The models and languages most widely used for distributed systems programming (such as ADA, CSP, and OCCAM) do not explicitly consider the process execution site, they assume a synchronous communication scheme of “rendezvous” style, and require that each process recognize the names of their interlocutors. JOYCE+ is a modification of the JOYCE language defined by Brinch Hansen [Brinch 87, Brinch 89]. In the JOYCE+ model each process is executed in a specific site, it is assumed that the communication between processes at the same site is much more faster than between processes at different sites, and it is also assumed that the communication between processes is not always reliable. For this multi-site environment an asynchronous communication scheme is considered, eliminating waiting states for a process that sends a message to another process. Furthermore, modelling communication between processes through “channel” objects, the spaces for process names become independents.