Technical Specification for Software: How to Write One

Every developer will understand the phrase "we need a convenient program for the store" in their own way: estimates will differ many times over, and the finished product will not be what you imagined. A technical specification (TS) exists precisely so that the client and the contractor understand the result in the same way. We look at why you need a TS for development, who writes it, what sections it consists of and which mistakes to avoid, with examples of wording.

What a technical specification is and why you need it

A TS is a document that describes what the future system must do, who will use it and under what conditions the work is considered complete. It has three functions:

• Shared understanding. The client, manager, designer and programmers see the same result.
• Basis for estimation. Without a clear list, it is impossible to calculate cost and timeline in a well-founded way.
• Acceptance criteria. It is clear in advance what to check at delivery, which means fewer disputes.

Who writes the TS

There are three ways:

1. The client writes it. They know the business from the inside but may miss technical details.
2. The contractor writes it. The document is complete from the technical side, but business nuances may be lost.
3. Together, at the analysis stage. The client talks about processes and goals, an analyst or project manager asks questions and drafts the document, and the client approves it. In practice this is the most effective option.

Even if you write it yourself, you do not need a perfect document. A clear draft written from the business point of view already helps the contractor a lot.

TS structure: main sections

Project goal and the problem being solved

Briefly: how you work now, what gets in the way, what should change after launch. For example: "Wholesale orders are taken in Telegram and by phone, debts are kept in Excel; the goal is to see all orders and payments in one system."

Users and roles

Who works in the system and what each person sees: owner, manager, storekeeper, cashier, customer. If you define access rights in advance, many security questions resolve themselves.

Key processes and scenarios

Describe important processes step by step: "The manager creates an order → selects the customer → adds goods and quantities → the system checks stock → the order goes to the warehouse → the storekeeper picks it and changes the status." Such scenarios are more useful than a dry list of functions.

List of functions with priorities

Mark each function as mandatory (launch is impossible without it), important (needed in the first version) or for later. This helps split the project into stages and manage the budget.

Screens and prototype

A list of the main pages or screens, hand-drawn sketches, screenshots of similar programs. A picture is clearer than any words.

Data

What is stored in the system: a customer (name, phone, address, price category), a product (name, article number, unit of measure, prices), an order and so on. State separately whether data needs to be moved from Excel or an old program.

Integrations

What the system must work with: payment services, accounting software, a Telegram bot, SMS, a website. For each integration, say what data is passed and in which direction.

Technical and non-functional requirements

• Platforms: web, Android, iOS, Windows.
• Interface languages: Russian, Uzbek (Latin, Cyrillic).
• Approximate number of users and branches.
• Work on a weak internet connection, whether an offline mode is needed.
• Backups, access rights, an action log.

Acceptance criteria

For each key function, describe what "works" means. For example: "When an order is confirmed, stock in the warehouse decreases automatically; if there is not enough goods, the system warns the user."

What is not part of the project

List what will not be included too: for example, the first version has no mobile app and no accounting reports. This removes misunderstandings later.

Vague and precise requirements: examples

Vague	Precise
The system must be convenient	The manager creates an order on one page, choosing the customer and goods via search
We need reports	The owner sees a sales report filtered by date, manager and branch and exports it to Excel
It must work fast	The order list opens without a long wait even over mobile internet
Connection with Telegram	When there is a new order, the responsible manager gets a notification in Telegram
It must be secure	The cashier sees sales only for their own branch and cannot change prices

The rule is simple: anyone who reads a requirement should understand it the same way and be able to check it.

Common mistakes

• Describing a solution instead of a problem. Instead of "make it like such-and-such program", write what task needs to be solved.
• A long list without priorities. If everything is important, nothing is.
• Not asking the users. The real work of a cashier and storekeeper differs from the picture in the office.
• Contradictions. Give the document to an outsider to read.
• "Freezing" the TS forever. Requirements change and that is normal; the main thing is to agree changes in writing and assess their effect on timeline and budget.

A simple TS template

1. Company and project goal.
2. Current process and problems.
3. Users and roles.
4. Key scenarios.
5. List of functions with priorities.
6. Data and its migration.
7. Integrations.
8. Technical requirements.
9. Acceptance criteria.
10. What is not part of the project.

In a TS for a website, the page structure, design and search optimization requirements come to the fore; when building websites we clarify these sections first. In a TS for a CRM or ERP, processes, roles and reports are at the center.

Frequently asked questions

Can development start without a technical specification?

For a small task a short written agreement is enough. But for a CRM, an app or a complex website, starting without a TS sharply raises the risk of disagreements about price, timeline and result.

How detailed should the TS be?

Detailed enough that the developer can estimate the work without further questions, and you can check the result. Small details can be clarified during the prototype and development stage.

Do you help prepare a technical specification?

Yes, many projects start with an analysis stage: we ask questions, study your processes, prepare the TS and agree it with you.

UFLEX is an IT team from Namangan. We build websites, mobile apps, Telegram bots, CRM/ERP, and inventory and POS systems, and support the project from requirements gathering and the TS through to hosting on a server and support. We work remotely with clients from Tashkent and other cities. To turn your idea into a clear technical specification, leave a request or message us on Telegram.