Partial and complete local diagnosis in computer systems with circulant structure

System diagnosis at multiple faults of multiplicity not greater than t is considered. The conditions when the state of each system module is only determined by the testing rusults of the physically connected modules (self-determination conditions) are analysed. The diagnosability conditions are established for the case when the self-determination conditions are not satisfied for any module. A new class of locally (t(r) /t)-diagnosable systems is introduced, where t is the fault multiplicity and t(r) is the multiplicity of faults at which the states of all system modules can be determined correctly and completely. The values of t(r) are estimated. It is shown that the local t-diagnosability can be achieved by the system test redundancy.