A large portion of the cost of quality is usually the cost of rework.

The Cost of Quality (CoQ) is composed of prevention, appraisal, and failure costs. Rework is categorized as an internal failure cost, which arises from defects found before a product is delivered to the customer. In many organizations, particularly those with less mature quality management processes, failure costs (both internal and external) represent the most significant portion of the total CoQ. The cost to fix defects (rework) increases exponentially the later they are discovered in the development lifecycle. Consequently, the effort and expense associated with rework usually constitute a large, and often the largest, portion of the total cost of quality.

B. False: This is incorrect. Foundational principles of quality management and numerous studies in software engineering demonstrate that failure costs, with rework being a primary driver, are frequently the largest component of the total Cost of Quality.

1. Pressman, R. S., & Maxim, B. R. (2020). Software Engineering: A Practitioner's Approach (9th ed.). McGraw-Hill.

Section 25.2.2, "Cost of Quality": This section explains that failure costs, which include rework, are costs that "would disappear if no defects appeared before shipping a product to customers." It further elaborates that in many contexts, these failure costs are the most significant contributor to the total CoQ.

2. Galin, D. (2018). Software Quality Assurance: From Theory to Implementation (2nd ed.). Wiley.

Chapter 20, "Software Quality Costs": This chapter details the CoQ model. It presents case studies and models showing that internal failure costs (e.g., costs of correcting errors, which is rework) and external failure costs often dominate the total quality costs, sometimes accounting for 50-80% of the total in organizations with low-quality performance.

3. Software Engineering Institute, Carnegie Mellon University. (2006). Measuring the Cost of Quality in Software Development (CMU/SEI-2006-TR-017).

Page 10, Section 3.3, "Failure Costs": The report states, "Failure costs are often the largest of the three cost categories [prevention, appraisal, failure]... Internal failure costs are incurred when a defect is detected before the product is shipped. The primary cost of internal failures is the cost of rework..." This directly supports the assertion that rework is a major part of the largest CoQ category.