Low bug count

Using statecharts has the potential to dramatically lower the bug count of software. Ian Horrocks found a reduction in bugs of between 80 and 90 percent when employing statecharts, and that the remaining bugs were seldom in the statechart itself.


In one of the few studies in this area, Ian Horrocks found that the bug count of statechart based code was significantly lower than traditional code:

The bug rates were significantly lower in modules designed with statecharts than in modules developed with a bottom-up approach. The number of bugs found during the system testing of a statechart module was between 10 and 20% of the number of bugs found in similar modules constructed using the bottom-up approach. Significantly, most of the bugs found in statechart modules were related to errors in the actions associated with events or errors in the attributes of screen items, rather than errors in the design of the statechart itself.

Ian Horrocks, Constructing the UI in Statecharts, page 200