An approach to verifying and debugging simulation models governed by ordinary differential equations: Part 1. Methodology for residual generation

For dynamic simulations to be credible, veri cation of the computer code must be an integral part of the modelling process. This two-part paper describes a novel approach to veri cation through program testing and debugging. In Part 1, a methodology is presented for detecting and isolating coding errors using back-to-back testing. Residuals are generated by comparing the output of two independent implementations, in response to identical inputs. The key feature of the methodology is that a specially modi ed observer is created using one of the implementations, so as to impose an error-dependent structure on these residuals. Each error can be associated with a xed and known subspace, permitting errors to be isolated to speci c equations in the code. It is shown that the geometric properties extend to multiple errors in either one of the two implementations