Which method uses a Risk Priority Number to assess improvement efforts?

The method that uses a Risk Priority Number (RPN) to assess improvement efforts is FMEA, which stands for Failure Modes and Effects Analysis. FMEA is a systematic approach used to identify potential failure modes within a system, product, or process, assess their impact, and prioritize the risks associated with them.

The Risk Priority Number is a key component of the FMEA process. It is calculated by multiplying three factors: the severity of the failure's effect, the likelihood of the failure occurring, and the ability to detect the failure before it reaches the customer. By quantifying these factors into a single score, teams can prioritize their improvement efforts on issues that present the highest risk.

In contrast, other methods mentioned, like histograms, Pareto charts, and cause-and-effect diagrams, do not utilize a quantitative RPN for assessment. While they are important tools for analyzing data and identifying root causes, they do not provide a structured way to prioritize risks based on their potential impact and detectability in the same manner as FMEA. This makes FMEA particularly valuable in proactive risk management and continuous improvement initiatives.