The first question is what the work should make possible: more capacity, fewer preventable errors, a usable new product, or a clearer path from interest to inquiry. The plan should connect the deliverable to that purpose.
Establish the Starting Point
Use a representative task, current workflow, or existing site. Record the time, failure, or missing capability that makes a change worth considering.
Choose a Complete First Phase
Keep the input, essential rules, usable output, and review path together. Separate later features and dependencies so you can assess the first investment on its own.
Agree on the Evidence
Specify what will be tried, what counts as accepted, and what you will compare. Include operating costs and upkeep when judging the benefit.
A test result can establish that a feature works. Business value depends on how it performs in your setting. Revenue, savings, and return are project-specific, not promised figures.