Information Technology Reference
In-Depth Information
time - had the purchase order system still on their computer. Well,
had
is the operative
word because one of my co-workers deleted it there. He didn't do a backup first but
simply eradicated it. As you can guess, that wasn't very intelligent.
By this time I had left the company but was contacted about the fiasco at home. I
mentioned that on the desk where I spent my days at the office was a tape with the
purchase order system. Restoring it meant that the client would have to start data entry
from the beginning, but at least they had their system back. You probably guessed the
ending of this tale, but if not, I need only mention Murphy. Sure enough, someone had
used the tape by writing over it and the system was lost forever. I didn't return to the
company to redo the system and I am not sure of the relationship between the company
where I had worked and the client. I do know that within a few months this computer
company bit the dust.
Returning to our discussion from my digression, I/O problems may be reduced by
consistent hardware maintenance but bad data will require considerably more effort. You
should never have a program that abends because of bad data caused by a field generated
by the system. Any program that accepts input to be used as fields in a file should
guarantee that this field will never result in an abend due to bad data. If the field is
numeric, the program should never accept any other type of data into this field nor should
it ever write out this field to the file if it is not numeric. This may take a bit more
programming but it will result in evenings and weekends with virtually no calls from the
computer room. That will make your time at home more enjoyable.
Problems will occur no matter what you do and no matter how careful you are
designing systems. The steps you take will differ from system to system but you need to
minimize the effects of crashes and software failures. As we get into further sample
programs, I will offer some suggestions to help reduce the frustration without leaving
your place of employment or jumping off a twenty-story building.
