A regular client of mine was a value-added-reseller of computing
and communications equipment. They installed bar code and computing
equipment into mature manufacturing plants, such as paper mills,
steel mills, etc. One such plant was experiencing problems with the
results of the bar code scans, and I was called in to look at the
situation. After meeting with the plant personnel, examining their
data, and touring the facility, it became obvious they were
experiencing data errors between the bar code readers and the
central computer.
I considered performing a quantitative test with some
communications monitoring equipment, but first I looked at the
specifications for the cable they had installed for the
communications links. In fact, the cable vendor had recommended the
least expensive cable; it was not even shielded. I specified one of
the top of the line cables, one with double-shielded twisted pairs,
and recommended they replace the cable in the worst communication
link. The took my advice and the errors disappeared. They quickly
replaced all of the cable in their plant communication links.
This a good example of misinformed good intentions doing more
damage than good. The least expensive cable would appear to save the
client money, but the most-expensive cable was by far the most
cost-effective solution.
