Let's assume your customers requirements are 25 PPM. That means that you would be allowed 25 pieces for every 1,000,000 pieces or 250 defective parts per year. Or to put it another way, one bad part per day! Notice I did not say one bad part per day per person or job, or shift or machine.
The dynamic inheritance allows you to follow open-closed principle by extending classes without modifying existing classes and allows you to choose features that you need at runtime. Of course, dynamic languages such as Ruby make this a lot easier as you can extend classes or objects with modules at runtime, e.g.
A DLL file is indicated by the extension DLL in its name. A Dynamic Link Library (DLL) is a file of code containing functions that can be called from other executable code (either an application or another DLL). Programmers use DLLs to provide code that they can reuse and to parcel out distinct jobs. Unlike an executable (EXE) file, a DLL cannot be directly run.