Quality assurance, quality control and inspection, are terms commonly used interchangeably. The accuracy and precision to be attained depends on several determining factors. Since not all machines have the same level of reliability and capability to execute predictable finished results within certain tolerances, nor all manufacturing processes achieve the same range of exactness, the machine shop is then limited to its own dependability in delivering the desire outcomes. Subsequently, subject to the rigor declared by the customer, the machine shop may be required to undergo a verification and validation even prior to the issuance and acknowledgment of an order.