This paper is a contribution to material behaviour modelling. Total strain is decomposed into elastoplastic and viscoplastic strains. Both parts are analysed separately and put together by the principle of superposition. The spring-slider model controlled by either stress or strain enables elastoplasticity modelling under constant or variable temperature with the Prandtl operators. Viscoplasticity is taken into account, if temperature exceeds creep temperature, by adding a nonlinear damper to existing spring-slider models, otherwise just elastoplasticity is considered. The material parameters result from isothermal strain-controlled low cycle fatigue(LCF) tests. Hysteresis loops are assumed to be stabilized. The high speed of computation that is characteristic of Masing and memory rules is retained. Solving of differential equations is not required. The model developed so far is uniaxial, but a multiaxial extension is possible.