Sudden change in a model of small firm growth

A catastrophe theory model of small firm growth allows for an abrupt change in small firm size. The model permits only smooth changes in the endogenous independent variables, turnover and profitability, yet allows sudden changes in the level of assets, the size variable. But not all growth paths suggested by the mathematics are likely to be met in the real world. Nevertheless, there are feasible phases of steady growth as well as feasible phases during which jumps occur.