An undeveloped event is used if further resolution of that event does not improve the understanding of the problem or if further resolution is not necessary for proper evaluation of the fault tree. It is similar to a basic event, but is shown as a different symbol to signify that it could be developed further but that the analysis has not yet been done or need not be done for the sake of the analysis in question. Undeveloped events may changed to some other event type and broken down into associated gates and events if it is later deemed necessary.