Safety in microcomputer-based control and monitoring systems. The conditions for assessing safety in microcomputer-based control and monitoring systems for safety-related applications in automatic production systems are discussed in this report. Compared with relay technique and conventional electronics, the complexity and the frequent changes of states in microcomputer-circuits, require a radically new approach with respect to conceptions, measures, requirements and assessment methods. To identify and assess the effects of all imagible fault modes in microcomputer components is not possible. Furthermore, the technique introduces a new category of faults, systematic software faults. It has not been possible to exclude the microcomputer technique from safety-related applications. The technique does even provide benefits compared with conventional electronics e.g. regarding automatic fault monitoring. It has been important also to consider the current "state of art" in the area. Therefore, the principal design of a number of existing microcomputer-based and safety-related products is described. A strategy is outlined for further activities to create requirement levels and assessment methods. The importance of ambiguous, demarcated and concrete methods is emphasized.