What does it mean that integration across operational systems?

Your operational systems should feed into each other seamlessly.

Example: You have a task management system, a calendar, a note-taking tool, and a weekly review process. Each one works well in isolation. Your tasks are captured reliably. Your calendar is organized. Your notes are thorough. Your review happens every Sunday. But your task system does not feed your calendar — you manually re-enter deadlines. Your notes from meetings do not generate tasks — action items sit buried in paragraphs you never revisit. Your weekly review does not update your priorities — you read your journal, nod thoughtfully, then start Monday with the same default list you had last Monday. Each system is a closed loop. Nothing flows between them. The result is that you do the work of maintaining four systems but get the benefit of one, because the integration layer — the handoffs that would make the whole greater than the sum of its parts — does not exist.

Try this: Draw your operational systems as nodes on a page — task management, calendar, notes, review, communication, file storage, reference material, whatever you actively use. Now draw arrows between every pair where the output of one should become the input of another. For each arrow, write a one-word label: 'active' if the handoff actually happens reliably, 'manual' if it happens but requires you to remember and do it by hand, or 'broken' if it rarely or never happens. Count your broken arrows. Pick the three that would have the highest impact if fixed, and for each one, write a single sentence describing the specific handoff: 'Output X from System A should become Input Y in System B.' These three sentences are your integration debt backlog.