Multi Color Computer Embroidery
Quality control is a process by which entities review the quality of all factors involved in production. This approach places an emphasis on three aspects:
1. Elements such as controls, job management, defined and well managed processes, performance and integrity criteria and identification of records.
2. Competence such as knowledge, skills, experience and qualifications.
3. Soft elements such as personnel integrity, confidence, organizational culture, motivation, team spirit and quality relationships.
The quality of the output is at risk if any of these three aspects is deficient in any way.
Total Quality Control is the most important inspection control of all especially in cases where despite statistical quality control techniques or quality improvements implemented, sales decrease. If the original specification does not reflect the correct quality requirements, quality cannot be inspected or manufactured into the product. For instance, the parameters for a pressure vessel should include not only the material and dimensions, but also operating, environmental, safety, reliability and maintainability requirements.
Total Quality Control
Quality Assurance, or QA for short, refers to a program for the systematic monitoring and evaluation of the various aspects of a project, service or facility to ensure that standards of quality are being met.
It is important to realize that the program sponsor determines quality. QA cannot absolutely guarantee the production of quality products, unfortunately, but makes this more likely.
Two key principles characterize QA: “fit for purpose”- the product should be suitable for the intended purpose and “right first time”- mistakes should be eliminated. QA includes regulation of the quality of raw materials, assemblies, products and components; services related to production and management, production and inspection processes.
It is also important to realize that quality is determined by the intended users, clients or customers. Even goods with low prices can be considered quality items if they meet the market need. QA is more than just testing the quality of aspects of a product, service or facility, it analyzes the quality to make sure it conforms to specific requirements and comply with established plans.
A valuable process to perform on a whole consumer product is failure testing or stress testing. In mechanical terms this is the operation of the product until it fails, often under stresses such as increasing vibration, temperature and humidity. This exposes many unanticipated weaknesses in a product and the data are used to drive engineering and manufacturing process improvements. Often quite simple changes can dramatically improve product service, such as changing to mold resistant paint or adding lock-washer placement to the training for new assembly personnel.
Many organisations use statistical process control to bring the organisation to Six Sigma levels of quality. In other words, the likelihood of an unexpected failure is confined to six standard deviations on the normal distribution. This probability is less than 4 one-millionths. Items controlled often include clerical tasks such as order entry as well as conventional manufacturing tasks.
Traditional statistical process controls in manufacturing operations usually proceed by randomly sampling and testing a fraction of the output. Variances in critical tolerances are continuously tracked and where necessary, corrected before bad parts are produced.