If common causes of variation result in a process operating outside the customer's specifications, the process is improved by reducing the special…

The statement is incorrect because it proposes the wrong solution for the stated problem. When a process is operating outside customer specifications due to common causes of variation, it means the process is stable and in statistical control, but its inherent, natural variation is too wide to meet the requirements. This is a problem of process capability. To resolve this, management must make a fundamental change to the process itself—such as implementing new technology, using better materials, or redesigning the workflow—to reduce the inherent (common cause) variation.

Reducing special causes of variation is the correct action when a process is unstable or "out of control." This action brings the process into a stable, predictable state but does not change its inherent capability. Therefore, addressing special causes will not fix a process that is already stable but incapable of meeting specifications due to its common cause variation.

The "True" option is incorrect because it fundamentally misunderstands the principles of Statistical Process Control (SPC). It incorrectly prescribes the remedy for an unstable process (reducing special causes) to a problem of an incapable but stable process (excessive common cause variation).

1. Montgomery, D. C. (2013). Introduction to Statistical Quality Control (7th ed.). John Wiley & Sons.

Section 4.2, "Control Charts and Process Capability": Montgomery distinguishes between a process being in a state of statistical control and its capability to meet specifications. He states, "A process may be in statistical control, yet its natural variability... may be so large that a high percentage of the output fails to conform to specifications. This is a problem of process capability." (Paraphrased from concepts in Chapter 4). He further explains that improving capability requires fundamental changes to the process, which addresses common cause variation.

2. MIT OpenCourseWare. (2004). 16.842 Fundamentals of Systems Engineering, Fall 2004. Massachusetts Institute of Technology.

Lecture 5: Statistics and Quality Control, Slide 16 ("Deming’s Principles"): The lecture notes explain W. Edwards Deming's concepts. It is stated that special causes are "assignable to a specific event or person" and are "correctable locally." In contrast, common causes are "inherent in the system" and require "management action to correct." The question describes a problem inherent in the system (common causes), which requires management action to change the system, not the local correction of special causes.

3. Wheeler, D. J. (2000). Understanding Variation: The Key to Managing Chaos (2nd ed.). SPC Press.

Chapter 2, "The Two Types of Variation": Wheeler explains that confusing common causes and special causes is a critical management error. He states, "Treating common causes as if they were special causes will only make things worse... To reduce common-cause variation, one must make a fundamental change in the system." The question proposes exactly this error: treating a common cause problem as if it could be solved by addressing special causes.

4. Smith, G. T. (2000). Statistical process control for monitoring and improving project quality. Project Management Journal, 31(2), 29-39.

Page 32, "Process Capability": The article clarifies the appropriate actions. "If the process is in control but not capable of meeting the specifications, management must change the process. This may mean a new machine, a new raw material supplier, or retraining the operators. If the process is out of control, the project manager must find the special cause of variation and remove it." This directly refutes the premise of the question. (DOI not available for this older publication, but it is a widely cited peer-reviewed article in the domain).