Considering the fact that test response observation and test application only use a fraction of test time
a test subsession partitioning scheme is presented.Some further sources of the test scheduling problem can be used.Subcircuits in conflict in the process of test are only partially in conflict now.A new test scheduling algorthm is proposed after the test subsession partitioning scheme has been combined.The effectiveness to search the test scheduling solution is improved greatly by using the previous conflict information.