Why ISO 29119 is a flawed quality standard

Why ISO 29119 is a flawed quality standard

This article originally appeared in the Fall 2015 edition of Better Software magazine.

In August 2014, I gave a talk attacking ISO 29119” at the Association for Software Testing’s conference in New York. That gave me the reputation for being opposed to standards in general — and testing standards in particular. I do approve of standards, and I believe it’s possible that we might have a worthwhile standard for testing. However, it won’t be the fundamentally flawed ISO 29119.

Technical standards that make life easier for companies and consumers are a great idea. The benefit of standards is that they offer protection to vulnerable consumers or help practitioners behave well and achieve better outcomes. The trouble is that even if ISO 29119 aspires to do these things, it doesn’t.

Principles, standards, and rules

The International Organization for Standardization (ISO) defines a standard as “a document that provides requirements, specifications, guidelines or characteristics that can be used consistently to ensure that materials, products, processes and services are fit for their purpose.”

It might be possible to derive a useful software standard that fits this definition, but only if it focuses on guidelines, rather than requirements, specifications, or characteristics. According to ISO’s definition, a standard doesn’t have to be all those things. A testing standard that is instead framed as high level guidelines would be consistent with the widespread view among regulatory theorists that standards are conceptually like high-level principles. Rules, in contrast, are detailed and specific (see Frederick Schauer’s “The Convergence of Rules and Standards”: PDF opens in new tab). One of ISO 29119’s fundamental problems is that it is pitched at a level consistent with rules, which will undoubtedly tempt people to treat them as fixed rules.

Principles focus on outcomes rather than detailed processes or specific rules. This is how many professional bodies have defined standards. They often use the words principles and standards interchangeably. Others favor a more rules-based approach. If you adopt a detailed, rules-based approach, there is a danger of painting yourself into a corner; you have to try to specify exactly what is compliant and noncompliant. This creates huge opportunities for people to game the system, demonstrating creative compliance as they observe the letter of the law while trashing underlying quality principles, (see John Braithwaite’s “Rules and Principles: A Theory of Legal Certainty”). Whether one follows a principles-based or a rules-based approach, regulators, lawyers, auditors, and investigators are likely to assume standards define what is acceptable.

As a result, there is a real danger that ISO 29119 could be viewed as the default set of rules for responsible software testing. People without direct experience in development or testing look for some form of reassurance about what constitutes responsible practice. They are likely to take ISO 29119 at face value as a definitive testing standard. The investigation into the HealthCare.gov website problems showed what can happen.

In its March 2015 report (PDF, opens in new tab) on the website’s problems, the US Government Accountability Office checked the HealthCare.gov project for compliance with the IEEE 829 test documentation standard. The agency didn’t know anything about testing. They just wanted a benchmark. IEEE 829 was last revised in 2008; it said that the content of standards more than five years old “do not wholly reflect the present state of the art”. Few testers would disagree that IEEE 829 is now hopelessly out of date.

when a document is more than five years old

IEEE 829’s obsolescence threshold

The obsolescence threshold for ISO 29119 has increased from five to ten years, presumably reflecting the lengthy process of creating and updating such cumbersome documents rather than the realities of testing. We surely don’t want regulators checking testing for compliance against a detailed, outdated standard they don’t understand.

Scary lessons from the social sciences

If we step away from ISO 29119, and from software development, we can learn some thought-provoking lessons from the social sciences.

Prescriptive standards don’t recognize how people apply knowledge in demanding jobs like testing. Scientist Michael Polanyi and sociologist Harry Collins have offered valuable insights into tacit knowledge, which is knowledge we possess and use but cannot articulate. Polanyi first introduced the concept, and Collins developed the idea, arguing that much valuable knowledge is cultural and will vary between different contexts and countries. Defining a detailed process as a standard for all testing excludes vital knowledge; people will respond by concentrating on the means, not the ends.

Donald Schön, a noted expert on how professionals learn and work, offered a related argument with “reflection in action” (see Willemien Visser’s article: PDF opens in new tab). Schön argued that creative professionals, such as software designers or architects, have an iterative approach to developing ideas—much of their knowledge is understood without being expressed. In other words, they can’t turn all their knowledge into an explicit, written process. Instead, to gain access to what they know, they have to perform the creative act so that they can learn, reflect on what they’ve learned, and then apply this new knowledge. Following a detailed, prescriptive process stifles learning and innovation. This applies to all software development—both agile and traditional methods.

