User stories describe small pieces of work. A product spec (sometimes called a product requirements document or functional specification) puts the bigger picture in one place: why this feature exists, who it is for, what it must do and how you will know it worked. Analyst and product roles in Ghana often list functional specifications and product documentation as core duties.
A good spec lets designers and engineers work without waiting for you to answer the same questions repeatedly.
What goes in a short spec
Keep it to one or two pages where possible. A useful structure:
- Problem. What is wrong today, with evidence from interviews, data or support.
- Users. Who this is for, and who it is not for.
- Goal and success measure. What will change if this works, stated as something you can measure.
- Requirements. The user stories and key functional and non functional requirements, with acceptance criteria or links to them.
- Out of scope. What you are deliberately not doing this time. This section prevents many arguments.
- Risks and open questions. What you are unsure about and how you plan to find out.
- Rough flow or sketch. A simple diagram or wireframe photo if it helps.