Monitoring Your New Process for Business Success
After you analyze the situation, identify root causes, and implement the new process, you must continue to monitor the new process to assure that you maintain the improvements you’ve achieved. One statistical method you can use to do this is the process control chart.
Two other tools, the run chart and the histogram, are also used to monitor the process. These tools are easy to set up and maintain and don’t require the statistical calculations found in a control chart.
The run chart plots an individual metric over time and makes it easy to spot trends and patterns over time.
Here are some things to look for in a run chart that may indicate an unstable or problem process:
- Cluster: Several observations surrounding a certain value
- Mean shift: Several observations above or below the process average
- Oscillations: Observations that go up and down with recognizable frequency
- Trends: Several observations in a row that all go up or down
A histogram displays the frequency of different measurements. The histogram shows the distribution of the measurements and highlights measurements that are considered outliers from the rest. Histograms are useful to identify special cause variation.