Lee Copeland takes a look at quality assessment through the filter of John Godfrey Saxe's poem "The Blind Men and the Elephant" and offers an important lesson: When assessing quality, make sure everyone on your project is looking for the same thing.
You probably remember the story of the blind men describing an elephant. American poet John Godfrey Saxe (1816-1887) immortalized the story in his poem, "The Blind Men and the Elephant." It begins:
It was six men of Indostan
To learning much inclined,
Who went to see the Elephant
(Though all of them were blind),
That each by observation
Might satisfy his mind.
The men alternately describe the elephant as a wall, a spear, a snake, a tree, a fan, and a rope. The poem ends:
And so these men of Indostan
Disputed loud and long,
Though each was partly in the right,
And all were in the wrong!
So oft in theologic wars,
The disputants, I ween,
Rail on in utter ignorance
Of what each other mean,
And prate about an Elephant
Not one of them has seen!
In her book, Achieving Software Quality Through Teamwork , Isabel Evans describes an equivalent situation regarding quality: Everyone talks about it; no one really knows what it is; but we have teams whose mission is to "assure" it. Isabel describes five different views of quality: product-based, manufacturing-based, user-based, value-based, and transcendent.
The product-based definition focuses on conformance to a set of quality attributes. Often, the ISO 9126 standard is used as the basis. ISO 9126 defines a taxonomy of six quality characteristics and twenty one more detailed subcharacteristics. Quantitative criteria are established for each subcharacteristic, and product quality is objectively evaluated against those criteria.
The manufacturing-based definition focuses on conformance to requirements. This is the classic quality definition first enunciated in 1980 by Phil Crosby in his book, Quality Is Free . Product quality depends on the extent to which the product requirements have been met, while process quality depends on the extent to which the defined processes have been followed.
The user-based definition focuses on "fitness for use." Quality is determined by the users' ability to work more efficiently and effectively by using the product. Under this definition, the focus is on real users of the product, not the product's attributes or requirements.
The value-based definition focuses on the value to the organization that the product provides. Rather than consider the users' evaluations, this approach considers the time and cost savings measured against the costs of developing, operating, and maintaining the product to determine the product's return on investment. A significant ROI means a quality product; a less significant ROI means a lower quality product.
Writing about the Supreme Court's attempts to define obscenity, Justice Potter Stewart explained, "I shall not today attempt further to define [obscenity] . . . but I know it when I see it." The transcendent definition of quality takes exactly the same approach—"I cannot define it, but I know quality when I see it." We evaluate quality every day using this method. Transcendent definitions emerge from our expectations, experiences, preferences, emotions, likes and dislikes, loyalties, politics, and aesthetics.
And so we ask the classic question, "Which of these five definitions is right?" And we respond with the consultant's standard answer: "It depends.”"
Isabel believes that within a project, if differing views of quality are not resolved, each group will optimize its own efforts toward its own view of quality. The groups will suboptimize their work because they do not value the opinions and thus the contribution that other approaches provide.
And so, may I offer a suggestion: Before you set off to "assure quality," attempt to come to consensus about what “quality” means for your product and your project. As you do, remember that your stakeholders’ view of quality is probably more important than
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