It is better if we build quality into the product instead of trying to test quality in

“Cease dependence on inspection to achieve quality. Eliminate the need for inspection on a mass basis by building quality into the product in the first place.” [1] is one of W. Edwards Deming’s 14 Points for Management.  Inspection can be defined as testing after development has been completed. Some people have interpreted Deming’s point as an argument against testing. However, “Dr. Deming is often misunderstood on this point. The key word is dependence.”[2] “Is Deming saying that we should abolish inspection? No. of course not” [3].

“Dependence on mass inspection is fraught with danger and with high cost”. [4] An example of a development team being dependent on mass inspection would be a team that relies on manual regression testing before making a release. The manual regression testing will probably find bugs which probably need to be fixed. The bugs that need fixing are rework and fixing them will cost the company time and money. 

“Building quality into the product”[1] is cheaper for the company than inspection and is something that testers can play an important role in. It is cheaper because the earlier in the process an issue is found the cheaper it is to resolve, for example, it is cheaper to fix a fault in a specification than it is to fix a bug in production. Testers can help write and review specifications, and so help find issues early in the process. When we do so we are helping to build quality into the product.

“Inspection is too late. The quality, good or bad is already in the product”[5]. To build quality into the product we need to test as early as possible, for example, testing the designs of a feature before the feature is developed [6]. 

 “Deming said that quality isn’t so much about improving the product as it is about improving the process”[7]. Exploratory testing can help improve the process by identifying issues in the product. These issues can show faults in the development process. “There is a world of difference between, on the one hand dependence on inspection as an attempt to provide the customer with something he won’t complain about and, on the other, the use of inspection to provide guidance toward improvement of a stable process”[8].

The second part of the Deming Cycle, also known as the plan-do-study-act cycle, is to “carry out the change or test decided upon”[9]. Deming does not say who should carry out the testing. Testers’ knowledge of testing techniques will help the team conduct the tests the team needs to build quality into the product. 

An operational definition is a tool that can be used to build quality into a product or service. An operational definition requires there to be a specification for an item, for there to be criteria to show whether the item has met the specification and a decision on whether the item met the criteria.[10] Operational definitions are something that testing professionals can a team use to build quality into the product. Automated tests can help a team decide whether its product meets the criteria in operational definitions. Developing automated tests that give developers the confidence to release their software and find bugs before code is deployed to production is another way that testing professionals help to build quality into the product. 

Testing professionals have analytical skills and using systems thinking for analysis will help the team gain a better understanding of their situation. Systems thinking is a part of Deming’s System of Profound Knowledge.[11] Testers can help their teams build quality into the product by using systems thinking to understand the systems that our product is part of, for example, systems thinking can be used to understand that the company and its customers are one system.

“Inspection merely discovers a lack of quality” [12]. If, instead of only inspecting the product, testers help their team build quality into the product testers will be helping their team to improve and helping to improve the quality of the product. By helping to build quality into a product, testers will also develop a broad skill set that will serve their team, their company and themselves well. 

References

[1] Out of the Crisis by W. Edwards Deming (1986, p23)

[2] Four Days with Dr. Deming by William J. Laztko and David M. Saunders (1995, p48)

[3] The Deming Dimension by Henry R. Neave (1990, p297)

[4] The Deming Dimension by Henry R. Neave (1990, p298)

[5] Out of the Crisis by W. Edwards Deming (1986, p29)

[6] Why should we test in the design phase? How should we go about it? by Melisa Fisher

[7] Deming’s Journey to Profound Knowledge by John “Botchagalupe” Willis with Derek Lewis (2023, p193)

[8] The Deming Dimension by Henry R. Neave (1990, p298)

[9] Out of the Crisis by W. Edwards Deming (1986, p88)

[10] Out of the Crisis by W. Edwards Deming (1986, p277)

[11] The New Economics by W. Edwards Deming (1994, p95)

[12] Deming’s Journey to Profound Knowledge by John “Botchagalupe” Willis with Derek Lewis (2023, p193)

Additional resources:

• What’s North of the North Pole? By John Willis
• DemingNEXT eLearning from the Deming Institute with a two-week free trial
• Going Beyond Quality Makes No Sense – There is No Border to Move Beyond by John Hunter
• systems thinking  – articles on the Deming Institute website