SPC on the outputs is more preferred than SPC on the inputs when implementing SPC for your process.

The statement is false. According to the core principles of modern quality management and Lean Six Sigma, it is far more effective and efficient to apply Statistical Process Control (SPC) to the critical process inputs (the 'Xs') rather than the outputs (the 'Y'). This represents a shift from a reactive, detection-based approach to a proactive, prevention-based strategy. By monitoring and controlling the key input variables that cause variation, an organization can prevent defects from occurring in the first place. Monitoring only the output means defects are identified after resources have already been consumed, leading to waste in the form of scrap, rework, and inspection costs.

A. True: This option is incorrect because it advocates for a reactive quality control strategy (detection) over a proactive one (prevention), which is contrary to the fundamental principles of SPC and Six Sigma.

1. Montgomery, D. C. (2013). Introduction to Statistical Quality Control (7th ed.). Wiley. In Chapter 1, Section 1.2, "Quality, Productivity, and Competitive Position," the text emphasizes that quality improvement is achieved by reducing process variability. The text states, "If variability decreases, the performance of the process improves... This is a proactive quality philosophy" (p. 6). This proactive philosophy focuses on controlling the process inputs and parameters that cause variability, rather than just inspecting the final output.

2. Pyzdek, T., & Keller, P. A. (2018). The Six Sigma Handbook (5th ed.). McGraw-Hill Education. Chapter 21, "Statistical Process Control (SPC)," explains that the purpose of SPC is to control the process. The entire Six Sigma methodology is built on the Y = f(X) equation, which posits that to control the output (Y), one must identify and control the critical inputs (the vital few Xs). Applying SPC to inputs is a direct application of this principle.

3. 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. This article discusses the critical success factors for Six Sigma, highlighting the focus on process understanding and control. It states, "Six Sigma is a business strategy that focuses on understanding and reducing variation in all processes... The goal is to improve processes so that products and services are produced defect-free" (p. 21), which inherently supports controlling inputs to prevent output defects.