A software project requirement document explains what a software system needs to accomplish, who it is for, how it should behave, and what conditions it must satisfy.

It is one of the most important documents created before software development begins because it converts a business idea into a set of requirements that a product team, designer, developer and tester can work from.

A requirement document should answer a simple question:

What exactly does the software need to do, and what should users and the business be able to expect from it?

That sounds straightforward.

In practice, poorly written requirements are one of the biggest causes of confusion in software projects.

Statements such as:

The application should be user-friendly.

The system should be fast.

Users should be able to manage their accounts.

The platform should be secure.

sound reasonable, but they are not sufficiently specific to guide implementation or testing.

A useful requirement needs enough detail to remove ambiguity without unnecessarily dictating how every line of code must be written.

This article explains what a professional software project requirement document should contain, how requirements should be written, which types of requirements need to be documented, what makes a requirement strong or weak, and how to determine whether a project is actually ready for development.

This is the fourth guide in our pre-development documentation series. It sits between the broader documentation checklist and the more technical software architecture document — the requirement document is where a product idea becomes something specific enough for technical documentation and architecture to be built on top of.

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Quick Answer: What Should a Software Requirement Document Contain?

A comprehensive software project requirement document should usually cover:

Requirement Area	What It Defines
Project Objective	Why the software is being built
Problem Statement	What problem the software is intended to solve
Target Users	Who will use the system
User Roles	Different types of users
Business Requirements	What the business needs to achieve
Functional Requirements	What the software must do
Non-Functional Requirements	How the software should perform
User Journeys	How users move through important workflows
User Stories	Specific user needs and expected outcomes
Business Rules	Rules that control system behaviour
Data Requirements	What information the system must store or process
Integration Requirements	Systems the software must communicate with
Authentication Requirements	How users establish identity
Authorization Requirements	What different users can access
UI/UX Requirements	Interface and interaction expectations
Error Handling	What happens when something goes wrong
Edge Cases	Unusual or exceptional scenarios
Security Requirements	Security expectations and restrictions
Performance Requirements	Response and processing expectations
Compatibility Requirements	Supported devices, browsers or platforms
Reporting Requirements	Information the system must produce
Notifications	Events that trigger alerts or messages
Acceptance Criteria	Conditions that determine whether a requirement is complete
Priorities	What must be built first
Dependencies	Requirements that depend on other systems or decisions
Assumptions	Conditions the requirements currently rely on
Constraints	Things the software must work within
Out-of-Scope Items	Things intentionally not included

A small project may combine several of these areas.

A complex platform may require separate documents for product requirements, functional specifications, technical requirements and acceptance criteria.

The important thing is that the required behaviour is documented clearly.

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What Is a Software Project Requirement Document?

A software requirement document is a structured description of what the software is expected to achieve and how it is expected to behave.

It sits between the business problem and the technical implementation.

For example:

Business statement

We want customers to be able to purchase products online.

Product requirement

Customers should be able to browse products, add products to a cart, enter delivery details, make a payment and view order status.

Detailed requirements

The application should:

1. Allow customers to add an available product to the cart.
2. Allow customers to modify product quantities.
3. Validate stock before checkout.
4. Calculate the order total.
5. Collect required delivery information.
6. Allow supported payment methods.
7. Create an order after successful payment.
8. Prevent duplicate order creation.
9. Display an appropriate message when payment fails.
10. Send the customer an order confirmation.

The first statement describes the goal.

The second describes the product capability.

The detailed requirements describe the expected behaviour.

That progression is what makes requirements useful to a development team.

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Why Requirement Documentation Matters

Software development becomes expensive when important decisions are made after implementation has already started.

A requirement document helps move those decisions earlier.

Good requirements provide a common reference point for:

• Business stakeholders
• Product managers
• Designers
• Architects
• Developers
• QA engineers
• Project managers
• Operations teams

Everyone should be working toward the same expected outcome.

Without that shared reference, the same feature can be interpreted differently by different people.

A client may think a feature is complete.

A developer may think additional work is required.

A tester may interpret the requirement differently.

A product manager may have assumed another behaviour.

The disagreement usually appears at the end of development, when changing the software is more expensive.

Clear requirements reduce that ambiguity.

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Business Requirements vs Product Requirements vs Technical Requirements

These terms are often mixed together.

They should not be.

Business requirements

Business requirements explain why the project exists and what the business needs to achieve.

