By defining a stage that contained only CapEx-eligible activity, and isolating it from all other stages, CFOs could prove that they had exercised due diligence when listing an expenditure as a capital expense.
The good news is that everything you need to do to assure the CFO that the project will pass an audit takes place outside of the actual development process. If you can assure the C-suite that their needs will be met, they should be amenable to a hybrid methodology in which financial concerns are handled via Waterfall in the planning stage and development is done in an Agile framework:
For example, alongside a baseline estimate, you might provide a cheaper option that would be feasible if cost-saving conditions are met, like doing data migration via manual entry, or a more expensive option if extra features are included, like a mobile app
if you provide project budget reports or updates, make sure your line item titles and descriptions exactly match the ones you used when the budget was first approved. If the approved budget refers to “Epic: Authentication UI,” then that’s what you should put on your report—not “Epic Login Screen”