A GUIDE FOR EXPERIMENTAL DESIGN UNDER THE PERSPECTIVE OF THE BASIC PRINCIPLES OF EXPERIMENTATION.
DOE; analysis of experiment; randomization; block; replication; operational restriction.
Considering the high levels of competitiveness faced by organizations, the area of design and analysis of experiments plays an important role, since it consists of a fundamental statistical technique with several contributions, such as in the process of developing new products, increasing efficiency, reducing variability and costs involved, as well as a considerable gain in data analysis time. This work aims to develop a procedure to guide the design and analysis of experiment. To do so, the main concepts on this area of study are used as well as the understanding of the basic principles of experimentation (randomization, replication and blocking). In addition, as an illustration of the use of the guide, is applied to identify an efficient and operationally feasible experimental design at a water treatment plant (WTP). Also, we propose a method of analysis according to the execution of the experiment. This experiment considers four factors (pH, dose, recirculation ratio and flocculation time) and six quality characteristics (pH, turbidity, color, suspended solids, total solids and alkalinity), with 36 different configurations (32×22), two replicas each, totaling 72 tests. The present study contributes to the literature in three ways. First, with the development of the guide for studies in the area of experimental design, because this gap is identified in the current academic literature. Second, the present work seeks to disseminate the importance of design experiments for different areas of study, considering that experimental design helps to reduce costs, optimize time and resources. And third, with a systematic review of the literature on the applications of factorial design in the area of environmental engineering and with the design and analysis of an environmental experiment.