Example:

The business needs to reduce manual order processing by allowing customers to place and track orders through an online platform.

Product requirements

Product requirements explain what the product needs to provide to achieve the business objective.

Example:

Customers should be able to create accounts, browse products, place orders and track delivery status.

Technical requirements

Technical requirements explain the technical conditions the system needs to satisfy.

Example:

The application must support authenticated API access, store transactional data reliably and integrate with the existing order management system.

All three are important.

A good project should connect them rather than treating them as unrelated documents.

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1. Project Objective

The requirement document should begin by explaining what the project is trying to accomplish.

The objective should be specific enough to establish direction.

Instead of:

Build a modern application.

A stronger objective would be:

Build a web application that allows customers to purchase products online, track their orders and manage their account without requiring manual support.

The objective becomes the reference point for evaluating later requirements.

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2. Problem Statement

The requirement document should explain the problem being solved.

For example:

Customers currently place orders through phone calls and email. The process requires manual entry by staff, creates delays and provides limited visibility into order status.

This context matters because the development team should understand the problem, not just a list of features.

Knowing the problem also helps when someone proposes a feature that does not actually contribute to the desired outcome.

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3. Target Users

The document should identify who will use the software.

Possible users include:

• Customers
• Employees
• Managers
• Administrators
• Partners
• Vendors
• Support staff
• External systems

For each important user type, the document should explain what they need from the system.

A customer and an administrator may use the same application but have completely different requirements.

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4. User Roles and Permissions

User roles should be documented early.

For example:

Customer

Can:

• View products
• Place orders
• View personal orders
• Update profile

Manager

Can:

• View orders
• Update order status
• Manage assigned staff

Administrator

Can:

• Manage users
• Manage products
• Configure system settings
• View reports

The role definition should go beyond naming roles.

The document should define what each role can and cannot do.

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5. Business Requirements

Business requirements describe what the organization needs the system to accomplish.

Examples include:

• Reduce manual work
• Improve customer visibility
• Automate approvals
• Centralize data
• Reduce processing time
• Increase transaction capacity
• Provide real-time reporting

Business requirements provide the reason behind the product features.

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6. Functional Requirements

Functional requirements describe what the software must do.

This is usually the largest part of a requirement document.

Functional requirements can cover:

• Registration
• Login
• Search
• Filtering
• Profiles
• Payments
• Orders
• Notifications
• File uploads
• Reports
• Administration
• Messaging
• Workflow approvals
• Data import
• Data export

The key is to describe expected behaviour rather than simply listing feature names.

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A Feature Name Is Not a Requirement

Consider this:

User management

That is a feature category, not a useful requirement.

A developer still does not know:

• Who can manage users?
• What information can be changed?
• Can users be deleted?
• Can accounts be suspended?
• Can roles be changed?
• Can passwords be reset?
• Can administrators view login activity?

A stronger specification would break the feature into actual behaviours.

For example:

Administrators can create a user account by entering the user's name, email address and assigned role.

Administrators can suspend an active account.

Suspended users cannot authenticate.

Administrators can reactivate suspended accounts.

Now the development and testing teams have something concrete to work from.

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How to Write a Good Functional Requirement

A strong functional requirement should make it reasonably clear:

Who performs the action?

What action occurs?

Under what condition?

What should the system do?

What should happen when the operation fails?

For example:

When an authenticated customer submits a valid order, the system should create an order record containing the selected products, quantities, delivery information and calculated total.

That is far more useful than:

The system should support orders.

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7. User Stories

User stories are another useful way of expressing requirements.

A basic structure is:

As a [type of user], I want to [perform an action], so that [desired outcome].

For example:

As a customer, I want to save delivery addresses so that I do not need to enter the same information for every order.

User stories are useful because they keep the user's goal visible.

However, a user story by itself is often insufficient for development.

It should generally be supported by acceptance criteria and additional business rules where necessary.

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8. User Journeys and Workflows

A requirement document should explain important end-to-end workflows.

For example, a registration flow might be:

User enters email

↓

System validates email

↓

Verification request is created

↓

User receives verification message

↓

User verifies email

↓

Account becomes active

↓

User is redirected to the application

This is much clearer than simply writing:

Users can register.

Workflows are particularly useful for complex processes involving multiple screens, systems or user roles.

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9. Business Rules

Business rules are conditions that the system must enforce.

