Dear all, I would like to characterize the behavior of a certain product over its lifetime. The purpose is to compare the behavior of experimental versions of the product vs. a baseline version. It's known that the behavior of the product follows a roughly trapezoidal pattern: start-up effect where the performance ramps up, then steady state performance, finally a degradation at the end of the life. A sensor captures the performance every two minutes. Is anyone aware of a package that can be used for such a cradle-to-grave comparison? This is not quite survival analyses, because I'm interested in more than just 'length of life'. Interest is in 'length of ramp-up', 'length & amplitude of steady-state' and 'length of degradation'. I've considered Time Series with seasonality or Fourier analyses to deconstruct the behavior into periodic component. However, the I'm not aware of TS or Fourier comparisons for contrasting two populations. Such comparisons are probably common in image analysis, but that's a foreign field to me. Thank you, Paul Paul Prew Ecolab R&D Eagan, MN CONFIDENTIALITY NOTICE: \ This e-mail communication an...{{dropped:11}}