For instance, in business scalability means the quality or ability of a business structure, system or model to maintain optimum performance with changes such as, increase or decrease in number of employees, workload, pressure, reduced or increased finances, etc.
This post though would be focusing on the importance of scalability in software development and design. So, to better grasp the importance of this component, we'd naturally start by defining software scalability.
While software scalability is important, it is not a neccesity is the software in question is not expected to expand it's base of operations in the future. That means, an unscalable software can run just fine.
However, if you expect the software to grow to accommodate changes such as more workload or more users, scalability should be a component of the software's design and development process.
Vertical scalability is also known as scaling up. It is not a very common form of scalability compared to horizontal scalability especially for software developed for enterprises.
In vertical scalability, the software would be able to scale up or maintain functionality while adapting to changes when more advanced hardware is added to the system. So, the initial version might work on a lower level hardware, but the updated version would require advanced hardware to function.
For instance, though this is not a really good example. The updated versions of WhatsApp do not install on any Android version lower than version 4.0.3.
Scaling up as I've stated earlier is not so common especially if you need the software to scale fast to accommodate changes such as increased users. The cost of buying advanced hardware to meet up with changes also comes into question.
For horizontal scalability on the other hand, the software would be able to grow while maintaining stability and functionality with more infrastructure. This factor has made horizontal scalability a favorite for Enterprise purposes. So, for the software to grow and accommodate changes, you would only need more infrastructure in the same level with the one already in use and the workload is spread across them.
More infrastructure can be extra storage devices, more or a bigger server, extra CPUs that are compatible with ones already in use. This kind of scalability is considerably less expensive when compared to scaling up.
Also, scaling out is faster when compared to scaling up since you do not have to move the software from one hard ware to another and begin the whole process all over again like the case is with scaling up.
Oh, horizontal scalability is also known as scaling out.
Scalability is essential for software such as websites and apps for businesses and organisations. Because there would definitely be more data or users with time added to the software's database. As such, it would be wise to make provisions and room to allow easy adaptability when such changes happen. It is also less expensive too, when compared to the cost of creating a new software to accommodate the growth of your business.
So, whether you are a business owner or developer if there is any chance that the software would grow in the future, ensure that it is scalable.