Simulation of system behaviour using qualitative vectors

In the absence of complete quantitative knowledge about the structure of physical, economic or social system one can use qualitative methods taken from the field of Artificial Intelligence. The idea of qualitative vectors is an important extension to the use of scalar qualitative values represented by symbols drawn from the set Q = {−, 0, +}. The qualitative vector consists of three elements: the qualitative value of the variable and its two successive derivatives. The qualitative mathematics of the scalar case has also been extended to support such operations as vector integration and differentiation. The simulation process based on a model expressed in terms of qualitative vectors produces a set of vectors’ sequences for each of the model variables. Each of these sequences represents a distinct behaviour of the system being simulated.