Growth, Life Cycle and Dynamic Modelling

Growth and diffusion processes have received great interest from investigators in many disciplines, such as Biology, Demography or Economics. These processes are usually analyzed by means of sigmoidal curves that formalize the well-known theory of the life cycle. The characteristic stages in the biological life cycle of an organism are widely applicable to technology progress, sales of a new product or the evolution of economic sectors. In this paper a mathematical characterization of sigmoidal growth is presented that gives rise to a general methodology for modelling such processes, additionally allowing to establish a qualitative equivalence among sigmoidal growth-type phenomena.