Understanding Software Architecture: The Dance of Functional Requirements and Quality Attributes
Tags: architecture, codenewbie, learning
Published: 2023-07-27 15:30:00

Hey there, future software architect! You're on a journey to understand and master the intricacies of software architecture, and I'm here to help you navigate. By the end of this piece, you'll have a deep understanding of the two main categories of requirements that guide your software's architecture: functional requirements and quality attributes.

## What's In a Requirement?

Software architecture is a lot like a well-rehearsed dance. There's rhythm, flow, and each step has a purpose. In our dance, the steps are defined by two types of requirements: functional requirements and quality attributes. These are the driving forces behind every decision you'll make in crafting your software's architecture.

![Basic Waltz](https://media4.giphy.com/media/v1.Y2lkPTc5MGI3NjExcGx3eDhxOXNsZ2FsY2V3MXljdnE5ODVjbHU0bWU1cTh3Z3VzdGFzcSZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/4Zf5tmTRmR7kL3tCsU/giphy.gif)
<figcaption><a href="https://giphy.com/gifs/evite-dance-moves-ballroom-4Zf5tmTRmR7kL3tCsU">via GIPHY</a></figcaption>

## The Functionality Waltz: Understanding Functional Requirements

Let's first waltz through functional requirements. These are your software's core behaviors. They’re what your software needs to do to serve its purpose and provide value to the user. A functional requirement for an email service, for example, would be "the ability to send and receive emails."

Think of functional requirements as the necessary moves in our dance. Without them, we don't have a performance. They’re the foundation upon which your software stands, the bricks and mortar of your digital construction.

## Functional Requirements: Non-Negotiable and Essential

Here's the deal with functional requirements: they're non-negotiable. They're essential capabilities your software must have. Imagine a car without an engine or wheels. It's not really a car, is it? Same goes for your software.

While functional requirements are critical, there's a flip side: these aren't all that distinguish your software from others. After all, many apps allow you to send and receive emails. What makes your software unique? That's where quality attributes come in.

![Beautiful Tango](https://media3.giphy.com/media/v1.Y2lkPTc5MGI3NjExemFrejJpYW9ldG9qcWFsOGMwM3VlOXcwcnBzbzk1ajNxdGF2N2NveSZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/jtRVA6tniiHFowozBf/giphy.gif)
<figcaption><a href="https://giphy.com/gifs/CBSAllAccess-tango-why-women-kill-wwk103-jtRVA6tniiHFowozBf">via GIPHY</a></figcaption>

## Tango with Quality Attributes: Understanding Non-Functional Requirements

Quality attributes, also known as non-functional requirements, determine the characteristics your software should have. They dictate how well your software performs its functions and integrates into the user’s world.

It’s about the degree to which your software delivers its functions: How fast is it? How easy is it to use? How secure is it? Can it be easily updated and maintained? All these answers are defined by quality attributes.

Picture this: You've been asked to build a bridge. Your functional requirement is simple – the bridge must allow cars to cross a river. But imagine if that was your only consideration. A wooden plank might suffice, right? But now, add in quality attributes. The bridge must support heavy vehicles, withstand strong winds, and last for decades with minimal maintenance. Suddenly, your simple wooden plank won't cut it anymore.

That's exactly how quality attributes work in software architecture. They raise the bar, ensuring your software is not just functional, but exceptional.

## Quality Attributes: The Lifeblood of Your Architecture

Why care so much about quality attributes? Because they shape the user experience and the longevity of your software. Ignoring quality attributes can lead to software that works, but not very well or for very long. It's like building a beautiful mansion on a weak foundation. It might look good for a while, but eventually, it'll crumble.

Take, for example, a mobile banking app. It's not enough for it to allow transactions (functional requirement). It needs to be secure, reliable, and user-friendly (quality attributes). Without these, no matter how well it performs its basic function, it will not be adopted by users.

## The Balancing Act: Harmonizing Functional Requirements and Quality Attributes

In our dance of software architecture, functional requirements and quality attributes must move in harmony. One without the other creates a disjointed performance. Too much emphasis on function, and you risk a clunky, inefficient product. Too much focus on quality attributes, and you might create a sleek masterpiece that does... well, nothing much.

Striking the right balance isn't always easy, but it's necessary. Here's how you can do it:

1. **Start with a clear understanding of your users’ needs**. This includes both what they need the software to do (functional requirements) and how they need it to perform (quality attributes).
2. **Prioritize requirements**. Not all requirements are created equal. Some are essential, others are nice-to-have. Knowing where each requirement stands helps balance your focus.
3. **Iterate and refine**. As you develop your software, continually revisit your requirements. Refine them based on user feedback, emerging technology trends, and your evolving understanding of the project.
4. **Communicate effectively**. Ensure everyone involved in the project understands the requirements and their priority. This common understanding is crucial for making informed decisions.

## Your Next Steps: Be the Choreographer

You've learned the steps, now it's time to choreograph your dance. Remember, great software is not just about what it does, but also how well it does it. As you dive into your next software project, remember to consider both your functional requirements and your quality attributes. Use them to guide your decisions and to create software that truly meets your users' needs.

Now, step onto the dance floor. Your users await your performance.