1. GoldSim Technology Group LLC, 2007 Slide 1 GoldSim User Conference San Francisco, CA October 25-26, 2007 GoldSim Tutorial and Discussion: Techniques for Testing, Ensuring Quality and Validating GoldSim Models

2. GoldSim Technology Group LLC, 2007 Slide 2 Overview Best practices for building models that are not error-prone Testing and verifying models –Verification tests whether the model does what you think it does e.g., it accurately solves the equations Validating models –Validation tests whether the model is an appropriate representation of reality It solves the right equation Most of this is common sense

3. GoldSim Technology Group LLC, 2007 Slide 3 Best Practices for Building Models that are Not Error-Prone Document your assumptions in the model as you build your model –Notes, Text boxes –Use descriptive names

4. GoldSim Technology Group LLC, 2007 Slide 4

5. GoldSim Technology Group LLC, 2007 Slide 5 Best Practices for Building Models that are Not Error-Prone Document your assumptions in the model as you build your model –Notes, Text boxes –Use descriptive names Break complex calculations into separate elements –Do no bury details in input fields

6. GoldSim Technology Group LLC, 2007 Slide 6

7. GoldSim Technology Group LLC, 2007 Slide 7

8. GoldSim Technology Group LLC, 2007 Slide 8 Best Practices for Building Models that are Not Error-Prone Document your assumptions in the model as you build your model –Notes, Text boxes –Use descriptive names Break complex calculations into separate elements –Do no bury details in input fields Use arrays (vectors or matrices) or cloned Containers for identical parallel calculations

9. GoldSim Technology Group LLC, 2007 Slide 9 Using Cloned Containers A AB X = f(A,B) B Clone1 Clone2 Localized

10. GoldSim Technology Group LLC, 2007 Slide 10 Best Practices for Building Models that are Not Error-Prone Don’t put unit conversions into your model

11. GoldSim Technology Group LLC, 2007 Slide 11

12. GoldSim Technology Group LLC, 2007 Slide 12 Best Practices for Building Models that are Not Error-Prone Don’t put unit conversions into your model Don’t use an equality test

13. GoldSim Technology Group LLC, 2007 Slide 13

14. GoldSim Technology Group LLC, 2007 Slide 14 Best Practices for Building Models that are Not Error-Prone Don’t put unit conversions into your model Don’t use an equality test Any other suggestions or comments?

15. GoldSim Technology Group LLC, 2007 Slide 15 Testing and Verifying Models To the extent possible, break your model into modules (e.g., functions or subroutines) that can be testing separately –Test over a range of variables –Compare to independent calculations (spreadsheet, analytical solution) Use Interrupt elements to check for invalid behavior and bad logic

16. GoldSim Technology Group LLC, 2007 Slide 16

17. GoldSim Technology Group LLC, 2007 Slide 17 Testing and Verifying Models To the extent possible, break your model into modules (e.g., functions or subroutines) that can be testing separately –Test over a range of variables –Compare to independent calculations (spreadsheet, analytical solution) Use Interrupt elements to check for invalid behavior and bad logic Other ideas or suggestions?

18. GoldSim Technology Group LLC, 2007 Slide 18 Validating Models If possible, compare predicted results to historical observations Can use GoldSim’s Optimization features to calibrate predicted results to observed results (typically entered in a Time Series)

19. GoldSim Technology Group LLC, 2007 Slide 19

20. GoldSim Technology Group LLC, 2007 Slide 20 Final Words The time spent ensuring quality will be repaid many times over You must be thinking about this from the beginning of the project – don’t wait until the end