Which of the following would likely not be a CTQ (Critical-to-Quality) for the purchase of a product?

Critical-to-Quality (CTQ) characteristics are the key measurable attributes of a product or process that must meet specific standards to satisfy the customer. They translate broad customer needs into quantifiable requirements. Functionality (does it perform its intended task?), Durability (how long does it last?), and Dependability (how reliably does it perform over time?) are all fundamental aspects of product quality that are of high importance to customers. Therefore, all of these are very likely to be identified as CTQs during the Voice of the Customer (VOC) analysis in the Define phase of a Six Sigma project. Since all listed options are valid examples of CTQs, none of them would be excluded.

A. Functionality: This is a primary customer requirement. If a product does not function as expected, it fails to meet the most basic quality standard and is a classic example of a CTQ.
B. Durability: A product's lifespan and resistance to wear are critical factors for customer satisfaction and value perception, making durability a common and important CTQ.
C. Dependability: This attribute, also known as reliability, measures the consistency of a product's performance. It is a crucial quality characteristic and a frequent source for CTQs.

1. Griffin, A., & Hauser, J. R. (1993). The Voice of the Customer. Marketing Science, 12(1), 1–27. This foundational paper discusses how customer needs (such as dependability, durability, and functionality) are translated into specific, measurable engineering characteristics, which is the essence of a CTQ. The entire article is premised on capturing these types of attributes.

2. Antony, J., & Banuelas, R. (2002). Key ingredients for the effective implementation of Six Sigma program. Measuring Business Excellence, 6(4), 20-27. https://doi.org/10.1108/13683040210451679. The article emphasizes that Six Sigma projects focus on improving business performance by addressing customer needs, which are defined by CTQs like reliability (dependability) and performance (functionality).

3. MIT OpenCourseWare. (2009). 16.851J / ESD.35J Engineering Systems Analysis for Design, Lecture 5: The Voice of the Customer. Massachusetts Institute of Technology. Retrieved from https://ocw.mit.edu/courses/16-851j-engineering-systems-analysis-for-design-fall-2009/resources/mit16851jf09lec05/. Slide 12 ("The CTQ Tree") and the surrounding lecture notes explain the process of breaking down general customer needs into specific, measurable CTQs, using examples that fall under categories like functionality and reliability.