A QC test can capture the physical, biological, or chemical state of an intermediate, subassembly, or finished well. Each QC test has a defined standard or acceptable value, upper and lowers out-of-tolerance values, and sample and recount values. Process control is a key discipline in the manufacturing process in which a product is made – ensuring better quality and efficiency. Basically, process control combines the disciplines of control engineering and chemical engineering – and uses specialized, often custom-built industrial control systems. Quality control is a process through which a business seeks to ensure that product or industry, and several techniques exist for measuring quality.