Segregation of trace elements on a surface, at grain boundaries or more generally in any interface can have important consequences: adhesion of thin films, catalytic activity, embrittlement of steels by P or of nickel alloys by S, reinforcement of nickel alloys by B, etc. Segregation kinetics can be simulated by a finite element (FE) approach, by implementing the Darken-Du Plessis equation at the interface and Fick's diffusion laws in the bulk. It is then possible to simulate segregation kinetics in non-isothermal conditions, and to couple segregation and macroscopic heat transfer calculations. A previously developed model is here adapted to the case of complex interfacial segregation phenomena: (i) segregation of a single species with a solute-solute or solute-solvent interaction, (ii) co-segregation of two species with a site competition in the interface, and (iii) segregation of a single species at an interface between two phases. Results are compared with available experimental data.