Concentric design is an approach which is appropriate in database design. The costs associated with developing quality into the application from design to implementation are much lower than the costs of correcting problems which occur later due to poor design . Much attention has been given over the years to process quality improvement. When deviations from the problem domain are found, they are resolved and the process is modified as needed. This is a reactive form of quality management.
Quality assurance attempts to maintain the quality standards in a proactive way.
In addition to using quality control measures, quality assurance goals go further by surveying the customer to determine their level of satisfaction with the product. Conceivably, potential problems can be detected earlier. All too often, specific performance requirements are either ignored during the design process or evaluated after implementation. While performance, per se, may be more of an implementation issue, it should be considered as an aspect of overall database quality. Both relational and object databases can contain rather serious problems in terms of data redundancy, relationships, integrity, and structure.