Beschreibung:
As information technology (IT) administration becomes increasingly complex, workflow technologies are gaining popularity for IT automation. Writing correct workflow programs is notoriously difficult. Although static analysis tools are available, fixing defects remains manual and error-prone. This paper applies discrete control theory to IT automation workflows. Discrete control detects flaws in workflows just as static analysis does, and more importantly it also allows safe execution of flawed workflows by dynamically avoiding run-time failures. Our approach can guarantee compliance with certain requirements and can partially decouple requirements from software, reducing the need to modify the latter if the former change. We have implemented a discrete control module for a real IT automation system. Experiments with workflows from a real production system and with randomly generated workflows show that our approach scales to workflows of practical size.