Differential equations with discontinuous right hand sides crop up when modelling switches or relays in control systems. In order to deal with these discontinuities we need to generalise the concept of solution so that the differential equations are satisfied almost everywhere. Differential inclusions incorporate the discontinuities of the differential equation in order to obtain a well defined solution. In this talk we focus on the mathematical complications that arise with the discontinuous right hand side and how they are overcome using differential inclusions.