In manufacturing processes, some process factors are involved with two or three previous processes conditions. Current research has shown that strip-plot structure is an interestingly proposed for the experimental design in multi-stage processes. Thus, this research is addressed to utilize the strip-plot structure in three multi-stage processes. The experimental design involves first order and second-order, Central Composite Design (CCD), within strip-strip-plot structure. D-optimal criteria are calculated to estimate the efficiency of the design. The expected response model is composed of main, quadratic, within-stage interaction and cross-stage interaction effects. Two food manufacturing processes are chosen to prove the multistage design of experiments. Their multiple regression models are calculated and optimized by standard software. The practical confirmation results are in a favor of the approach.
