Process Metrics
In our process we have started using two metrics in addition to the cumulative flow diagram indicator. These metrics are tracked against target values to measure if the process is in statistical control.
The first metric is the lead time. It measures the time in days between the moment a work item enters our process and the moment it is declared finished and exists the process.
The second metric is the throughput period (the inverse of the throughput rate) which is the time in days between the end dates of successive work items. If we note two cards C1 and C2 with start dates SD1 and SD2 and end dates ED1 and ED2, then the lead time for C1 is (ED1 – SD1) in days and the cadence for that period is ED2 – ED1.
Over a period of time these measures can be plotted against a target mean (10 days of lead time and 4 days of throughput period) and a target deviation (5 days for the lead time and 2 days for the throughput period). These targets can be changed independently as our process matures. Improvement to the means benefit the delivery speed. Improvements to the deviation benefits the predictability.
Finally you will find here the model I use (for Apple’s Numbers) to visualize these process metrics.
