Model each year as its own line item with explicit start and end dates, and treat co-terming as a first-class scenario rather than an exception. Amendments and co-terming are where quote-to-cash complexity goes exponential, so they must be scoped before tool selection, not after.
Capture how the business wants to amend and co-term ideally while staying tool-agnostic, then check whether the chosen platform can actually do it. Discovering a co-term limitation during build is the single most common cause of CPQ scope overrun.
Every claim above comes from work LeanScale published. These are the sources.