Insights · 5 min read
Most requirements docs are 40 pages and still leave the hard questions unanswered. A shorter way to write one a developer can build from, and the parts buyers always forget.
By GGP Editorial
Most requirements documents are 40 pages and still leave the hard questions unanswered. A developer reads them, finds five ways to interpret the same sentence, and then builds the wrong thing politely. The problem is usually not too little detail. It is the wrong detail.
A useful spec is shorter than you think. It does not describe every screen and every button. It pins down the decisions that cost money to reverse, and leaves the rest to the people who build software for a living.
The fastest way to shrink a spec is to write the negative cases first. Users cannot place two orders for the same item. The admin cannot delete a paid invoice. The system must not lose an order when the network drops. These lines are short, and they do more work than three pages of feature description, because they tell the developer where the edges are.
Most buyers write down what they want and skip what they refuse to accept. The refusal list is the part that saves the project. It is also the part a cheap vendor will never ask you for, because it removes the ambiguity they were planning to bill later.
Write the negative cases in plain English, the way you would explain it to a new hire. If a rule takes two paragraphs to say, it is probably two rules, and one of them is hiding an assumption that will cause trouble later. A developer cannot code around an assumption you never wrote down.
A requirement that says the app should be fast, easy to use, and work offline is three requirements hiding in one. The developer cannot build it, and the tester cannot test it. Split it. Each requirement should be one thing, with one acceptance condition you can check: the order list loads within two seconds on a standard 4G connection.
If you cannot write the acceptance condition, you have not finished the requirement. That single rule filters out most of the vague documents I see, and it turns a spec into something a tester can actually verify against.
Then rank them. Mark each requirement as must, should, or could, and be ruthless about it. The must list is what version one actually is. The could list is what you drop the moment the budget tightens, and something always tightens the budget. Writing the ranking in the document means you decide what gets cut, instead of the vendor deciding for you at week six.
One more habit that helps: put one owner on the document. Requirements written by committee end up as a list of everyone's favorite feature and nobody's priorities. A single person who can say yes or no to a change keeps the spec from drifting, and gives the vendor someone to call when a question blocks the build.
| Section | Why it matters |
|---|---|
| Roles and permissions | Who can see and do what |
| Failure and edge cases | What happens when things break |
| Non-functional limits | Speed, volume, uptime, security |
| Integrations | Which systems it talks to |
| Out of scope | What you are deliberately not building |
Out of scope is the one everyone skips, and it is the cheapest way to avoid an argument later. Write down the features you are deliberately not building in version one. It stops scope creep before it starts, and it gives the vendor nowhere to hide when they try to bill for something you never asked for.
A good vendor reads your document and comes back with questions, not a price. The questions are the signal. If they quote a number without asking anything, they have not read it, or they plan to charge you for the ambiguity later.
Expect the first round to be uncomfortable. The vendor will point at lines you thought were clear and show you three readings of them. That is not the vendor being difficult. It is the document being tested before it becomes a budget, which is the cheapest time to find the holes.
Then the document becomes the contract. Every sentence you wrote is something they can be held to, and every sentence you left vague is something you will pay to clarify. So spend the time on the first draft, and hand it over in small chunks so you can watch how the vendor responds before you commit.
GlobeSoft reviews specs like this every week, for startups and for enterprises, across AI, IoT, fintech, payments, and mini-programs. We work in English and Portuguese and run overlap hours, so a client in Brazil or Singapore can walk the spec with the engineers who will actually build it, not a sales layer. The document gets shorter, the estimates get more honest, and the build starts on the same page instead of three interpretations apart.
Tell us what you are building and where you are today. We typically reply within 24 hours.
