This paper examines the effects of changes in information-processing technology on the efficient organizational forms of data-processing in decision-making systems. Data-processing is modelled in the framework of the dynamic parallel processing model of associative computation with an endogenous set-up costs of the processors. In such a model, the conditions for efficient organization of information-processing are defined and the architecture of the efficient structures is considered. It is shown that decreasing returns to scale of the function describing data- processing technology and the information overload of the system are necessary and sufficient conditions for the hierarchical information- processing, respectively. Moreover, the size of the efficient structures is determined exclusively by their information workload and the current state of information-processing technology.