Freeze the scheduled task list for one close process and a defined sequence of periods. Every scheduled task instance remains in the population, including tasks with no interruption. This prevents an event-only log from hiding the uninterrupted denominator.
For this study, an interruption begins when active work stops because of an unplanned request, access failure, unavailable record, system incident, or decision dependency. It ends when work resumes or the task moves to another declared state. Scheduled handoffs, planned review waits, weekends, and prerequisites already represented in the close calendar use separate status codes. The definitions must be fixed before anyone sees period comparisons.