Software Quality Management
The notion of "quality" is not as simple as it may seem. For any engineered product, many desired qualities are relevant to a particular project. The section explains software quality fundamentals, including the main SQM processes: quality assurance, verification, validation, review, and audit. Software quality refers to the delivered product of a software development project, but that quality depends on the quality of the "upstream" products from which it was derived, including requirements, design, construction, and the software quality activities that support it during the development, namely, validation, verification, testing, and measurement. Software quality terminology is numerous, informal, formal, and often ambiguous, with multiple categorizations (internal, external, operational, and feature quality). All of this makes software quality interesting to study.
From a domain perspective, software quality applies to both the problem application domain and the solution domains. It applies to all software development activities and all software products. It is interdisciplinary in that it is a topic in management, software engineering, mathematics, statistics, measurement, and more. It intersects the generic categories of human, software, and hardware and refers to the evolving relationships of these generic types. This last observation hints at the next stage in the evolution of computing technology.
Software quality is a major driving factor for computing technology evolution, which is increasing our capabilities to solve complex problems better, faster, on a larger scale, and with more automation. Generally, the problem domain gets smaller as the solution domain gets larger. The solution domain gets larger as hardware and software support becomes automated. More automation often begins with new abstractions we make in the problem domain, resulting in new relationships between hardware and software, eventually manifesting as automated support tools. We give names to these tools: "cloud computing", big databases, programming languages (front-end, network, back-end, and so on), and AI (natural language translation, image recognition, and machine learning). Indeed, software quality is very interesting.
Reviews and Audits
Inspections
The purpose of an inspection is to detect and identify software product anomalies. Two important differentiators of inspections as opposed to reviews are as follows:
- An individual holding a management position over any member of the inspection team shall not participate in the inspection.
- An inspection is to be led by an impartial facilitator who is trained in inspection techniques.
Software inspections always involve the author of an intermediate or final product, while other reviews might not. Inspections also include an inspection leader, a recorder, a reader, and a few (2 to 5) inspectors. The members of an inspection team may possess different expertise, such as domain expertise, design method expertise, or language expertise. Inspections are usually conducted on one relatively small section of the product at a time. Each team member must examine the software product and other review inputs prior to the review meeting, perhaps by applying an analytical technique to a small section of the product, or to the entire product with a focus only on one aspect, for example, interfaces. Any anomaly found is documented and sent to the inspection leader. During the inspection, the inspection leader conducts the session and verifies that everyone has prepared for the inspection. A checklist, with anomalies and questions germane to the issues of interest, is a common tool used in inspections. The resulting list often classifies the anomalies and is reviewed for completeness and accuracy by the team. The inspection exit decision must correspond to one of the following three criteria:
- Accept with no or at most minor reworking
- Accept with rework verification
- Reinspect
Inspection meetings typically last a few hours, whereas technical reviews and audits are usually broader in scope and take longer.