One of the most common, and efficient, models deployed by enterprises is the Layered Architecture, also called the n-tiered pattern. It packs similar components together in a horizontal manner and is self-independent. What does that mean?
It implies that the layers of the model are interconnected to each other but not interdependent. Similar components stay at the same level allowing the layers to be separated inadvertently based on the nature of the code. It is this isolation, that lends the software layers an independent nature.
Consider an instance, wherein you’d want to switch from an Oracle database to an SQL. This shift may cause you to upend the database layer but will not have a domino effect on any other layer.
Evidently, it serves a challenge for an enterprise software architect to create layers that separate from each other. Nevertheless, since the roles of each layer are clearly distinct, it accredits this software development architecture the following qualities:
- It is easily maintainable as enterprise software developers with limited, or should we say pertinent, knowledge can be assigned to operate on a single layer.
- You can test changes in layers separately from each other.
- Upgraded versions of the software can be implemented effortlessly.
The flow of code is top-down, meaning it enters the presentation layer first and trickles down to the bottom-most layer that is the database layer. Each layer has a designated task based on the nature of the components it preserves. These could be checking the consistency of values within the code or reformatting the code altogether.
Refactoring – a key – way to lower frontend maintenance cost is a software development process by which developers change the internal shape and size of the code. They do it without affecting its external attributes can also be carried out in an n-tiered model.
This software development architecture can be customized to add layers to the presentation, business, persistence, and database levels. Such a model is called a Hybrid Layered architecture.
- Amongst the various types of software architecture, the layered variant suits enterprises that don’t want to go overboard with experimenting and want to stick to the traditional software architecture design patterns.
- Testing components become relatively easier as inter-dependencies are negligible in this format of software development engineering.
- Considering many software frameworks were built with the backdrop of an n-tiered structure, applications built with them, as a result, happen to be in the layered format as well.
- Larger applications tend to be resource-intensive if based on this format, therefore for such projects, it is advised to overlook the layered pattern.
- Although the layers are independent, yet the entire version of the software is installed as a single unit. Therefore, even if you update a single layer, you would have to re-install the entire apparatus all over again.
- Such systems are not scalable due to the coupling between the layers.
The Layered architecture pattern suits the niche of LOB i.e. Line of Business Applications. These are applications that are essential to the functioning of the business itself. For instance, the accounts department of an organization needs software such as QuickBooks, Xero, Sage or Wave Accounting for keeping financial data.
Similarly, the marketing team would demand a customer relationship management software slash tool to help them cope with the volume of interactions. In short, applications that do more than just CRUD (create, read, update, and delete) operations are suited to the layered architecture pattern.