Service-Oriented Architecture and the Modular Approach to Functionality

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Service-oriented architecture, also known as SOA, uses discrete, reusable components that let developers take a modular approach to product design and eliminate monolithic software. SOA functionality tends to meet the needs of organizations that rely on repeat business functions. Instead of building a complete web application to fill a specific need, SOA can reuse components to speed up application development and avoid mistakes.

Whether you have consumer-facing products or your DevOps team builds products for internal use, SOA services could improve your workflows.

How Service-Oriented Architecture Works

The typical SOA framework relies on five horizontal layers:

  • Consumer interface
  • Business processes
  • Services
  • Service component
  • Operational systems

Your specific SOA framework might look a little different from the levels above. Regardless, understanding the roles they play should help you embrace SOA as an effective strategy for app development.

Each layer contains a number of architectural building blocks (ABBs), which are essential components designed to execute specific functions as needed.

Consumer Interface Layer

The consumer interface layer allows users to access the features they need. It’s important to note that the GUI interface separates users from the many SOA components and their functions. Separation might sound like a downside to SOA frameworks. In practice, however, it creates the appearance of seamless services. It also lets users set and save their preferences. The next time they come to the interface, it can greet them with customized features and design that make the component feel seamless and personal.

Business Processes Layer

Optimal business processes need to adapt quickly to changes in consumer demand and industry expectations. Before service-oriented architecture, most developers needed to embed business processes as core aspects of their applications. When expectations changed, DevOps teams had to scramble to rework apps.

Creating a separate business processes layer makes SOA more agile. Instead of putting the features necessary for business processes at the core of an app’s design, those features can sit independently between the services layer and consumers.

With this framework, evolving often means adding, replacing, or tweaking a few building blocks instead of rewriting large segments of software code.

Services Layer

SOA’s services layer includes components that fulfill critical functions, such as:

  • Access control
  • Policy management
  • Service clustering
  • Service runtime enablement
  • Service definition

Some of these capability categories need to perform multiple functions to do their jobs correctly. For example, the service runtime enablement capability category usually includes:

  • Service containers
  • Service interaction managers
  • The service registry
  • A quality-of-service status manager

Like other SOA layers, developers can alter, remove, or add components to keep up with the services layer’s evolving needs. If your company wants to add flexibility to its quality of service layer, it could update related components to reach its new objectives.

Service Component Layer

The service component layer contains the actual services that users want to access. Giving these components an independent layer separates technical business logic and IT needs from the user’s experience.

This layer has up to five types of ABBs:

  • Service realization and implementation
  • Service publication and exposure
  • Service deployment
  • Service invocation
  • Service binding

Every SOA layer does something critical to the user’s experience, but it’s fair to see this as the core of functionality. Without these essential SOA components, nothing would happen.

Operational Systems Layer

The operational systems layer includes the hardware and software necessary for SOA solutions to function. The layer has ABBs that manage service delivery, runtime environments, and virtualization and infrastructure services.

The operational systems layer is also where your SOA connects to other systems, including databases and legacy software. Digitalization is an ongoing process, so you might need to continue relying on some aspects of these systems while you transition your technologies.

You can learn more about the SOA layers from Open Group’s SOA Source Book.

The Difference Between Service-Oriented Architecture and Microservices

The SOA concept and microservices architecture have a lot in common. Perhaps most critically, they break monolithic and enterprise applications into small, self-contained building blocks. When you want to update software components, your developers don’t need to worry about how changing one feature could disrupt a huge library of dependencies. Both architectural styles leave room for ongoing development without disrupting business processes.

Service-oriented architecture differs from microservices in that it contains the code and data needed to complete a task. While microservices might need to ask other applications or features for data, SOA contains everything it needs. This approach means that SOA has even fewer dependencies than microservices, so you get loose coupling that requires very little communication between features.

Benefits of Using SOA

Service-oriented architecture demands a new approach to designing and implementing application features. DevOps teams have embraced it because it offers several benefits.

Related reading: Data Mesh Architecture: Understanding the Four Key Components


SOA doesn’t need a specific operating system, programming language, or file format. Like web services and other cloud computing concepts, SOA components can adapt to the user’s needs.

Your software development team can write components in practically all programming languages. Some of the most popular include:

  • Java
  • Python
  • Extensive Markup Language (XML)
  • Web Services Description Language (WSDL)

Anyone with access to your website or mobile application can potentially use your SOA components. However, you might choose to use an enterprise service bus (ESB) to simplify access and give your developers more control over how they coordinate components. Doing so provides a comprehensive service interface that makes independent services look like they coordinate with each other.

It doesn’t matter whether the user prefers Windows, Mac, Linux, or another operating system. Cloud computing functions independently of operating systems, making SOA architecture useful throughout your IT environment.

Reuse SaaS Components

You probably already have plenty of SaaS (Software-as-a-Service) components that you could add to your SOA software designs. You might also have vetted open-source components that you would like to reuse, especially if your audience already has experience with them.

You can incorporate the precise components you need into each user interface. You might think of it as cooking in a restaurant. You can use onions in multiple dishes. You don’t need to somehow reinvent the onion before you put it into a new recipe. That holds true with service-oriented architecture. The components you put together essentially make a recipe that serves a user’s specific need.

Improve Your Business Value by Evolving Quickly

Building large, monolithic software applications can take months or years. Over time, your competitors will release newer products, which could take away from your business value. You create opportunities for quicker adaptation when you adopt an SOA architectural pattern.

Since you only need to add new components to your service registry, you can shorten production times and stay ahead of competitors.

Shortening the DevOps process could also help you abide by the specifications of your service contracts. Perhaps a client’s service contract says that your product offers payment validation within five seconds. Changes in how consumers pay for products could influence how quickly your services work. Similarly, your payment processing could slow as your client attracts more customers. You don’t need to panic. Instead, you can add a new component that assists or replaces the earlier version. Now, you can meet your service contract specifications to avoid financial losses and maintain a positive brand reputation.


Service-oriented architecture has the potential for rapid scalability when user demand grows suddenly. How you approach this will depend on the specific situation. A cloud services provider like AWS, Microsoft Azure, or IBM will let you launch more server power to accommodate brief periods of robust activity.

If you need a long-term solution, check your communication protocol. TCP is usually the best option when the service provider and service consumer are connected to the same intranet. If users access the service via the internet, you can use HTTP. It doesn’t work as quickly, but it can use load balancing to assist scalability.

Other options include:

  • Java Message Service (JMS)
  • Apache ActiveMQ
  • Apache Thrift
  • Simple Object Access Protocol (SOAP)

Regardless, you get a great way to meet user demands as they increase and decrease. Additionally, you can use more than one protocol at a time. For example, you might rely on TCP for internal users while you connect external users to microservices via RESTful API.

Disadvantages of SOA

With so many benefits of SOA, why don’t all companies adopt it? Like all technologies, it has some potential disadvantages. Some of the most challenging barriers to success include:

  • Large financial investments can seem daunting as you transition to an SOA framework.
  • Loads can get very heavy as more people use the interface.
  • Response times can slow as loads increase.
  • Components often need to interact with each other, which can create a lot of messages that make management difficult.

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