Having K parameters to be analysed, the first θ i is changed by small δ θ ** and then fixed, while the remaining θ j =i are optimised. The parameter θ i is changed again by δ θ and the θ i = j parameters are estimated anew. This is to be repeated as long as SSE(θ ) is smaller than SSE max and therefore H 0 is not rejected. This procedure is performed for all parameters in the same manner and all θ that satisfy equation 35 define the confidence region. In SupraFit some additional parameters are introduced to control the procedure, like the maximum number of steps, the step size and the convergence threshold for the sum of squares. A comprehensive list is given in the manual of SupraFit and a short description of each parameter is shown as tooltip in the SupraFit program. Obtained results are graphically presented as shown in Fig. , where one parameter was analysed. The dash-dotted line indicates the estimated value θi and the solid line indicates the obtained sum of squares for each variation of θ i while θ i = j are being optimised. Only values where the error is smaller than the threshold are plotted. The Grid Search is parallelised, so that for each parameter θ i two processes independently evaluate either θ i,-or θ i,+ .