With the ABB Ability™ Knowledge Manager's statistical production analysis, trend functions such as X, EWMA and CUSUM charts are selected to match specific requirements of manufacturing processes. X-Y graphs show the correlation be-tween two variables, with compensation of time delay. Histograms allow for readable statistics of run-time quality measurements.
In SPC, quality is emphasized as a process characteristic. If the process is controlled and improved, product quality will be automatically maximized. Product specifications, therefore, are normally excluded from quality improvement activities until the process is optimized. Once the process is stable, product specifications are compared with process control limits to determine if the process can manufacture the product to those specifications.
- X charts (Shewhart)
- EWMA charts
- CUSUM charts
- Multivariable X-Y correlation graphs