Quality control can have different meanings in different contexts.  The key to QC is to define standards to which you are trying to hold yourself.  For example, OSE is starting to define what it means to do a product release - it should have X, Y, and Z.  CAD should be done using this tool, results posted to that website, etc.  If a product release meets those criteria, then we can claim that it is a quality release.

Quality Control for the CEB Press has two factors:  quality of the machine itself and quality of the product it (in turn) produces.  The Liberator, as a device, should be able to function without failure for some reasonable amount of time.  How much, I cannot say.  Suppose we put a goal for  Mean Time Between Failures (BTBF) at 100 hours.  Having established a quality metric, we must then measure the machine to determine it's quality.  That means keeping detailed records of the operation of the CEB Press, carefully noting when it fails and how.  You even need to define what a failure is.  Is a jam a failure?

So you can see that there are two activities that need to be coordinated:  development of standards and measurements against those standards.  Furthermore, for there to be general trust in results, the data collection must be done in a rigorous manner.  We are not doing anyone a favor by "ignoring" a small breakdown and not noting it as such.

Other machines will be measured in efficiency and energy consumption.  The steam engine, for example, will be measured on how well it converts steam energy into mechanical energy (and ultimately electrical power).

Still other machines will be primarily measured by their accuracy.  The CNC Circuit Mill will be measured on how small and how close circuit lines can be milled and how many errors it produces on a board.

In sum, James, Quality Control is a deep subject when it comes to the details, but conceptually it is simple.

- Mark