Total cycle time is computed as days between the 4-Way Confirmed Date/Time (present on every job) and the Major Tasks Completion milestone date.

Stage cycle times use consecutive milestone dates: 4-Way Pass → WRB Pass → Base Install Complete → Major Tasks Completion. Because intermediate milestones rolled out partway through the dataset, stage statistics are based on smaller samples.

Building Type is derived from the "Building Flag" column: 0 = single-family (SF), 1 = multifamily (MF). Multifamily jobs run noticeably longer than single-family across every division.

Cost correlation. The labor cost vs. cycle time analysis uses Pearson r (linear correlation, sensitive to outliers) and Spearman ρ (rank correlation, robust to outliers and non-linear relationships). Jobs with zero or missing labor cost are excluded from this section. The scatter plot is sampled to 800 points for readability and the X-axis is clipped at $50,000 to keep a small number of very expensive jobs from compressing the visible cluster — extreme cost outliers are still included in all summary statistics.

Outlier handling for summary statistics: jobs with negative cycle times (Major Tasks Completion before start) and jobs with cycles longer than 365 days are excluded from medians/means but remain visible in the per-job table with a flagged status. Jobs with WRB Pass dated after Base Install Complete suggest milestone-entry errors and are excluded from the WRB→Base stage calculation but kept in totals.

Median vs. mean. Cycle-time data is right-skewed: a few long-running jobs pull averages well above what most jobs experience. The median better represents a "typical" job.