An intuitive definition of “quality” could be the “lack of defects” in a product.
However, such a definition appears to be more suited to defining the “defectiveness” of a product, rather than its quality. Certainly defectiveness is not a suitable comparison parameter, unless it is associated to other relevant parameters, such as cost.
As an example, should we choose between two products, the first defect-free and the second full of defects, for the same price? Obviously we would prefer the first one. However, if the cost of the first product were considerably higher than the second, perhaps some would choose the second despite its defects.
Quality of a product/service
The official definition of quality reported in standard ISO 8402:1986 is “the totality of features and characteristics of a product or service that bears its ability to satisfy stated or implied needs”.
Therefore quality is not an attribute of the product or service itself, but refers to the use of such product or service, as per 2004 M. Juran definition: ”Quality is fitness for use”.
UNI EN ISO 9000 standard (2000 edition) had the merit of turning the focus from the product or service to the set of corporate processes concurring to its realization. In fact the realization of good products or services can only result from well managed and well controlled processes.
Hence the need for specifying which are the subjects and elements involved in the determination of the quality of a product or a service and its related processes.
- Who determines the requirements? Usually the buyer or the user (being often the same subject).
- Who provides the product or the service? The company, agency, public or private organization.
- The product must ensure a well-defined quality. That is, design and manufacturing must comply with well-defined specifications and standards, to avoid defects.
- Measurable factors are the main instrument for the customer to evaluate the supplier’s compliance with requirements.
For related processes:
- Corporate processes must be measurable by means of suitable indicators of quality and key performances.
- Periodic surveillance of such indicators is a fundamental instrument for management to evaluate the quality of a process and its possibility for improvement.
- Since in a Supply Chain, internal processes interact with other external processes (with customers and suppliers), the project must define such interface.
For products, services, projects and processes:
- Quality means capability to reach defined objectives (efficacy), optimizing the use of time, human and economic resources (efficiency);
- The documents resuming the characteristics of the product/service are: contracts, technical specifications, regulations, standards, quality plans. In every document acceptance criteria must be specified.
Quality is a general concept but applicable to all human realities. The variable is the system utilized by both customer and supplier to evaluate it.