What is a Service-Oriented Architecture?
The Service-Oriented Architecture (SOA) software development model allows organisations to create applications using cross-platform and cross-language communication between their system’s various IT service components. In SOA, ‘service’ is an independent software unit designed to perform a specific task. An SOA helps different services communicate via a loosely coupled system to transfer information, coordinate processes and ultimately deliver higher-value IT services.
‘Loose coupling’ refers to the design principle of creating components (services) that are independent and have minimal dependencies on other elements within the system. The client is largely technically independent, can communicate with multiple different services, and acts as a service for other (superordinate) clients.
This interplay of these orchestrated and, in some instances, cascaded calls to the various services allows the many individual components in a service-oriented architecture to fulfil complex requirements without being technically dependent on other components.
Why do I need SOA and how it is implemented?
A service-oriented architecture alleviates three key pain points, each related to a specific stage in the application deployment process.
Firstly, processes or software components can be structured as services that are only connected to the applications as needed. The services are, therefore, designed to be easy to use for developers looking to create technically uniform applications.
Next, an SOA defines the provision of existing services and regulates their capabilities. It also clearly defines associated interfaces (APIs) and exchanged data structures. Again, the services are published so that developers can easily integrate them into applications.
Finally, a service-oriented architecture regulates access security, data protection and system control considerations as needed. In essence, SOA focuses on the security of the individual IT architecture components, the identity and authentication mechanisms associated with these units, and the security of the intercommunication paths.
A service-oriented architecture aligns with an IT ‘service concept’ or ‘service model’. In this system or IT infrastructure, processes are implemented as software services. They are accessed via strictly defined Application Program Interfaces (APIs) connected to applications through dynamic service orchestration.
What challenges can arise with SOA?
The SOA architecture acts as a hub for handling business processes. However, companies should consider several key points before proceeding with this approach.
Increased number of interfaces
SOA’s underlying principle of loose coupling increases the interfaces required within an IT service. The additional processing steps at the internal transfer points also make for longer execution times. Therefore, any internal transfer points must be performance-optimised to prevent this.
Careful technical planning
To ensure the individual components are reusable, the individual services and interface concepts within a service-oriented architecture must be carefully planned from a technical and functional perspective. Companies should also consider the technical research and level of detail needed to define all requirements. This can initially take up a substantial amount of IT team resources, so there must be a firm commitment and willingness to invest.
Complex management
Once implemented, it can be quite complicated to administer and operate services within a service-oriented architecture. This is, in part, also due to the degree of abstraction. In addition, the large number of messages exchanged during these processes can make monitoring time-consuming. The way the SOA is structured simplifies local, module-by-module error analysis due to smaller software units. However, some errors may be difficult to analyse if they stem from orchestration issues or asynchronous calls (e.g. deadlock situations, cross-module transactions, race conditions). Mature error-handling processes and well-founded log analysis mechanisms are, therefore, key.
Validation requirements
To add the desired value, input parameters are validated in a multi-layered approach for each interaction between services. These checks can affect the performance of a service-oriented architecture and increase load and response times.
What are the commercial benefits of SOA?
As an IT infrastructure architecture, SOA offers more flexibility, centralised services and demand-driven deployment than monolithic systems.
Interoperability and scalability
The benefits of SOA include high interoperability, as the technical standards are compatible with different applications and services. SOA also makes it easier to scale existing applications and cheaper to develop business applications by reusing service components.
Company-compliant automation of business processes
SOA utilises a common procedure call model in structured programming and standardises the way business processes are automated and used. It is implemented and integrated per IT security requirements and applicable company guidelines.
Time and cost savings
In an SOA architecture, internal and external business processes, such as those for customers and business partners, are created from pre-coded service components. By relying on existing services, companies not only save time but also cut costs significantly. Moreover, pre-programmed components accelerate innovation to a greater extent, as existing progress can be built upon more quickly.
Fostering expertise within the company
In a service-oriented architecture, essential services can be accessed centrally, so employees have easier access to important information and can improve their business process knowledge. They see the ‘bigger picture’ as well as the factors that impact their department. Therefore, it is important to consider managing and administering permissions for classified data from the beginning of the SOA design process.
