Quality is often described in project management methodologies such as PRINCE2 as conformance of a project deliverable with predefined customer acceptance criteria.
This is not how I naturally think of Quality.
I think of a Quality product as a product that is well designed, with the needs of its target users and markets carefully considered, and in producing the product it is well made so that it is durable, reliable, effective for its purpose, a pleasure to use, etc. The quality of materials used, the thought that goes into the design, and the workmanship are excellent.
Similarly, a Quality service would be a service that is well designed, responsive to the needs and circumstances of the customer, use excellent and appropriate materials (for example information sources relevant to the service), and the performance of the delivery of the service would be excellent.
In both cases, perhaps Quality might be characterised also by the underlying attitude towards the customer or the recipient of the service – is the design and delivery of the product or service well intentioned, focused in a positive way on the recipient of the product or service and their needs?
Quality, by this standard, would be much like Quality in Robert Pirsig’s classic book – Quality is rather difficult to precisely define and measure, but we all know it when we see it.
Perhaps that is why project management methodologies go for the simpler option, and say ‘quality in a project deliverable is what the customer says is required’. But this seems to miss the point, the spirit of Quality, which is captured in the spirit of excellence in the design and delivery in addition to the fitness for purpose of the product, and the level of customer satisfaction.
If quality is defined as just providing what the customer says is required, how can Quality surpass expectations?
The standard concept of quality is only applicable in a static and well known environment. Then you can perfectly define specifications, and any deviation from that during execution of the plan is lowering quality. This implies that basically, yo can't over-achive. Quality management is about getting as close to 100% as possible.
Trouble is that there are few parts of the world which are static and well known.
Thus if this idea of quality is used when it does not fit, it prevents learning (since you have to stick to a plan and goals that you fixed at a time when you were still more stupid). And it binds resources.
Pirsig's static quality is different, it's something non-trivial. And his dynamic variant is even better, but can't be described in the terms of the standard "quality" discussion.