The anisochronic observers result from a functional extension of the classical state space bringing a significantly reduced number of needed state variables, as compared with the standard approach. The anisochronic state variables can be selected as measurable outputs in most cases and their availability provides significant advantage in process monitoring. Observability condition is presented for anisochronic process models with arbitrary sort of delays. Since hereditary systems are considered a typical result of control system integration the issue of decomposition on separate units is followed in observer design. As a special aim, the observer design delay cancellation in the observation process is solved using a functional extension of Ackermann's formula for this purpose.