A definition of quality control is:
The process of inspecting products to ensure that they meet the required quality standards
This method checks the quality of completed products for faults. Quality inspectors measure or test every product, samples from each batch, or random samples – as appropriate to the kind of product produced.
The main objective of quality control is to ensure that the business is achieving the standards it sets for itself.
In almost every business operation, it is not possible to achieve perfection. For example there will always be some variation in terms of materials used, production skills applied, reliability of the finished product etc.
Quality control involves setting standards about how much variation is acceptable. The aim is to ensure that a product is manufactured, or a service is provided, to meet the specifications which ensure customer needs are met.
There are several methods of quality control.
At its simplest, quality control is achieved through inspection. For example, in a manufacturing business, trained inspectors examine samples of work-in-progress and finished goods to ensure standards are being met.
For businesses that rely on a continuous process, the use of statistical process control ("SPC") is common. SPC is the continuous monitoring and charting of a process while it is operating. Data collected is analysed to warn when the process is exceeding predetermined limits
Advantages of quality control
With quality control, inspection is intended to prevent faulty products reaching the customer. This approach means having specially trained inspectors, rather than every individual being responsible for his or her own work. Furthermore, it is thought that inspectors may be better placed to find widespread problems across an organisation.
Disadvantages of quality control
A major problem is that individuals are not necessarily encouraged to take responsibility for the quality of their own work.
Rejected product is expensive for a firm as it has incurred the full costs of production but cannot be sold as the manufacturer does not want its name associated with substandard product. Some rejected product can be re-worked, but in many industries it has to be scrapped – either way rejects incur more costs,
A quality control approach can be highly effective at preventing defective products from reaching the customer. However, if defect levels are very high, the company's profitability will suffer unless steps are taken to tackle the root causes of the failures.