Within Stateflow®, the choice of whether to use a flow chart or a state chart to model a given portion of the control algorithm functionality should be driven by the nature of the behavior being modeled.
If the primary nature of the function segment is to calculate modes of operation or discrete-valued states, use state charts. Some examples are:
Diagnostic models with pass, fail, abort, and conflict states
Model that calculates different modes of operation for a control algorithm
If the primary nature of the function segment involves if-then-else statements, use flow charts or truth tables.
If the primary nature of a function segment is to calculate modes or states, but if-then-else statements are required, add a flow chart to a state within the state chart. (See Flow Chart Patterns.)