What?
To “centerline” a process, you must perform these four steps:
- Identify the important process factors or “variables” (Analysis, Comparator)
- Determine the best settings and ranges for all of the important variables – by grade or product if multiple products are being produced (Dashboard, SPC, Chart, Production Standards)
- Ensure that the centerline settings are always used during production (Live and Report)
- Iterate the process to further improve control and focus on the right parameters
Why?
To ensure product consistency, many manufacturers strive to ensure that the process runs the same way all of the time. This is where centerlining can help. Benefits can include improved product quality, increased production, reduced downtime, reduced off-quality product, reduced waste, reduced costs, and/or increased profits. Centerlining can also help in the detection of process upsets, which allows corrective or preventative actions to be taken.
How do you know if your process is adequately stable? Use an SPC Report or Dashboard on your KPIs. If there are deviations outside of 3 sigma then you may have special cause variation. Many of those special causes can be reduced through the use of Braincube centerlining tools.
Often a plant that just got Braincube will work on centerlining for 6 months to start. It's a simple way to get the operations team comfortable with Braincube tools while also ensure that anything that might affect viability of future rules are controlled.
Example: Energy consumption study
Example
1. Identify the important process factors or “variables” (Analysis, Comparator)
- Choose the Process Area where Braincube Live will be displayed
TIP #1
Start with the product you run most often first and the most upstream product section. Stability downstream cannot correct for upstream variability. - Create a Data Group for that Process Area including key input variables and key process indicators important to the operators
TIP #2 - If you need inspiration, run a Comparator to see what was different between a time of good and bad KPI performance. Of the variables that experienced changed, which ones can you control? Include those in the data group.
2. Determine the best settings and ranges for all of the important variables – by grade or product if multiple products are being produced (Dashboard, SPC, Chart)
- Use SPC/Dashboards/Charts of your KPIs for the process area to identify a period of best operation
- In All Charts, select this period of good operation
- Select your Data Group using All Charts to visualize input variable performance during that period of best operation
- Turn Off Auto Zoom
- Apply necessary Filters to “scrub” or clean data to a period of time where the Process Outputs were stable and desirable
- For example, filter by Grade to create Specification for specific grade(s)
- Open any chart and, using “Select Functions”, and apply Specifications
- Using “Select Functions”, apply a confidence interval at 3 sigma
- Once satisfied with filters, Open the Filter, add End DateTime as a filter condition and select the time period that you used in All Charts.
- Save the New Filter with proper naming convention, ex., “Centerline | ProdName”
3. Ensure that the centerlined settings are always used during production (Live and Report)
- From the Production Standard module, select the +/- button to create a new specification
- Name the specification ex., “Centerline | ProdName”
- Select the Centerline | ProdName filter in the Conditions section
- Select the Data Group to import your variables (the yellow and red limits will populate at 2 and 3 standard deviations, respectively)
- Validate the variables and their limits and edit, if necessary
- Once satisfied with limits, uncheck the DateTime filter. Keep any filter conditions that will be needed for filtering gauges in Braincube Live
- Check the box to activate Braincube Live
- Save the specification
- Create and Configure Braincube Live Display (Admins only) 10. Select drop-down by clicking on Username in top-right of page 12. Select Configure 13. Find and select Live Configuration in the header of the page 14. Add Live using +/- button in the top-left, or, select the desired BC Live Display if it already exists 15. Select Variable Location(s) to display on Braincube Live Display 16. Select other desired features for Live Display such as Display Options
TIP #3
Centerlining is a never-ending process. The following circumstances may indicate a need to adjust your centerlining rule:
- High effort % consistently - Congratulations, you've achieved improved stability. You may be able to further refine the specified ranges to further reduce process variation
- Low effort % consistently - ask yourself these questions:
- Is the target operational range feasible in current conditions? If the rule is feasible, try to uncover why it's not being respected and address that situation. Remember, you have operated in this range in the past, it may be best to really dig into why the team isn't able to achieve the same way of running again.
- Has the low effort % negatively impacted performance? If not you may be able to widen ranges.