Examples:

• A customer cannot place an order without a delivery address.
• A cancelled order cannot be shipped.
• Only administrators can modify system configuration.
• A discount cannot reduce the final price below the defined minimum.
• An employee cannot approve their own expense claim.

Business rules are critical because they represent actual organizational logic.

They should not be left entirely to developer interpretation.

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10. Data Requirements

The requirement document should identify the information the system needs to capture, process or display.

Examples include:

• Customer information
• Product information
• Orders
• Payments
• Documents
• Addresses
• Transactions
• Notifications
• Audit events

For important data, the requirement should establish:

• What information is required
• What is optional
• What format is expected
• Who can access it
• How it is used
• How long it should be retained
• Whether it can be deleted or modified

The detailed technical database design may live in a separate document.

The business need for the data belongs in the requirements.

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11. Input Requirements

Every important input should have clearly defined expectations.

For example, a phone number field may require:

• Mandatory or optional
• Accepted format
• Country code
• Maximum length
• Validation
• Error behaviour

Similarly, a document upload requirement should specify:

• Supported file types
• Maximum file size
• Number of files
• Naming rules
• Validation
• Failure handling

A field is not fully specified simply because it exists on a screen.

Its expected behaviour matters too.

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12. Output Requirements

The requirement document should also define what the system needs to produce.

Outputs can include:

• Screens
• Reports
• Emails
• Notifications
• PDFs
• Data exports
• API responses
• Dashboard metrics
• Status updates

For example:

After successful payment, the system should display an order confirmation containing the order number, items, total amount and delivery information.

This gives the development and QA teams a clear target.

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13. Search Requirements

Search often looks simple but requires precise requirements.

A search specification may need to define:

• Searchable fields
• Exact or partial matching
• Case sensitivity
• Ranking
• Filters
• Sorting
• Pagination
• Empty results
• Misspellings
• Search permissions

For example:

Users can search products by name and SKU and filter results by category and availability.

That is much more useful than:

Add product search.

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14. Notification Requirements

Notifications should be documented as specific events.

For example:

Event	Recipient	Notification
Account created	User	Email
Password reset requested	User	Email
Order placed	Customer	Email + in-app
Payment failed	Customer	Email + in-app
Order shipped	Customer	Email
Critical system event	Administrator	Alert

The requirement should also clarify whether notifications are mandatory, optional, immediate or asynchronous.

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15. Integration Requirements

If the software must interact with another system, that requirement should be documented early.

Examples include:

• Payment provider
• CRM
• ERP
• Accounting system
• Authentication provider
• Email platform
• SMS service
• Maps
• AI service
• Shipping platform

The requirement should explain:

• Why the integration exists
• What data needs to move
• When information is sent or retrieved
• What happens if the external system is unavailable
• What user-visible behaviour occurs when the integration fails

External systems often introduce constraints that can change the product experience.

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16. Authentication Requirements

Authentication requirements define how users prove their identity.

Possible requirements include:

• Email and password
• Mobile verification
• Social login
• Single sign-on
• Multi-factor authentication
• Password reset
• Account verification
• Session timeout

The requirement document should state which methods are needed rather than leaving the choice entirely open when it affects user workflows.

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17. Authorization Requirements

Authorization defines what different users are allowed to access.

For example:

Customers can only access their own orders.

Support staff can view customer records but cannot modify payment information.

Administrators can modify user roles.

These rules should be explicit.

A vague statement such as "role-based access will be supported" does not fully describe the requirement.

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18. Non-Functional Requirements

Functional requirements describe what the software does.

Non-functional requirements describe how the software should behave.

They can include:

• Performance
• Availability
• Reliability
• Security
• Scalability
• Usability
• Accessibility
• Maintainability
• Compatibility
• Recoverability

For example:

Functional requirement:

Users can search orders by order number.

Non-functional requirement:

Search results should be returned within the agreed performance threshold under expected production load.

Both matter.

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19. Performance Requirements

Avoid vague phrases such as:

The system should be fast.

Define performance in measurable terms wherever practical.

Performance requirements may address:

• Response time
• Concurrent users
• Processing time
• File upload duration
• Report generation
• API response
• Search response
• Page rendering

The exact targets should reflect actual business needs.

There is little value in defining an unnecessarily aggressive target that increases development cost without providing meaningful business benefit.

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20. Security Requirements

Security requirements should establish the security expectations of the application.

