Explain what people need to do
Start with users and tasks. A request for a portal becomes more useful when it explains who signs in, which records they should see and what action they need to complete. Include the situations that should require an approval or a different level of access.
Share the current workflow, even if it is informal. Existing forms, spreadsheets and process notes can help explain the requirement without a long technical specification.
Separate essential features from later ideas
Identify what a first release must do and what can wait. Dependencies matter: a feature that needs an unavailable integration may need further assessment before it can be included in the scope.
Agree how each essential function will be accepted. For example, define which users can update a request and what should happen when information is missing.
Plan for the work after launch
Launch is a milestone, not the whole ownership arrangement. Clarify documentation, training or handover needs, hosting, third party costs and how further changes will be handled.
Source code ownership, intellectual property, licensing and maintenance belong in the project agreement. Making these decisions explicit helps both parties understand what the project includes and what needs a separate scope.