The three report families
- TAC usage reports: Teams-specific (user activity, device usage, apps, PSTN/minutes) — operational grain.
- M365 admin usage: cross-workload rollups — the exec deck's source.
- Graph reports API (
/reports/getTeamsUserActivity...et al.): the same data as CSV/JSON for YOUR pipelines — serv365's Pulse concept consumes exactly this family.
Ground rules that keep credibility: ~24-48h lag (never present 'today'); activity != value (messages-sent measures typing, not outcomes — pair with outcome metrics before drawing conclusions); period windows differ per report (7/28/90-day) — label them.
The pseudonymisation switch
M365 admin center privacy setting can replace user identities in ALL these reports with pseudonyms — org-wide, works-council-relevant, and the silent reason a per-user adoption report suddenly shows hashes. Know your tenant's stance (it's a setting; it's in audit when flipped) and design reports to their privacy posture, not against it.
Reports that earn their keep
- Licence reclamation: assigned-but-inactive (licence details vs activity) — the report that funds itself.
- Capacity truthing: device usage + meeting minutes per site against the network module's models.
- Adoption curves post-rollout: app usage before/after a setup-policy pin (the apps module's rollouts, measured).
- PSTN cost lines: minutes by user/destination (voice modules) — finance's standing ask, automatable via the reports API.
What to watch (proofs)
- The lag, measured once: an action you performed vs its report appearance — your tenant's real freshness, quoted in every deck footnote.
- The privacy stance: the pseudonymisation setting's current value + its audit history — before someone escalates 'broken reports'.
- Pipeline health (if you automate): scheduled Graph report pulls' success + row-count trend — a feed that silently flatlines poisons every downstream chart.
- One reconciliation: TAC report vs Graph CSV for the same period — they should agree; understanding any variance (windows, timezone) once saves every future argument.