Sensitivity Analysis add-in for Microsoft Excel 97, 98, 2000, and 2001 for Windows. The toolkit is intended for the analysts in economy, science and engineering. The product allows to perform the sensitivity analysis of output parameters of a model for want of specific modification of input parameters. The outcomes of the analysis are illustrated as the charts (such as Simple Plot, Tornado, Spider) and tables, and it is possible to export it to the MS Excel (charts and tables) as a separate worksheet. The product has the convenient interface of a visual selection and adjustment of significant input parameters in models for optimization of target (researched) parameters. Allows to solve economic, scientific and technical problems connected to a research of a dynamic behaviour of models, prediction of significances of target parameters dependent on several input data