Background: We have N Parallel Multi Instance tasks, and if any of them fail, all the remaining N-1 tasks must be canceled. We thought we could invert the logic for each of these tasks and then use a simple XOR merge, but the XOR merge would not cancel the evaluation of the remaining N-1 tasks.
A multi-instance activity ends when all instances are finished. However, it is possible to specify an expression that is evaluated every time one instance ends. When this expression evaluates to true, all remaining instances are destroyed and the multi-instance activity ends, continuing the process. Such an expression must be defined in the completionCondition child element.