Managers resist system testing because it seems redundant and wasteful.
Programmers resist it because itís insulting. But the errors you donít
find because you skip system testing will show up later, either during
acceptance testing or after the programs are operational. The cost of a
problem found that late is very high; you measure it in terms of
customer dissatisfaction, lost opportunities for follow-on work, a
tarnished reputation, and a patched-up product, as well as manpower,
time, and money.
System testing wonít guarantee perfection, but it will bring you a
large step closer than reliance on the programmersí own tests.
Programmers are not stupid or uncaring, of course, but they are too
close to their products. They cannot be expected to test with the
objectivity of users. They know how they intended the programs to
behave, and they test accordingly.
Be ready for system testing when the programmers deliver their
product. Have System Test Specifications written, computer time
scheduled, library facilities set up, and people ready.