Design of Experiments (DOE) is used to analyze a process to determine which process inputs have the greatest impact on the process. The process inputs, referred to as factors (e.g., temperature, quantity, etc.), have different levels. DOE allows a comparison of how different levels for the factors impact the process output or response. DOE uses randomization and replication to improve the results of the experiment. A concept called blocking allows variable factors to be removed from the experiment (e.g., differences between workers on a first shift and a second shift). Experiments are then created using full or fractional factorial designs.