AUG.30.2022

FUNCTIONAL REQUIREMENTS VS NON-FUNCTIONAL REQUIREMENTS:
DIFFERENCES
& EXAMPLES

FUNCTIONAL REQUIREMENTS VS NON-FUNCTIONAL REQUIREMENTS:
DIFFERENCES & EXAMPLES

Semyon Scherbak
Business Analyst at Freshcode
Imagine you are preparing a holiday feast. Whatever the occasion, cooking gourmet meals, crafting cozy decor, and preparing garden zones are pretty challenging tasks. What's the menu? How many guests? Photographer?

It's the same story with building apps. Crafting intuitive UI, creating the most elegant business architecture, and providing systems with top-notch functionality is a kind of software development fine art.

Here's where requirements matter. Functional and non-functional, they play a vital role in the development process. Let's explore the reasons why.

1. WHAT ARE FUNCTIONAL REQUIREMENTS?

According to Statista, the main reasons why startups did not work out in 2022 were running of funds (38 %), and no market need (35%). Flawed business models, cost issues, and mismatching team skills were named among other pitfalls ⛔️

Most of these issues can be caused by one seemingly indirect thing — poorly written product requirements. Well-thought and documented, they are essential to any project.

In the tech world, requirements are generally split into two types: functional and non-functional. Both of them define desired system behavior, but the different sides of the last.

Functional and non-functional requirements form a clear vision of the future product and serve as a roadmap for the development team.

Let's break down these two.

Functional requirements define actions the product must provide in order to benefit users. Simply put, they describe:
what precisely your product must do — its functions and features
business logic required to meet user needs and perform actions correctly
way the product will fulfill regulatory and compliance needs
These requirements are determined by the business needs and task analysis. They can be documented and described through the use cases.

To start with simple functional requirements examples, let's look at the... coffee cup.
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Software requirements (both functional and non-functional) are crafted by business analysts, in consultation with the development team, including software engineers, solution architects, and other IT gurus.

2. WHAT IS A NON-FUNCTIONAL REQUIREMENT?

While functional requirements set is a kind of guide to the product's underhood and its core features, non-functional requirements specify quality attributes designed to improve the product's functionality and user experience.
examples of non functions><meta itemprop=
They are various "itys", serving as pillars for the strong vault of great user experience:
Usability
Capacity, Performance, and Scalability
Data Integrity and Interoperability
Security
Reliability, Maintainability and Recoverability
Defining these NFR types upfront provides a handy checklist to make sure you're not missing critical requirements for the future product.

If you want to expand your software product along with your business, saying "product must be scalable" is not enough.

You need to be specific, so you might define this point as "develop a system that can manage at least 100,000 users over the next 24 months, so customers don't experience app crashes and errors".

Lack of non-function requirements can result in vague project scope and a disconnect between the software development plan and the client's expectations.

Freshcode Tip
Remember that realizing 100% of each non-functional requirement's potential isn't possible; for instance, the security requirement can conflict with usability or availability. This is why it's so important to prioritize each requirement and identify the most crucial of them.

3. DIFFERENCE BETWEEN FUNCTIONAL AND NON FUNCTIONAL REQUIREMENTS

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If functional requirements define the product's key features (what does it have to do), non-functional requirements determine the way it should be done (how does it have to do it). Their key difference is that the first ones are vital for the system; without meeting these, your product simply won't work.

Non-functions, in turn, focus on a user experience; the system will work without them. The other thing is that it will lose its meaning — who'll buy a guitar with a bad finish, strings that break too quickly, and no strap button? You can play such an instrument, but will you enjoy it as Slash enjoys his Gibson Les Paul on the stage? The answer is obvious: no.

So, don't take this in a way that working on non-functional requirements is less significant. Remember that user-centered design rocks: unless the app is user-friendly, your project will not succeed just as well.

Therefore, only the yin-yang combination of functional vs non-functional requirements matters — one cannot exist without the other ☯️

4. HOW TO WRITE FUNCTIONAL VS NONFUNCTIONAL REQUIREMENTS?

Here we want to guide you through the key points on the BA's map and show why all of them are non-skippable stages of app development.

Business analysts are responsible for creating requirements, both functional and non-functional. This process includes different stages, from calls and discussions with stakeholders, discovering their pain points, needs, and expectations, to designing all the data into structured requirements documentation.

This documentation supports the decision-making process, builds a strong background for further product development, and speeds up time-to-market.
Project Vision Document (PVD)
Project Vision Document describes a compelling idea of the software development project. It defines the product or service to be developed specified in terms of the stakeholder's key business needs, product mission, and desired functionality.
Requirement Management Plan (RMP)
Requirements Management Plan is typically created as a piece of the scope management process. It's intended to set forth the plans and procedures for gathering documentation and managing the project requirements.

The primary purpose is to ensure that all stakeholder and business requirements are captured, analyzed, managed, and addressed properly.
Software Requirements Specification (SRS, SRD)
Software Requirements Specification is a document outlining the feature set and performance standards for the future product. It describes the functionality the product must have in order to meet clients' demands.
Freshcode Tip
You can find detailed info on how to create a perfect SRS and write use cases in our article: Software Requirements Document: How To Create| Tips From Developers
    function and non function requirements artifacts ><meta itemprop=
    Delve into the business context

    ✔️ Project Background

    ✔️ Project Vision

    ✔️ Business Requirements

    Investigate end-users needs

    ✔️ User Roles

    ✔️ User Requirements

    Design UX system according to user requirements

    ✔️ Wireframes
    Prepare operational documentation

    ✔️ Functional and Non-Functional Requirements
    Сhoose the right architecture for the software

    ✔️ Architecture Diagram
    Estimate resource costs for the project ↓

    ✔️ Work Breakdown Structure
    Prioritize product features

    ✔️ Software Development Plan

    ✔️ Development Time Frame

    Want to know more about key business analysis documentation to start your project?

    5. HOW DO WE WORK WITH REQUIREMENTS AT FRESHCODE?

    After years of analyzing and implementing various techniques and approaches, we maximally simplified our requirement engineering process without loss of quality.

    By puzzling clients' and users' needs and creating a clear picture of the future software product, we
    find the strengths and weaknesses of each solution. Agreed with the client, the best possible is chosen. Thus, both sides save time and costs, preventing cases when hard work is going down the drain.

    Here is a brief step-by-step guide on how we process product requirements, from the initial discussion to the final documentation:
    functional vs non functional requirements ><meta itemprop=

    A good business idea is a great start. We just assist you to strengthen it with the best business analytics approaches, including software requirements engineering.

    We are always ready to have a talk about tech-savvy business strategies through the prism of software development. If you want to know more about our expertise, product delivery process, or get Freshcode estimation of resource costs for your project - we offer you a free consultation (and warm welcoming) ❤️

    Or just contact our COO on Linkedin to get info about Freshcode solutions.

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