Depending on the project, these may include:

• Authentication
• Authorization
• Password handling
• Multi-factor authentication
• Encryption
• Session management
• API protection
• File upload restrictions
• Audit logging
• Administrative controls
• Data protection
• Secrets management

The requirements should focus on what the system must achieve.

The architecture and technical documents can later define how those requirements are implemented.

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21. Compatibility Requirements

The requirement document should state which platforms the system must support.

For example:

• Web
• iOS
• Android
• Desktop
• Specific browser categories
• Tablet
• Mobile

It may also define:

• Responsive requirements
• Screen sizes
• Supported operating systems
• Accessibility expectations

Without explicit compatibility requirements, different members of the team may test against different assumptions.

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22. Accessibility Requirements

Accessibility should be treated as a product requirement when it matters to the target users and business.

Requirements may include:

• Keyboard navigation
• Clear focus states
• Appropriate labels
• Sufficient text readability
• Screen reader support
• Alternative text
• Accessible forms
• Meaningful error messages

The exact requirements should be determined according to the product, target users and applicable obligations.

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23. Reporting Requirements

Reports should be documented separately from general dashboard requirements when they are important to business operations.

A report requirement should establish:

• Data included
• Filters
• Sorting
• Date ranges
• User permissions
• Export formats
• Refresh behaviour
• Calculations

For example:

Managers can generate a monthly sales report filtered by store and product category and export the results.

This is much clearer than:

Add sales reporting.

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24. Audit Requirements

Some systems need to record important actions.

Audit requirements may include events such as:

• User creation
• User deletion
• Permission changes
• Login attempts
• Payment changes
• Order modifications
• Administrative actions

The requirement should establish which events matter and who should be able to access those records.

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25. Error Handling Requirements

A good requirements document does not only describe successful behaviour.

It should also describe important failure states.

Consider a payment feature.

The requirement should address:

Payment succeeds

Create the order and display confirmation.

Payment fails

Do not mark the order as successfully paid and explain the failure to the user.

Payment times out

Define whether the transaction should be retried or placed into a pending state.

Payment succeeds but the response is delayed

Prevent duplicate orders and reconcile transaction status correctly.

Failure scenarios are part of requirements, not merely coding details.

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26. Edge Cases

An edge case is a situation that may not happen often but must still be handled correctly.

Examples include:

• User submits an expired form
• Product goes out of stock during checkout
• Duplicate payment request
• User loses network connectivity
• External API becomes unavailable
• User attempts to access deleted content
• Two administrators edit the same record
• Uploaded file exceeds limits
• Required information is missing

Important edge cases should be documented because they often expose the difference between a prototype and production-ready software.

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27. Acceptance Criteria

Acceptance criteria define what must be true for a requirement to be considered complete.

For example:

Requirement

Customers can reset their password.

Acceptance criteria

• User can request a password reset using a registered email address.
• The system should not expose whether an unrelated email address exists.
• The reset mechanism should expire according to the defined policy.
• User can create a new valid password.
• Previous authentication sessions are handled according to the security requirement.
• User receives an appropriate confirmation.

The acceptance criteria give developers a target and testers a validation method.

For the complete framework — including failure conditions, edge cases, permissions, and a reusable template — see our guide to what should be included in software project acceptance criteria.

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What Makes a Good Requirement?

A strong requirement should ideally be:

Clear

A reasonable reader should understand what is expected.

Specific

Important behaviour should not be hidden behind vague terminology.

Testable

Someone should be able to determine whether the requirement has been satisfied.

Consistent

The requirement should not contradict another requirement.

Feasible

The requirement should be technically and commercially realistic.

Necessary

There should be a reason for the requirement to exist.

Traceable

The requirement should connect back to a business or product objective.

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Examples of Weak and Strong Requirements

Example 1: Performance

Weak

The application should be fast.

Stronger

The application should return the authenticated dashboard data within the defined response threshold under the expected production workload.

The exact threshold should be agreed according to the project.

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Example 2: Login

Weak

Users should be able to log in.

Stronger

Registered users can authenticate using their approved credentials and are granted access according to their assigned permissions.

The supporting requirements should define invalid credentials, account status, password reset and session behaviour.

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Example 3: Search

Weak

Users can search products.

Stronger

Customers can search active products by name and SKU, view matching results and filter results by the supported product categories.

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Example 4: Security

Weak

The application must be secure.

