Key Principles for Successful Software Design

To design good software, much like anything, you need to understand the rules that others have discovered and found useful. It’s a matter of trial and error. Surely, there will always be room to grow. However, a good set of software design principles can help you create great, workable, and user-friendly software. Read on to learn these rules of software design. 

What are Software Design Principles?

Software design principles are guidelines that ensure your software is of good quality, works well, and can be edited and extended with ease. They may overlap and vary depending on the types of software design you are undertaking. Of course, there are exceptions, but it is crucial to know the base. 

Basic Software Engineering Design Principles 

Remember, these rules are not set in stone. Still, bear them in mind during the software design process to avoid mishaps and mistakes.

Minimize Coupling

When you have a system where various aspects, such as packages, modules, and files, are connected, there is more room for wider problems when one thing breaks. We call these connections coupling. Reduce it as much as possible by making parts independent. 

Follow the Uniformity Principle

The uniformity principle is one of the noteworthy object-oriented design principles. It means that your design should follow the same logic everywhere, and you deal with comparable issues in the same way throughout. It makes the process easier – instead of creating different solutions for similar problems, which will require more time and effort. 

Be Agile

Your system will no doubt change over time. Adopting any changes should be simple, so you won’t require a whole redesign. It may sound simple, but it’s a mistake many make.

Consider Portability

Your software’s usability on different platforms and devices significantly impacts its success. Think of it in advance. If you know that people will use your apps across different devices, consider making them portable.

Reduce Intellectual Distance

The term intellectual distance describes the stretch between the real world and the software solution to the problem. Aim at reducing it and making the solution mimic the real world as much as possible. 

Use what Exists

You don’t have to create each and every part of your software from scratch. A wealth of existing tools, frameworks, and other instruments can be incorporated into your software. Use them, as they can save you time and are likely to work well and be sufficiently tested. 

Review Regularly

Your design should be regularly tested and reviewed in a world of constantly changing tech. Otherwise, you will struggle to identify and remedy any issues. 

SOLID Principles

Aside from these basic software design concepts, some other key rules are important to follow. SOLID Principles are a good set of object-oriented design principles to adhere to. There are five parts of the SOLID Principles, which outline five key software engineering design principles. 

1. Single Responsibility Principle (SRP)

This design principle means that each class should have a single purpose and that there should be no more than one reason for a class to change. Each class is responsible only for its own class; there shouldn’t be overlap or more than one responsibility. If you need two responsibilities, you need to split them into two classes. 

2. Open/Closed Principle (OCP)

This principle claims software entities of any kind should be open to extension. However, they should be closed for modification. The ‘open’ aspect means that an existing code can and should be extended to introduce functionality. The ‘closed’ aspect means that when some module is tested, there should be no changes to an existing code unless to fix bugs. 

3. Liskov Substitution Principle (LSP)

This principle holds that functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it. In other words, objects that are part of a superclass should be replaceable with objects of their subclasses without breaking the application.

4. Interface Segregation Principle (ISP)

This principle is that clients should not be exposed to methods they don’t need in the interface. You should break up interfaces into smaller ones to fully satisfy your client’s needs. 

 5. Dependency Inversion Principle (DIP)

Let’s split this one into two parts: 

1. High-level modules should not depend upon low-level modules. Both should depend upon abstractions.
2. Abstractions should not depend upon details. Details should depend upon abstractions

In other terms, higher-level complex modules should not be affected by lower-level ones. All levels of modules rely on abstractions. If you follow the other SOLID principles, you should already follow this principle. 

Pareto Principle

You may have already heard of this one, as the Pareto Principle has many uses. Generally, it refers to the idea that 80% of all effects come from 20% of causes. In terms of design, this has several important implications: 

• 80% of the value, regardless of how we measure this, is in 20% of the requirements. 
• Users will work mainly with 20% of the tools available to them. Focus your energy on this area. 
• Errors and bottlenecks will generally come from 20% of the design. This means when you encounter a problem, you only need to fix around 20%, not redo everything. 

DRY Principle

The DRY acronym means: Don’t Repeat Yourself. Each and every piece of knowledge, as in software patterns, must have a single and unambiguous role. There is no need for repetition, and everything must play its part. 

The benefit of adhering to this principle is that changing one part doesn’t require changing other parts. Just focus on the one isolated area. 

KISS Principle

This abbreviation stands for Keep It Simple, Stupid! The term originates in the US Navy but can be used as one of the main object-oriented design principles to work with. 

It is quite straightforward and means that you should always attempt to avoid complexity when designing. It makes any later changes much easier to implement, will reduce the risk of bugs, and provide a better user experience. 

YAGNI Principle

Another easy-sounding principle is YAGNI: You Ain’t Gonna Need It. Let’s put it this way: you should only ever put what you need into your design. Never add anything you don’t need yet. It will make things work considerably smoother. 

Principle of Least Surprise

This crucial design principle of software engineering means that you need to ensure that the user is not surprised. When designing software, provide what is expected, and ensure it works as expected. 

Why are Software Design Principles important?

Following all of these principles can help your software work better, meet industry standards, and generally make it easier to change without causing massive system issues. Without these principles, you risk ending up with poor-quality software, resulting in constant fixes and can cause wasting time and money. 

How we can help

Following all the software design principles may be difficult and overwhelming, but it’s essential to do so for the sake of quality. Our experienced team at Fireart studio can help you design your software to ensure it adheres to the key principles. Get in touch to see how we can help!

Update: 2022-04-19