What’s the difference between software architecture and design?

Building software is a complicated process made up of many different parts. Among them are developing software architecture and design. For some reason, these two critical stages of software development are often confused with one another. This confusion can lead to misunderstandings that may put the entire development process at risk.

Read this article to find out what software architecture and software design are and how they differ from one another.

Defining software architecture and software design

Software architecture refers to the process of translating software characteristics into a structured solution that matches business and technical requirements. What are the software characteristics? They’re traits such as security, flexibility, scalability, or reusability. 

Software architecture focuses on developing the skeleton and high-level infrastructure of software. Software design, on the other hand, concentrates on the code level design. It addresses problems like the functions of individual modules, the scope of classes, the purposes of different functions, and the like. 

What is software design?

Software design is all about building a design plan that delves into the different elements that make up a system. It shows how they work together to fulfill the system requirements.

Why do development teams carry out software design? Developing a design plan allows negotiating system requirements, as well as setting expectations with customers and stakeholders (for example, the direct management or the marketing department). A design plan serves as a valuable point of reference throughout the development process. It works like a blueprint that guides teams in the implementation of tasks such as coding, design, integration, and testing.

Note that a design plan always comes after:

• requirements analysis,
• risk analysis,
• and domain analysis.

Software design aims to help developers transform requirements into implementation. That’s why you should expect the software design process to produce these artifacts:

• Software requirements specification – a document that describes the expected behavior of the system during interactions with users, hardware, and other systems, in the shape of functional and nonfunctional requirements. The requirements should be actionable and measurable. They also need to be traceable to business requirements.
• High-level design – this type of design fragments the system design into a more specific view of subsystems and modules. Most importantly, it focuses on how the system implements with modules and how these modules interact with one another.
• Detailed design – software design also generates a detailed system design that delves into the problem of implementing modules. It comes in handy to development teams because it defines the logical structure of every module and its interface for communicating with other modules.

Example: SOLID

To help you understand the role software design plays in the process of building software, let’s take a closer look at one of its key components: the SOLID principle.

SOLID refers to the following principles: Single Responsibility, Open Closed, Liskov substitution, Interface Segregation, and Dependency Inversion.

Each of these principles derives from battle-tested ways of developing software. For example, the Single Responsibility Principle states that each class should have only one responsibility. The Interface Segregation Principle, on the other hand, suggests structuring code in a way to ensure that a class is never forced to implement a function which is not essential for its purpose – a hand method for categorizing interfaces.

What is software architecture?

Software architecture works as a blueprint for a software system. It helps to manage the system’s complexity and sets up a communication/coordination mechanism among its components.

Software architecture is about defining a structured solution that meets the business and technical objectives, all the while optimizing issues like security or performance.

It’s already at this level that development teams need to make a set of decisions about the organization of the software development process, for example:

• Selecting the structural elements and their interfaces to make up the system,
• Defining how these elements will collaborate (behavior),
• Composing structural and behavioral elements into a larger subsystem,
• Architectural styles guiding the organization,
• Alignment of the architecture with key business objectives.

These decisions will have a massive impact on the performance, quality, and maintainability of the software. Ultimately, software architecture is a defining factor in the success of the final product.

The central goal of software architecture is identifying the requirements that will affect the application’s structure. Software architecture handles both functional and quality requirements, improving the overall quality and functionality of the system.

A well-developed architecture reduces the business risks associated with building a solution. It also closes the gap between the business and technical requirements. By realizing all scenarios and use cases, software architecture addresses the requirements of various stakeholders.

Software architecture and design: their relationship and critical differences

Software architecture shows the system’s structure and hides the implementation details, focusing on how the system components interact with one another. Software design, on the other hand, concentrates on the system’s implementation, often delving into considerable detail. Software design centers on the selection of algorithms and data structures, as well as the implementation details of every single component.

As expected, the concerns of software design and architecture tend to overlap. But instead of losing energy on defining rules for distinguishing them, it’s smarter to treat them as two parts of one process. Sometimes development teams make decisions that are more architectural during software design. On the other hand, it’s sometimes useful to concentrate on design a little more and see how it helps to realize the set architecture.

While architecture general contains design within its scope, the same cannot be said for design – in short, not all design is architectural in nature. It’s the job of the software architect to draw the line between software architecture and detailed design.

The current trends in software architecture point to the fact that design tends to evolve over time. A software architect can’t know everything upfront and provide a full system architecture. In general, the design develops during the implementation stages. As the system gets implemented, the software architect can learn from it and test it against the real-world requirements.

Conclusion

Software architecture and software design are rightly treated as two separate stages of the software development process. Architecture requires a high-level view and considerable experience. Software architects are usually team leaders with many years of experience. They have outstanding knowledge about battle-tested and innovative approaches that helps them make the best decisions in the planning phase.

If you’re looking to build a software product, you need a skilled software architect on board. And finding a professional with the right domain knowledge and experience can be challenging.

Team up with us to take advantage of top expertise in software architecture and design – our experts have plenty of experience in delivering high-quality software to companies across different industries.

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