Functional requirements in an SRS document (software requirements specification) indicate what a software system must do and how it must function; they are product features that focus on user needs.
As an SRS document contains a detailed description of software requirements and lays the groundwork for technical teams, investors, managers, and developers, delineating functional requirements is a big part of writing it.
There are several methods to write functional requirements, but the most common method is by constructing user stories and using user story formats: as a ___, I want to be able to ___ so that ___.
For example: as a customer, I want to be able to view all the top products so that I can choose the best one that suits me.
The above example’s technical function is a feature that enables customers to view the top products.
As you see, user stories put the actual end-users first by considering their needs and acting as their counterpart, and this effectively specifies a software product’s necessary functional requirements since they focus on user needs.
Read what user stories and epics are in detail in another blog post.
Different types of functional requirements in an SRS document are:
- Business rules
What do you want your system to do? What are the features you need so you can achieve your goals?
You need to define every system activity for each function within the system and address all functional requirement types. That’s why this section will probably be the longest amongst the others as many requirements may fall under this categorization.
- Transaction corrections, adjustments, and cancellations
These requirements examine every transaction’s entry, changing, deleting, canceling, and error checking.
- Authentication functions
They concern the information users share with the system and their authentication level.
- Authorization levels
These functions determine various system access levels and decide who can CRUD (change, read, update, or delete) information.
- Audit tracking
Audit tracking is the process of tracking critical data.
- External interfaces
These functions concern the external interface of systems other than the main system.
- Certification requirements
Your organization might require certifications to work on the system, such as security certifications.
- Searching/reporting requirements
This section of requirements will tell you how users can search and retrieve data.
- Historical data
You will have a growth of data if your database is dynamic, so you need to define storage requirements to accommodate these data.
- Archiving
Your system’s data may grow beyond your storage capacity, so the projects must have the capability to archive the data for long-term storage.
- Compliance, legal, or regulatory requirements
These are laws, regulations from the government, and even internal policies that the organizations and their systems must follow.
- Algorithms
Algorithms capture any formulas or manipulations of data elements that need to occur.
- Database
The elements and formats you should use when defining what data needs storing in a system.
- Backup and recovery
You will need this function in case your system crashes and wipes out all your data.
If you want to learn more about functional requirements, you can check out Requirements Writing for System Engineering by George Koelsch on Google Books.
But how to write specifications when you know all the necessary software requirements?
Functional requirements examples
The following functional requirements examples are taken from our estimation document sample. You can download the full PDF for free on WINaTALENT’s website.
The project is a local job-finding website where applicants create a profile, upload their resume, view available job opportunities, and apply for them.
The other party is the employers that purchase accounts to post new jobs and receive requests and resumes.
- User story 1: as an applicant, I must be able to register and enter the website
Functional requirements:
- Sign-up and register page
- Logging in with Google and its verification
- Phone number verification
- An “I forgot my password” section that sends a link to the verified email
- User story 2: as an applicant, I must be able to conduct a resume on the website and edit and print it
Functional requirements:
- Completing, editing, adding, and deleting different fields in the resume
- Downloading and printing the resume
- Displaying the resume’s completion progress
User story 3: as an applicant, I must be able to view job opportunities and explore them by using different filters.
Functional requirements:
- Applicant’s dashboard page
- A page with a list of the posted jobs
- A feature to filter and organize the posted jobs based on skill, date, and other descriptions
- A feature that enables applicants to explore different jobs and organize them based on company, scale, pay rate, or other descriptions
Since a lack of proper requirements specification causes 68% of IT projects’ failure, we at WINaTALENT pay extra attention to this step of our SRS and estimation document writing.
So, lean on us to manage your project and find the perfect talent and specialist on our platform.
This was a great explanation for me as a junior software engineer, thanks.
Very informative, thanks.
Thanks a lot. It helped.
It is clear explainations. thank you.
Very good explanation ,clear and easy to understand.
Excellent explantation .thanks