In 1914, Thorstein Veblen identified the problem of trained incapacity. People who are trained in specific skills can lack the ability to adapt. Their response worked in the past, so they apply it regardless thereafter.

young girl, old woman

Young woman or old woman? Means or ends? We can focus on only one at a time.

Kenneth Burke built upon Veblen’s work, arguing that trained incapacity means one’s abilities become blindnesses. People can focus on the means or the ends, not both; their specific training makes them focus on the means. They don’t even see what they’re missing. As Burke put it, “a way of seeing is also a way of not seeing; a focus upon object A involves a neglect of object B”. This leads to goal displacement, and the dangers for software testing are obvious.

The problem of goal displacement was recognized before software development was even in its infancy. When humans specialize in organizations, they have a predictable tendency to see their particular skill as a hammer and every problem as a nail. Worse, they see their role as hitting the nail rather than building a product. Give test managers a detailed standard, and they’ll start to see the job as following the standard, not testing.

In the 1990s, British academic David Wastell studied software development shops that used structured methods, the dominant development technique at the time. Wastell found that developers used these highly detailed and prescriptive methods in exactly the same way that infants use teddy bears and security blankets: to give them a sense of comfort and help them deal with stress. In other words, a developer’s mindset betrayed that the method wasn’t a way to build better software but rather a defense mechanism to alleviate stress and anxiety.

Wastell could find no empirical evidence, either from his own research at these companies or from a survey of the findings of other experts, that structured methods worked. In fact, the resulting systems were no better than the old ones, and they took much more time and money to develop. Managers became hooked on the technique (the standard) while losing sight of the true goal. Wastell concluded the following:

Methodology becomes a fetish, a procedure used with pathological rigidity for its own sake, not as a means to an end. Used in this way, methodology provides a relief against anxiety; it insulates the practitioner from the risks and uncertainties of real engagement with people and problems.

Developers were delivering poorer results but defining that as the professional standard. Techniques that help managers cope with stress and anxiety but give an illusory, reassuring sense of control harm the end product. Developers and testers cope by focusing on technique, mastery of tools, or compliance with standards. In doing so they can feel that they are doing a good job, so long as they don’t think about whether they are really working toward the true ends of the organization or the needs of the customer.

Standards must be fit for their purpose

Is all this relevant to ISO 29119? We’re still trying to do a difficult, stressful job, and in my experience, people will cling to prescriptive processes and standards that give the illusion of being in control. Standards have credibility and huge influence simply from their status as standards. If we must have standards, they should be relevant, credible, and framed in a way that is helpful to practitioners. Crucially, they must not mislead stakeholders and regulators who don’t understand testing but who wield great influence and power.

The level of detail in ISO 29119 is a real concern. Any testing standard should be in the style favored by organizations like the Institute of Internal Auditors (IIA), whose principles based professional standards cover the entire range of internal auditing but are only one-tenth as long as the three completed parts of ISO 29119. The IIA’s standards are light on detail but far more demanding in the outcomes required.

Standards must be clear about the purpose they serve if we are to ensure testing is fit for its purpose, to hark back to ISO’s definition of a standard. In my opinion, this is where ISO 29119 falls down. The standard does not clarify the purpose of testing, only the mechanism—and that mechanism focuses on documentation, not true testing. It is this lack of purpose, the why, that leads to teams concentrating on standards compliance rather than delivering valuable information to stakeholders. This is a costly mistake. Standards should be clear about the outcomes and leave the means to the judgment of practitioners.

A good example of this problem is ISO 29119’s test completion report, which is defined simply as a summary of the testing that was performed. The standard offers examples for traditional and agile projects. Both focus on the format, not the substance of the report. The examples give some metrics without context or explanation and provide no information or insight that would help stakeholders understand the product and the risk and make better decisions. Testers could comply with the standard without doing anything useful. In contrast, the IIA’s standards say audit reports must be “accurate, objective, clear, concise, constructive, complete, and timely.” Each of these criteria is defined briefly in a way that makes the standard far more demanding and useful than ISO 29119, in far less space.

It’s no good saying that ISO 29119 can be used sensibly and doesn’t have to be abused. People are fallible and will misuse the standard. If we deny that fallibility, we deny the experience of software development, testing, and, indeed, human nature. As Jerry Weinberg said (in “The Secrets of Consulting”), “no matter how it looks at first, it’s always a people problem”. Any prescriptive standard that focuses on compliance with highly detailed processes is doomed. Maybe you can buck the system, but you can’t buck human nature.