MechChem Africa April 2017

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April 2017 • MechChem Africa ¦ 33
⎪ Minerals processing, metallurgy and materials ⎪
The characteristics of environmental
factors
The degree to which factors are few in number
and similar to one another.
The degree to which
factors remain stable
or are in a continual
process of change.
Simple Complex
Static Low Moderately low
Dynamic Moderately high High
The extent of perceived uncertainty affecting
decisions.
Figure 3: Perceived uncertainty compared to decision environment characteristics.
world is a far from simple place. Operational
circumstances, economic, political and cul-
tural systems that affect outcomes are highly
complex. They have a myriad of interacting
variables. The relationships between those
variables are shifting constantly. For any de-
cision there are normally between four and
seven significant variables. These need to be
identified,thencontrolled,influencedorsimply
monitored (in the case of exchange rates, for
example).
The perceived uncertainly associated with
decision environment characteristics is shown
in Figure 3. The significant operating circum-
stances govern the decision environment
and these may or may not be static and time
dependent. A balance within the context of
the significant variables enables reasonableas-
sessment andunderstandingof associated risk.
Conclusions
The first thing to take from this article is that
nobodyknows exactlyhowamaterial or design
will react over time. Sure, there will be lots of
people making guesses. It is even certain that
some of those guesses will turn out to be right.
Anewguruwill beborn,whowill havehisor her
time in the sununtil their nextmajor prediction
fails miserably. It has always been so.
The second thing to take away from this
article is that there is often no need to make
absolute predictions at all. Engineers all need
the skill to identify the full set of predicted
operating conditions that affect choices, com-
binedwith the ability toworkout a strategy for
when the situation changes.
The engineering concern is not to predict
with certainly but to recognise fairly soon if
significantchangeshaveoccurred.Astrategyfor
deviations is required. An example of this is the
food and beverage sector, which made invest-
mentdecisionsinthe1980sbasedonfunctional
compliance. In the early 2000s new legislation
related to health has emerged alongside the
sustainability criteria. This limits acceptable
bacteria and spore counts in the final product.
Bacteria are directly associated with the build-
up of bio films on product contact surfaces.
Whilst the focus had always been struc-
tural integrity, the hygienic welding of joints
introduced new challenges. These hygiene
requirements, which provemore demanding
to achieve than structural integrity, are in
addition to other operational requirements.
The approach to engineering choices
Sanitary piping is stainless steel high purity tubing
for biopharmaceutical, food and beverage facilities.
Whilst the focus had always been structural
integrity, the issue of hygienic joints introduced new
fabrication challenges to allow the systems to be
cleanable and eliminate bacterial entrapment areas.
shouldworkwell. It has in thepast. It requires
understanding by client bodies. It is neither
fun nor simple. If you want simple answers
to complex circumstances, take some of your
moneydown to the casino. Infrastructure en-
gineering is not theplace togambleon simple
answers, evenwhen the questions posed are
simple to express. q