Stronger

Administrative functionality must require authenticated access and only users with the required administrative permissions may perform administrative operations.

Specific security requirements should then cover authentication, authorization, data protection and monitoring.

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Example 5: File Upload

Weak

Users can upload documents.

Stronger

Authorized users can upload supported document formats up to the defined file-size limit. The system must validate uploaded files and display an appropriate error when an upload does not meet the requirements.

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Requirements Should Describe Outcomes, Not Just Implementation

A common mistake is writing requirements in a way that unnecessarily dictates the technical implementation.

For example:

Build this feature using a specific framework and library.

That may be appropriate when the technology is already a genuine project constraint.

However, in many cases the actual requirement is:

The system should validate uploaded documents before processing them.

The implementation may be handled in several technically valid ways.

Requirements should generally define what must be achieved.

Architecture and technical specifications should define how it should be achieved, where that decision needs to be established.

This separation gives the engineering team appropriate flexibility.

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Functional vs Non-Functional Requirements

This distinction deserves special attention.

Functional requirement

Describes a capability or behaviour.

Users can upload documents.

Non-functional requirement

Describes a characteristic or operational expectation.

Uploaded documents must be stored securely and remain accessible only to authorized users.

One describes what happens.

The other describes how the system must behave while doing it.

A complete requirements document needs both.

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How Requirements Should Be Prioritized

Not every requirement has the same importance.

A practical priority model can divide requirements into categories such as:

Critical

The product cannot operate without it.

High

Important for the primary user experience or business process.

Medium

Useful but does not prevent the primary workflow from working.

Low

Nice to have or suitable for a future release.

Another common approach is to separate:

Must have

Should have

Could have

Not planned for this release

The specific framework matters less than having a clear prioritization method.

Without prioritization, everything eventually becomes urgent.

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MVP Requirements

A minimum viable product should not mean a minimum amount of documentation.

It means the first release contains the minimum functionality required to test the intended product or business outcome.

The requirements document should therefore distinguish:

Core MVP requirements

from:

Post-MVP requirements

For example:

MVP

• Registration
• Login
• Product browsing
• Cart
• Checkout
• Payment
• Order tracking

Future

• Loyalty program
• Advanced recommendations
• Referral system
• Subscription plans

This prevents future ideas from quietly becoming current scope.

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Dependencies Between Requirements

Some requirements cannot be implemented independently.

For example:

Requirement A: Users can create accounts.

Requirement B: Users can save payment methods.

Requirement B depends on account identity and authentication.

Similarly:

Requirement A: Product inventory is maintained.

Requirement B: Checkout validates current inventory.

The requirement document should identify important dependencies.

This helps the team plan implementation order and identify blockers early.

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Assumptions in Requirements

Requirements are often based on assumptions.

For example:

• The client will provide product data.
• An external service will expose the required API.
• Existing user records can be migrated.
• A particular workflow will remain unchanged during the first release.

These assumptions should be documented.

If an assumption changes, the associated requirements may need to change too.

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Constraints

Requirements should also document important constraints.

Examples include:

• Existing technology
• Legacy integrations
• Budget
• Delivery deadline
• Existing infrastructure
• Required platforms
• Data restrictions
• Security requirements
• Business processes

A requirement is only useful if it can actually be delivered within the known constraints.

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Out-of-Scope Requirements

One of the most useful parts of a requirement document is often what it does not include.

Examples:

• Native mobile application
• Offline mode
• Advanced analytics
• Multi-language support
• International payments
• Complex reporting

These items may become future requirements.

Explicitly identifying them prevents people from assuming they are included in the current release.

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Requirement Traceability

For larger projects, important requirements should be traceable from business objective through to implementation and testing.

A simple chain can look like:

Business Objective

↓

Product Requirement

↓

Functional Requirement

↓

Technical Requirement

↓

Implementation

↓

Test Case

↓

Acceptance

For example:

Business Objective: Reduce manual order processing.

↓

Product Requirement: Customers can place orders online.

↓

Functional Requirement: Authenticated customers can create an order after completing checkout.

↓

Technical Requirement: Order creation must be processed through the approved backend service.

↓

Test: Verify that a valid checkout creates exactly one order.

↓

Acceptance: Order is created correctly and customer receives confirmation.

This makes the project easier to manage and audit.

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How Requirements Should Be Reviewed

Requirements should be reviewed before development begins.

