Lean Six Sigma Black Belt Certification Study Guide 2026

The Box-Cox transformation applies a power function to data to make it more closely approximate a normal distribution for valid statistical analysis.

Process Performance (Pp, Ppk) and Process Capability (Cp, Cpk) are specific indices used to assess process capability for continuous data. However, 'Process Performance' itself is not a continuous data capability index but rather a general term describing the overall performance of a process. The other options refer to specific, recognized statistical indices.

Control charts are statistical tools that visually represent the performance of a process over time, distinguishing between common cause variation and special cause variation. They are often referred to as the 'voice of the process' because they show what the process is actually doing and its inherent capabilities and limits. While crucial for process monitoring, they do not directly reflect customer expectations or team opinions.

The Control Plan is the key deliverable of the Control phase and is essential for sustainability. It documents the new process, outlines the key metrics to monitor, sets control limits, and specifies the response plan if the process becomes unstable. Formally transferring ownership of this plan to the process owner ensures that the improvements are maintained long after the project team disbands.

DFMEA stands for Design Failure Mode and Effect Analysis. It is a systematic proactive method used during the design phase of a product or process to identify potential failure modes, assess their severity, occurrence, and detectability, and prioritize actions to mitigate risks. The "Design" prefix specifies that this FMEA is applied to the product or process design itself, rather than manufacturing or system-level failures.

A significant interaction means the combined effect of factors differs from the sum of their individual effects.