The paper deals with the problem of unified description of decision making processes. Firstly, a terminology of decision cycles serving to describe such processes is introduced and explained. This presentation addresses earlier results presented in the literature. Using the terminology introduced, some general propositions on convergence of unified decision processes are shown. Next, three diverse instances of unified decision processes are presented to illustrate general findings. This part of presentation includes examples of decision making under uncertainty, deterministic case and interactive multiple criteria processes.