The article concepts «business process» is spent, the process approach allowing is considered to consider organization activity as the connected system of business processes, each of which proceeds in interrelation with other business processes or an environment. The problem of the description of business processes, as the basic rising before the developer of model of business processes is revealed. The article contains the reasoning of descriptions of business processes on «accelerated» and «full» is offered for efficiency of definition of the purposes of working out of economicmathematical models that will allow concretizing a control system business by processes.