A practical review can involve:

Business review

Does the requirement solve the intended business problem?

Product review

Does it represent the intended user experience?

Technical review

Can it be implemented within the known architecture and constraints?

QA review

Can the requirement be tested objectively?

Security review

Does it create security or access implications?

Not every project needs a large review committee.

The review should match the project's complexity and risk.

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What Should Be Finalized Before Development?

Not every requirement needs to be permanently frozen.

However, the following should generally be sufficiently clear before development begins:

• Core user journeys
• Major features
• User roles
• Important business rules
• Core integrations
• Critical data requirements
• Major security requirements
• Platform requirements
• MVP scope
• Acceptance expectations

Low-priority enhancements can often be refined later.

The goal is not to eliminate change.

The goal is to prevent avoidable uncertainty from entering development.

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What Can Change During Development?

Requirements will sometimes change.

A new business insight may appear.

A customer may behave differently than expected.

A technical constraint may be discovered.

A regulatory condition may change.

A third-party service may introduce a limitation.

The right approach is not to pretend requirements can never change.

The right approach is to control changes.

A meaningful change should be evaluated for:

• Product impact
• Technical impact
• Design impact
• Testing impact
• Schedule impact
• Cost impact
• Security impact

Then the relevant documentation should be updated.

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Requirement Change Management

A simple requirement change process can be:

1. Change proposed
2. Requirement reviewed
3. Impact assessed
4. Priority determined
5. Cost and timeline assessed
6. Change approved or rejected
7. Requirement updated
8. Related design and technical documentation updated
9. Development proceeds

This protects both the client and the development team.

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Who Should Own the Requirement Document?

Requirement ownership depends on the organization and project.

It may involve:

• Product owner
• Business stakeholder
• Product manager
• Project manager
• Business analyst
• Technical lead
• Client representative

The important thing is that someone is responsible for maintaining requirement accuracy.

A document that nobody owns will eventually become outdated.

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The Ortem Requirements Quality Test

At Ortem Technologies, a simple way to test the quality of a requirement is to ask five questions:

1. Can a developer understand it?

If not, it needs clarification.

2. Can a tester verify it?

If not, it may not be specific enough.

3. Can the business explain why it exists?

If not, its value should be questioned.

4. Can we identify what happens when it fails?

If not, the requirement may be incomplete.

5. Can we tell when it is finished?

If not, acceptance criteria are missing.

If a requirement passes all five questions, it has a much stronger chance of being useful in development.

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Complete Software Requirement Document Structure

A practical requirement document can use the following structure.

1. Document Information

• Project name
• Version
• Date
• Owner
• Review status

2. Project Overview

• Business problem
• Objective
• Expected outcome

3. Users and Roles

• User types
• Roles
• Permissions

4. Business Requirements

• Business goals
• Processes
• Rules

5. Product Requirements

• Features
• User journeys
• Workflows

6. Functional Requirements

• Detailed system behaviour

7. Non-Functional Requirements

• Performance
• Security
• Availability
• Scalability
• Compatibility

8. Data Requirements

• Data collected
• Data processed
• Data displayed

9. Integration Requirements

• External systems
• APIs
• Data exchange

10. UI/UX Requirements

• Screens
• Workflows
• Interaction requirements

11. Error and Edge Cases

• Failure scenarios
• Exceptional behaviour

12. Acceptance Criteria

• Conditions of completion

13. Priorities

• MVP
• High
• Medium
• Future

14. Dependencies

• Technical dependencies
• Business dependencies

15. Assumptions

• Known assumptions

16. Constraints

• Business and technical restrictions

17. Out-of-Scope Items

• Explicit exclusions

18. Open Questions

• Decisions still awaiting confirmation

This structure can be simplified for small projects or expanded for complex systems.

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Requirement Document Example

Imagine a platform that allows customers to book appointments.

A weak requirement might say:

Customers should be able to book appointments.

A better requirement would look like:

Requirement

Authenticated customers can book an available appointment slot with an eligible service provider.

Preconditions

• Customer must have an active account.
• Service provider must have available slots.
• Customer must provide the required booking information.

Behaviour

1. Customer selects a service.
2. System displays available providers.
3. Customer selects a provider.
4. System displays available appointment times.
5. Customer selects a valid time.
6. System verifies that the slot remains available.
7. Booking is created.
8. Confirmation is displayed.
9. Confirmation notification is sent.

