PROCESS QUALITY CONTROL and related terminology

PROCESS QUALITY CONTROL:
Precision — a measure of agreement among repeated measurements of the same property under identical, of substantially similar, conditions; expressed generally in terms of the standard deviation.
Process — a set of interrelated resources and activities that transforms inputs into outputs. Examples of processes include analysis, design, data collection, operation, fabrication, and calculation.
Standard operating procedure — a document that details the method for an operation, analysis, or action with thoroughly prescribed techniques and steps to be followed. It is officially approved as the method for performing certain routine or repetitive tasks.
Manufacturing process control and quality assurance is the set of policies, procedures, and processes used to ensure the quality of a product or a service. It improves the quality of the products and services produced, thereby improving market share, sales growth, sales margins, and competitive advantage; it also helps in avoiding litigation. Quality control methods in industrial production lead to the production of more reliable goods, with fewer defects.
For process control and improvement to be effective, a basic understanding of the process must be obtained. A multi-disciplined team should be established to develop the process Control Plan. All the available information should be utilized to gain a better understanding of the process, such as:
process flow diagram
system/design/process failure mode and effects analysis
special characteristics
lessons learned from similar parts
team’s knowledge of the process
design reviews
The process control plan provides a documented “summary description” of the methods used to minimize process and product variation. It provides a structured approach for the design, selection and implementation of value added control methods. It is not intended to replace the detailed information contained in operator work instructions.
STEPS FOR PROCESS CONTROL:
Process Operation: process step being considered.
Machine, Tool or Device: equipment used to perform a particular process step or operation.
Control Characteristic: process parameter being controlled. In the case of plastic processing equipment this list can become quite lengthy.
Method: means used to control the particular process parameter.
Frequency: how often the process control takes place.
Control Method: manner in which evidence of the process control is recorded.
Reaction Plan: actions that will take place if the process control fails.
Performance Measurement: standard against which the success of the process control is measured.