Multiparty testing preorders

Variants of the must testing approach have been successfully applied in service oriented computing for analysing compliance between (contracts exposed by) clients and servers or, more generally, two peers. It has however argued that multiparty scenarios call permissive notions because partners usually do not full coordination capabilities. We propose new preorders, which are obtained by restricting set potential observers. For first preorder, called uncoordinated, we allow only sets parallel observers use different parts interface a given no possibility intercommunication. second individualistic, instead rely on perceive as silent all actions interest. uncoordinated preorder is coarser than classical finer individualistic one. also provide characterisation terms decorated traces both preorders: defined must-sets Mazurkiewicz while one described classes filtered contain designated visible must-sets.