Abstract: Memory fault models have always been considered not to change with time. Therefore, tests constructed to detect sensitized faults need not take into consideration the time period between sensitizing and detecting the fault. In this paper, a new class of memory fault models is presented, where the time between sensitizing and detection should be considered. The paper also presents fault analysis results, based on defect injection and simulation, where transient faults have been observed. The impact of transient faults on testing is discussed and new detection conditions, in combination with a test, are given.