Hi-Tec - by how much?

Some product advertisements mention about manufacturing through computer based technology. Some bill boards for spectacle shops mention about computerized checkups and tests.Some new plants are known as hi-tech facilities.
In all these, what we understand is that they use some software or some techniques that run on computers. However, unless rigorous checks are not made to the software before its use, hi-tec can lead to complex problems, which we can't understand. For this, the programmer should understand fully the requirement, which should be specified by the engaging agency in clear terms. If there is no clarity in specifications and the understanding of the same by programmer is not checked, glitches may come later, which may develop in to unimaginable proportions.
What we start with hi-tec, also can become low-tec after sometime, when changes are made but not tested fully.
Management of change, i.e checking the modifications in an existing procedure for achieving the desired output, if not done properly can manage us later.
Some plant facilities started on PLC based operations initially will be suspended and reverted to manual mode because of the glitches. This is because of lack of clarity in what we want, what we conveyed to the developers/suppliers, and what we got. Hardware problems also can lead to similar situation. Sometimes, because of the complex operations involved in operating PLC based plants and poor training, managers revert to manual operations.
If we are overconfident that nothing will happen because a plant is hi-tec and leave the caution to the air, then also we may find surprises.
Hi-tec will be safe only when we address above issues.