CAPM Practice: Demonstrate an understanding of common problem-solving tools and techniques

A data point outside the control limits signals special cause variation — something unusual has occurred in the process. The project manager should investigate the cause immediately rather than ignoring or adjusting the limits. One point outside the limits is sufficient to trigger investigation.

**Why not A:** Expanding control limits to include an outlier defeats the purpose of statistical process control. Control limits are calculated based on the process's natural variation and should not be adjusted to accommodate anomalous data points.

**Why not B:** Removing the data point as a measurement error without investigation is premature and could mask a real problem. Data points outside control limits should be investigated, not dismissed, as they may indicate a genuine process issue.

**Why not D:** Waiting for additional out-of-control points before acting is risky. A single point outside the control limits is a sufficient signal to warrant investigation. Delaying action could allow a process problem to worsen and produce more defects.