Short answer
A good specification describes the business goal, user roles, processes step by step, the main features with priorities, integrations, data and non-functional requirements (security, speed, accessibility). It doesn’t need to be technical — what matters more is to describe clearly how you work and what needs solving.
What to include
- Goal — why the system is needed and how to measure success.
- Users and roles — who will work in it and what each may do.
- Processes — step by step, how the work is done (including exceptions).
- Features with priorities — must-have, nice-to-have, future.
- Data — what data is stored and where it comes from.
- Integrations — accounting, online store, bank, registers.
- Non-functional requirements — security, speed, languages, accessibility.
- Existing systems — what is being replaced and what has to be migrated.
User stories
A handy format: “As a warehouse worker I want to scan a product with my phone so that stocktaking is faster.” It helps the developer understand not only the “what” but also the “why”.
The most common mistakes
- Describing a solution rather than the problem.
- Treating all features as equally important.
- Not describing the exceptions.
Together with the developer
Requirements are often best refined together with the developer during the business process analysis — that’s the first stage of our work. The specification is also useful for a funding application — see how to prepare an IT project for funding.