We Cannot Trade Quality for Schedule or Budget!

It is not uncommon for people to say, “Fast, cheap, or good—choose two.” Most people interpret this to mean that if you want a short schedule and a low budget, you must sacrifice quality. And the corollary is that if you want quality, you must expect a longer schedule or higher costs. But “quality” is not one of the “Triple Constraints”! The PMBOK® teaches us that every project must balance time, cost, and scope. When budget and schedule are constrained, it is scope that must be given up, not quality! And it is increasing scope (not quality) that increases costs...
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We Cannot Trade Quality for Schedule or Budget!Expert Reference Series of White Papers We Cannot Trade Quality for Schedule or Budget!1-800-COURSES www.globalknowledge.comWe Cannot Trade Quality forSchedule or Budget!Alan S. Koch, Global Knowledge Instructor, PMPAbstractIt is not uncommon for people to say, “Fast, cheap, or good—choose two.” Most people interpret this to meanthat if you want a short schedule and a low budget, you must sacrifice quality. And the corollary is that if youwant quality, you must expect a longer schedule or higher costs.But “quality” is not one of the “Triple Constraints”! The PMBOK® teaches us that every project must balancetime, cost, and scope. When budget and schedule are constrained, it is scope that must be given up, not quali-ty! And it is increasing scope (not quality) that increases costs or schedules.Quality vs. GradeWhere did people get the idea that quality costs more? It comes from confusion between the concepts of qual-ity and grade.“Grade” refers to the set of attributes on which the quality of aproduct will be judged. For example, you can buy beef in various “Grade” refers to the set ofgrades (like “prime” and “select”). The government has defined a attributes on which the qualityset of attributes for each grade concerning things like fat and gristle of a product will be judged.content. A low-grade cut of beef that meets all of the requirementsfor its rating is indeed high-quality. While a high-grade cut that hasbeen in the display case too long is lacking in quality (even though it still meets the definition for its grade).The grade of the product to be produced is one of the components of project scope, and so it can be traded forcost or time. If you want a software product with lots of bells and whistles, then it will cost you more time ormoney, while only one bell and two whistles will be significantly cheaper. The adage, “Fast, cheap, or good—choose two,” is valid as long as we interpret the word good to be referring to grade, and not qualityOnce the requirements for the product have been agreed upon, its quality refers to the degree to which itmeets those requirements. Producing a poor-quality product does not save time or money. In fact, as we willdiscuss later, quality problems actually cost us time and money.Cost of QualityThe confusion between grade and quality is reinforced (especially in software development), because most ofus don’t adequately measure the cost of quality. Cost of quality has three components: defect detection; defectcorrection; and defect prevention. Many organizations measure only the defect detection activities, and allowthe other two to be hidden within other costs.Copyright ©2006 Global Knowledge Training LLC . All rights reserved. “PMBOK” and “Project Page 2Management Body of Knowledge” are registered trademarks of the Project Management Institute.Defect DetectionDefect Detection is the set of activities that we normally associate with Cost of Qualitysoftware quality: preparing for testing; running tests; doing peer reviewsor software inspections; and maintaining testing tools, infrastructure, • Defect Detectionand the testing group. These costs are almost always counted as quality • Defect Correctioncosts and show up in the budget (both project and department) as our • Defect Preventioncost of quality.Increasing the focus on product quality means allocating more resources to these activities. Since these tend tobe seen as non-value-added overhead activities, increasing their costs is difficult to justify. That is why it isimportant to consider the other two components of cost of quality to determine what activities are justified.Defect CorrectionDefect Correction is the set of activities that are triggered by the discovery of defects. Of course it includesreporting defects and managing the defect reports. But that is a relatively small part of the cost. The majordefect correction cost is incurred by the engineers who must investigate and diagnose the problems, devise anappropriate fix, and rework the product to bring it into compliance. In addition, this includes the cost to testthe fix and regression test the system to ensure that the fix did not introduce other problems. And if the prob-lem was reported from the field, it includes the cost of distributing the fix and supporting the customers whoencounter the problem.On most software projects, the engineering cost just described is merely counted as engineering cost, makingit an invisible cost of quality. Every time the engineers must fix a problem, the cost of the project increases. Butthat increase is not accounted for as a cost of quality. In addition, the re-testing is counted as a defect detec-tion cost, hiding it in the wrong part of our cost of quality.Defect Correction is often the cause of budget and schedule problems on projects, as the engineers and thetesters both spend unanticipated time and money dealing with defect correction.Defect PreventionDefect Prevention includes any activity that can prevent defects from being put in the product in the firstplace. This includes requirements engineering, architecture and design activities, coding standards, processimprovement, and project retrospectives. Most organizations count these as overhead activities that are notrelated to project performance, and so they minimize them or avoid them altogether.If these were counted as costs of quality, then they could easily be managed to ensure that they are justified,as we will discuss next.Minimizing Total Cost of QualityThe way to control the budget and schedule on a project is to minimize the total cost of quality. Because manyof us o ...