Failure scenarios

• Selected slot becomes unavailable.
• Required information is missing.
• Booking service becomes unavailable.
• Customer is not authorized.

Acceptance criteria

• Only available slots can be booked.
• Two customers cannot successfully reserve the same slot.
• A confirmed booking receives a unique identifier.
• Customer receives confirmation after successful booking.

Now the requirement is something that development and QA teams can actually work with.

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Requirements for AI Software Projects

AI applications introduce additional requirements that traditional software projects may not have.

An AI requirement document may need to define:

• AI use case
• Expected model behaviour
• Input types
• Expected outputs
• Knowledge sources
• Retrieval requirements
• Prompt requirements
• Tool access
• Agent behaviour
• Human approval
• Evaluation criteria
• Confidence or uncertainty handling
• Hallucination mitigation
• Data privacy
• AI-specific security
• Monitoring
• Cost constraints

For example:

The AI assistant should answer questions about the company's internal documentation.

This is not enough.

The requirement should also address:

• Which documentation can it access?
• How is information retrieved?
• What happens when no relevant information exists?
• Should the assistant refuse unsupported questions?
• Should answers contain references to internal documents?
• What information must never be disclosed?
• How should responses be evaluated?
• Who can access the assistant?

AI requirements need to describe both desired capability and acceptable behaviour.

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Common Software Requirement Mistakes

Writing requirements as vague goals

"Make the application easy to use" does not define an implementation or acceptance condition.

Listing features without behaviour

"Reporting" does not explain what reports are required.

Ignoring failure states

Successful workflows are only part of the system.

Mixing requirements with implementation

Not every requirement needs to dictate a specific technology.

Making everything a priority

If everything is critical, nothing is prioritized.

Forgetting exclusions

Unwritten exclusions often become assumed scope.

Ignoring dependencies

External systems and client inputs can affect delivery.

Failing to update requirements

An outdated requirement document can become more dangerous than no document because people assume it is accurate.

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Final Software Requirement Checklist

Before development starts, the requirement document should allow the team to answer:

Business

• What problem are we solving?
• Why does the project exist?
• What outcome is expected?

Users

• Who will use the system?
• What roles exist?
• What can each role do?

Product

• What are the major workflows?
• What features are required?
• What is part of the MVP?

Functional

• What should each feature do?
• What inputs are required?
• What outputs are expected?

Business Rules

• What conditions must the system enforce?

Data

• What information must be captured?
• Who can access it?
• What happens to it?

Integrations

• Which external systems are involved?
• What happens when an integration fails?

Security

• How should identity and access work?
• What information requires protection?

Non-Functional

• What performance, availability and scalability expectations exist?

Errors

• What happens when something goes wrong?

Edge Cases

• What unusual situations must the system handle?

Acceptance

• How will we determine that each requirement is complete?

Scope

• What is included?
• What is explicitly excluded?

Dependencies

• What must happen before this requirement can be implemented?

Change

• How will future requirement changes be handled?

If the team cannot answer these questions, the requirements are probably not yet mature enough for development.

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Final Takeaway

A software requirement document should not be a collection of vague feature descriptions.

It should provide a clear, structured explanation of what the software is expected to accomplish and how it should behave.

A strong requirement document connects:

Business objectives

to

User needs

to

Product functionality

to

System behaviour

to

Technical expectations

to

Acceptance criteria

The document should establish enough clarity for developers to build, testers to validate, designers to understand workflows and business stakeholders to know what they are actually approving.

It should also make uncertainty visible.

Open questions should be recorded.

Assumptions should be identified.

Dependencies should be documented.

Important exclusions should be written down.

Requirements should be prioritized.

And when requirements change, the impact should be assessed rather than allowing scope to expand silently.

The goal is not to freeze software development before it begins.

The goal is to make the starting point clear enough that the development team is not forced to guess.

At Ortem Technologies, we believe a good requirement should pass one simple test:

Can the team understand what needs to be built, why it needs to be built, and how everyone will know when it is actually done?

If the answer is yes, the requirement is doing its job.

If the answer is no, writing more code is not the solution.

The requirement needs more clarity first.

"Requirement" is also one of the most conflated terms in software projects — mixed up with scope, specifications, and the Statement of Work more often than any of the others. See what actually separates the four.

Want your requirements pressure-tested before they reach a development team? That review is built into every custom software development engagement we run.

Get your requirements reviewed →