Follow these steps as a guideline to help with your next process loss review
1. Begin with some reading
Paul Barringer developed the Weibull Process method and his paper "Weibull Analysis of Production Data" has great information on the application of this method.
2. Data
Get a data set of daily production data over a 12 month period.
3. Perform a Weibull Analysis
Input the daily production data to a Weibull data analysis package. You can choose from Isograph’s Availability Workbench™ (AWB) Process module, Wes Fulton’s WinSmith, or Reliasoft's Weibull++. AWB is an integrated package which has modules including AvSim+ for System Availability, RCMCost for optimizing maintenance decisions, Life Cycle Costing simulation and Process Reliability. Whereas the other packages are stand-alone and require information to be transferred. The Process Reliability module has been set up so that the graphs are preconfigured and the production beta, reliability of the process, and lost production can all easily be seen.
4. Determine Production Beta
Determine the Production Beta, the Reliability of the Process, establish the name plate and determine the production losses due to production variation or special cause losses.
5. Focus Efforts
Focus improvement efforts on “where the losses are greatest” – process variation or special cause.
6. Data Analysis
Analyze the data and choose an improvement method. Use Root Cause Analysis (RCA) to address special causes, use Reliability Centered Maintenance (RCM) to improve maintenance plans, use System Analysis to address plant configuration, logistics and equipment design.
7. Model Improvements
Model improvements in a Reliability Block Diagram such as the AvSim+ Module of AWB (or alternate such Raptor, Maros, etc).
8. Determine System Availability
Use the System Availability model to generate predicted production data.
9. Cost Benefit Analysis
Use Cost Benefit analysis to show the reduction in production losses (gains) versus cost.
10. Create Business Case
Share your business case with your production manager
11. Continue to Monitor
Run production data each quarter and monitor losses and their nature.
