According to the CTSC Exam Content Manual1, statistical process control (SPC) is a key component of a total quality management (TQM) program. SPC is a technique that uses statistical methods and tools to monitor and control the variation and performance of a process. SPC helps to ensure that the process is stable, capable, and predictable, and that the output meets the customer specifications and expectations. SPC also helps to identify and eliminate the causes of defects and errors, and to improve the quality and efficiency of the process. Option B, JIT inventory, is a component of lean manufacturing, not TQM. JIT inventory aims to reduce inventory levels and costs by delivering materials or components just before they are needed in the production process. Option C, autonomous maintenance, is a component of total productive maintenance (TPM), not TQM. Autonomous maintenance involves empowering the operators to perform basic maintenance tasks on their own equipment, such as cleaning, lubricating, inspecting, and adjusting. Option D, SCO, is a component of supply chain management, not TQM. SCO involves optimizing the flow of materials, information, and money across the supply chain network, from the suppliers to the customers.