One of the sections of the theory of multifactorial experiment is presented - the methodology of planning an experiment under conditions of heterogeneity. Detailed planning methods are described to exclude and evaluate the influence of discrete drift on the use of combinatorial schemes such as Latin, [Hyper-Recko-Danish Squares] rectangles and cubes, BIB and PBIB diagram, Complex non-symmetrical plans , and also questions of use of combinatorial schemes for construction of plans of the second order and consecutive screening experiment. The methods of planning in conditions of continuous drift are given, All the methods of planning under consideration are special techniques with a restriction on randomization of the conditions of the experiment. The presentation is conducted in a prescription plan and is illustrated by numerous examples brought to the calculations. The book is of interest to specialists in many branches of science - chemists, physicists, biologists, automation specialists - all those who are associated with the planning of the experiment.