The molding process is comprised of four process elements that the molding technician has control of.
If you change one you will change them all. and on top of this by the time he receives the mold all the problems he will encounter are designed into it , so his challenge is to find a process to overcome the design errors. In addition the material has variation and the press does not always repeat and then the quality department may have some subjective aesthetic requirement that must be interpreted on a constant basis. If that is not bad enough then you have molding and quality technicians from each shift that can that add their own spin on how to mold the product better using their process.
The intent of this site is to try to simplify a rather complex and involved manufacturing process.
If asked to describe the Molding process in simple terms, it would be that we were adding energy into the plastic to change its physical state, inject it into a mold, and remove the energy as fast as possible. Then the final stage is to eject the finished part.
Now what can complicate this concept are the time elements and its interdependence on the final mold part dimensions and look of the part. Knowing how to find the right combination of mold steel, cooling, runner sizes, part wall sections, or part design is the fun part and each time we change one of these components it will affect all of them.