In order to yield an expression for the probability of breaching, in this desk study the mechanism that play a role in the initiation of breaching of dunes are described and preliminary quantified. In addition a pragmatic description for the assessment of the combined probability of breaching is elaborated. From this it was concluded that although the transition between negligible probability and assured failure is relatively gradual, the present approach using the so-called 'grensprofiel' seems adequate.