Quality con (software design)

The quality concept

1. Quality is a concept that can rarely be related to any absolute
2. Quality in design is associated with visual properties
3. Software is an abstract product
4. For software, it is difficult to separate ideas about design quality from ones thinking abou

Assessing quality design quote

When you can measure what you are speaking about, and express it in numbers, you know something about it, but when you cannot measure it, when you cannot express it in numbers, your knowledge is of meager and unsatisfactory kind. - Lord Kelvin

3 framework of assessments

1. Quality concept
2. Measurable quantity
3. Counts

Abstract ideas about what constitutes a good or bad properties of a system, and which will need to be assessed by designer when making decisions about design choices.

Quality concepts

Provide the mappings between the abstract concept of quality and countable items (general concept of metric?

Measurable quantities

Concerned with the realization of the mappings, that is the attributes of a representation that will need to be counted in order to obtain some form of value for the metrics.

Counts

Abstraction of quality

Quality concept

Metric definition

Measurable quantities

Realization of metric

Counts

Identifies the purpose of making measurements (static vs dynamic qualities)

Use

Determine the quality concepts that are associated w the purpose (the ilities)

Quality factors

Relate the requirements-oriented properties of the intended system (the ilities) to the solution-oriented properties of the design itself, these are then mapped onto a chosen set of metrics

Quality criteria