Test using Quality Characteristics\Factors\Attributes that you create.

It can be useful to define aspects of a product that describe the quality of the application that you are testing. I have found examples of doing this in seven different decades. Sometimes these aspects have been put into sets, lists or groups and have sometimes been called quality characteristics, sometimes quality factors and at other times they have been called quality attributes. These sets, lists and groups have also been used in different ways to improve quality.

Walter Shewhart wrote in 1931 about the “conception of the Quality of a Thing as a set of characteristics[1]”, and in 1939 wrote that the “aim is to produce a sequence of objects having a specified quality characteristic within some specified limits”[2]. The quality characteristics of the objects would be controlled by the use of control charts. 

In 1950 in Japan in his lecture at Mt Hakone, W. Edwards Deming spoke about “communication between buyer and the seller of the quality-characteristics of a product is provided by the same statistical techniques that are used for improved testing, production and inspection”[3]. The statistical technique he was suggesting is that of the control chart. The quality characteristics he spoke about would have been for physical products. 

The Western Electric Statistical Quality Control Handbook was first published in 1956 and describes the Statistical Quality Control process developed by Shewhart that used control charts. The Handbook says that  “the word “Quality” means much more than the goodness or badness of a product. It refers to the qualities or characteristics of the thing or process being studied”[4].

A report for the USAF in 1977 listed quality factors under headings in groups[5], for example under the heading testability it lists simplicity, modularity, instrumentation and self-descriptiveness. The report also recommends which factors should be measured[6], and how to measure them.[6]

Attributes to specify quality were defined in 1988 as “a quality concept or resource concept which describes a system quantitatively” [7]. These attributes are to be “specified and controlled throughout the project”[7]. The attributes could be expressed as a hierarchy, for example:

• System performance
  • Weekly work-load capacity
  • System availability
  • Repose time to questions[8]

In 1998 the list of quality factors from the 1977 report is used as a list of quality attributes. “These attributes include both subjective and objective measures and are only a subset of the total attributes of software programs”, and “the applicable elements should be selected by the quality professional for application to each ..program”[7].

A list of eighteen quality attributes was listed in 2002 under Testing Techniques, with the advice “to determine whether a feature is defective, ask yourself how you would prove that it lacks or violates one of these attributes”[10]

Seven product dimensions, which included a quality attribute dimension, were taken from business analysis to help describe quality in 2015. It is “helpful to consider all seven dimensions during release, feature and iteration planning”[11]

Quality professionals have been using quality characteristics/factors/attributes of a product to describe the quality of products and services for a long time. I have not given an example of their use from the 2020s, it is up to us to find how best to use quality characteristics/factors/attributes to help us with the testing challenges we face today!

Thank you to Dennis Sergent for his help with this blog post. 

References

[1] Economic Control of Quality of Manufactured Product by Walter Shewhart (1931, p55)

[2] Statistical Method from the Viewpoint of Quality Control by Walter Shewhart with a foreword by W. Edwards Deming (1986 – originally published in 1939, p7)

[3] The World of W. Edwards Deming by Cecelia S. Kilian (1992, p62)

[4] Western Electric Statistical Process Control Handbook (1982, p2)

[5] FACTORS IN SOFTWARE QUALITY Concept and Definitions of Software Quality By Jim A. McCall, Paul K. Richards CD Cene, F. Walters (1977, p44)

[5] FACTORS IN SOFTWARE QUALITY Concept and Definitions of Software Quality By Jim A. McCall, Paul K. Richards CD Cene, F. Walters (1977, p38)

[6] FACTORS IN SOFTWARE QUALITY Concept and Definitions of Software Quality By Jim A. McCall, Paul K. Richards CD Cene, F. Walters (1977, p62)

[7] Principles of Software Engineering Management by Tom Gilb (1988, p134)

[8] Principles of Software Engineering Management by Tom Gilb (1988, p136)

[9] Computer Applications to Quality Systems by Frederic I. Orkin and Danliel Olivier in Jurans Quality Handbook 5th Edition edited by J.M. Juran and A. Blanton Godfrey (1998, p10.7)

[10] Lessons Learned in Software Testing by Cem Kaner, James Bach, Bret Pettichord (2002, p60)

[11] More Agile Testing by Janet Gregory and Lisa Crispin (2015, p130)