Since i am working on Machinery manufacturing,this
"betatesting" of uncomplete systems can be done,
we all test all parts of each machine separately,
and when you join all together,you can left out more than
80% of problems,also is easier to solve problems on some
"module" in your real "workbench" than trying to solve it mixed with all the
metallic structure of the machine itself.if we only test each finished machine,
we just lose days and days of work leaving parts already
mounted,removing covers,leaving electrical installation,
fitting new pieces.this kind isn`t very pleasured, i can tell you for sure.