
would simply switch off the entire plant if the physical variables go too high – you would get an
accident. Right here, we would try to discuss how to prevent such an occurrence applying the
smart control system design.

CASE 1: The poorly designed control system

As we said – the reason to some catastrophical event happening within a critical infrastructure
could be poorly developed control system to that plant. For instance, many designers would use
only ON – OFF control without applying any feedback circuit with their design. If you use only an
open loop system – you would miss to collect the information about the physical variables being
present at your output and compare them with the desired values being set at the input. In other
words, your control system would not necessarily operate accurately and you would miss to
know its state at the output. For such a reason, we would suggest to control system designers
to use the feedback control which would offer them much secured operation of their plants.
Also, if you use the feedback system – you would realize that you would always get the
feedback information about the situation with your plant and you would know exactly if the
stability of your system got threatened. For instance, at the output you could get a plant which
parameters would be dependable from temperature, pressure, liquid concentration and so on,
so you would need to estimate which level of those parameters got allowed. In case any of
these variables went too high overcoming the allowed values – your system should react
smartly trying to switch off such a design and offer an opportunity to those parameters to go
down. So, if you want to design a good control system to your plant – you need to use some
sensing and measurement equipment in your feedback branch and also apply some fusing
circuitry which would offer you to switch off your industrial system before it gets so unstable and
possible dangerous to some catastrophical accidents even happen.

CASE 2: The inappropriate maintainace of a system
This case would suggest that some of the staffs working to the industrial asset would not obtain
their tasks properly. For instance, the authorized staff doing the maintainace of the industrial
18 Cyber Warnings E-Magazine December 2016 Edition
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