Widely used mathematical models begin to penetrate in public management system. Several decades ago methods of operational calculus, decision-making under condition of uncertainty and other static theories were used. Nowadays, more and more attention is paid to dynamic systems, used as basic for various forecasting approaches. In governmental planning significant roles belong to aims and targets expressed through slogans and proclamations without numerical backing. At the same time statistical services regularly collect huge amounts of different indices. Then these indices are somehow combined into aggregates. Thus there pyramids appear consisting of aggregates, expressing public management aims and targets. However the problem of target 'digitization' has more than one solution. On solving this problem some experts are involved, who are subjective, and also priorities on which aggregates are based on transform if political, economical or social situation changes. Thereby the indices pyramids are time-dependent, which makes comparison and other analysis rather complicated. Suggested in this paper method allows to choose a 'natural' index instead of aggregate, but to choose with preserving the experts priorities. This method is based on defining a collation metric for time series with 'natural' and aggregate indices (gained with experts' participation). A comparison of different metrics for real numerical data is made.