Distributed testing of multi input/output transition system

This paper develops the refusal testing theory of multi input/output transition system (MIOTS) in the direction of distributed testing where multiple testers are involved Centralized MIOTS testing (where only one tester is used) can be based on two types of observers: the singular-observer and the all-observer For each of the two cases, we define a test architecture and propose a method to distribute a centralized test case onto a set of distributed testers. The singular observer can only observe one channel at a time, and the distribution of singular-observer tests is indeed a projection of the global test tree on local testers with proper handover messages. The all-observer can observe all the output channels simultaneously, and distributing all-observer tests requires a mechanism for solving output contentions and synchronizing local testers. Examples are used to illustrate these methods.