What is a Sensitivity Analysis?
Why Use a Sensitivity Analysis?
Sensitivity Analysis in OLI Flowsheet: ESP
Objective
Sensitivity analysis in OLI Flowsheet: ESP is a powerful tool that allows users to explore how changes in key input variables affect the performance or outcomes of a process simulation. Whether you're designing a process, optimizing an existing one, or conducting a feasibility study, a sensitivity analysis provides valuable insights into system behavior under varying conditions.
Disclaimer: The user interface, calculations, and results displayed in this article are from OLI Flowsheet: ESP Version 12.0.0. Other software versions may appear different or present slightly distinct results due to continual developments to the software and thermodynamic databanks.
What is a Sensitivity Analysis?
In process modeling, a sensitivity analysis involves systematically changing one or more input variables—such as temperature, pressure, or flow rates—to evaluate their effect on one or more output variables. This approach helps identify critical parameters that influence process performance and can guide design decisions, operational strategies, or risk assessments.
Why Use a Sensitivity Analysis?
There are several benefits to performing sensitivity analysis in Flowsheet: ESP:
- Understand system behavior: See how small or large changes in input parameters affect outputs.
- Identify key drivers: Determine which parameters have the most influence on your simulation results.
- Support optimization: Use results to focus your efforts on impactful areas for process improvement.
- Perform “what-if” analyses: Assess multiple scenarios quickly without building separate cases for each.
Sensitivity Analysis in OLI Flowsheet: ESP
OLI Flowsheet: ESP offers a dedicated Sensitivity Analysis tool that enables the setup and visualization of analysis runs. Users can specify one or more independent variables and select the dependent variables they wish to track. The tool automatically runs multiple simulations over the specified range and aggregates the results for easy comparison.
Key features include:
- Adjust Block parameters: A sensitivity analysis can be performed by adjusting a Block parameter in the model. This would constitute the independent variable, also known as a "sensitivity parameter" in the software.
- Graphical and tabular output: Easily interpret the results through plots and tables.
- Add several plots: Users can add more than one Sensitivity Plot, which is helpful to separately analyze the results from different sensitivity analyses in a single run.
- Export results: Save the tabular data to a CSV file or save the plot to a JPEG file.
- Integration with the Calculator Functionality: Track how a calculated user-specified variable in a Calculator Block changes concerning the independent variable(s). For more information on the Calculator Functionality, please see our OLI Flowsheet Calculator Object.
- Enable multiple sensitivity analyses in a single run.
- Disable specific sensitivity analyses as needed.
Note: Sensitivity Analysis and Optimizer cannot be enabled at the same time.
Watch the Video Tutorial
For a guided walkthrough, watch our video tutorial below. The video closely matches the Sensitivity Analysis demonstration in the Calculator Functionality article, with some additional information. It covers:
- Setting up a sensitivity analysis from start to finish
- How to add a New Monitored Variable for Composition-based Stream analysis
- Choosing an example independent variable (e.g., Manipulator Block Flow Factor) and analyzing an output variable (e.g., the output from a Calculator Block)
- Interpreting the results with the built-in Plot tool
Video Duration: ~2.5 minutes
Tip: Use full screen mode and adjust playback speed if needed.
Conclusion
Sensitivity analysis is an essential capability in OLI Flowsheet: ESP for uncovering how process variations impact system behavior.
Need more help? Reach out to OLI Support at support.olisystems.com or browse related topics in the Support Center.