Relationship economics only work when tiers update as matters close - and clients can see progress without a custom report.
Volume tiers only create value when they stay accurate. Rebuilding YTD spend in a spreadsheet every quarter is how discounts drift from the relationship you promised the client.
Automatic tier tracking updates as matters close. Clients see savings and progress in the portal. Business development can talk about distance-to-next-tier with numbers that match the books.
That is not a reporting feature. It is relationship pricing as a living system.