Andrew Duca – principal MES system architect, Honeywell Process Solutions, Phoenix, USA
Neil Freeman – principal consultant Mining and Metals, Honeywell Process Solutions, Perth, Australia
Siggy Drews – account executive Mining and Metals, Honeywell Process Solutions, Johannesburg, South Africa
Demystifying SOA for the process industry.
Keywords: [.NET, abstraction, architecture, business process, contract, decomposition, discovery, flexible, interface, IBM WebSphere, integration, ISA S95, manufacturing, MES, MIG, MIMOSA, OAGi, SAP NetWeaver, service, SOA, standards, use case, Web Services]
Service oriented architecture is an architectural style founded on the provision and consumption of services.
Abstract
Interfacing data between applications is always a problem for large manufacturing execution systems. This is gradually getting easier and more uniform especially with the emergence of de facto standards such as Microsoft’s Web Services. However, by just interfacing data, businesses are still locking themselves into solutions that are unwieldy by not providing the flexibility to modify the processes needed to keep pace with the business.
Service oriented architecture (SOA) is a methodology designed to provide interoperability between applications at service or business process level. This provides for more than just data interfacing in that the services that comprise applications are exposed and made available for integration. In this way not only data but business processes and workflow become explicit and released from within the confines of traditional monolithic applications. Hence business flexibility is enabled through ease of modifications to business processes and workflow empowering the process to keep pace with the business.
SOA has been a philosophy adopted by the commercial world for many years, however it is the ‘new’ buzword that is taking the process industries information systems by storm. This paper will provide an overview of what SOA is; why it is important to the process industries and what the value of adopting this technology is.
Background
There is a tremendous amount of literature and attention being generated about SOA today. It has penetrated the financial and telecommunications industries as well as many others and is starting to garner a lot of attention within the process industry. This paper will attempt to demystify what SOA is, why it is important, and how it helps to simplify the complexity of existing solutions and deployments.
Definition
Service oriented architecture is an architectural style founded on the provision and consumption of services. Practically speaking, a service is a software program that implements a useful and reusable unit of work that can be interacted with through a well-defined interface.
A key difference between SOA and other software architectural styles is that services are defined at an abstraction level relevant to the users of the service, while hiding the implementation details of the underlying service. Typically, services related to business functions like ‘Create Order’ or ‘Update Inventory’ rather than software functions such as inserting or updating records in a database. At this level, services can provide a common ground between the IT and the business requirements.
‘Services’ and ‘Web Services’ are often used interchangeably, and while it is true that most service oriented architectures are based on web services, services can be implemented and hosted in multiple environments. It is also important to note that many existing web services are not suitable for use in service oriented architectures, due to insufficient abstraction, poorly defined interfaces, or lack of support for relevant standards.
A service oriented architecture is broader than just simply services, it also includes the aggregation of services into higher order workflows, themselves services, that meet a specific business process need. Well architected SOAs exemplify a loose-coupling between services and the underlying operating system or supporting technologies to achieve a composition framework where business process or user interfaces can be customised, extended, or changed. A complete SOA includes the necessary infrastructure to support service composition to meet the requirements of end to end integration.
Continued on the web
For the complete article visit www.instrumentation.co.za/+C9206
For more information contact Siggy Drews, Honeywell Process Solutions, +27 (0)11 695 8138, [email protected], www.honeywell.co.za
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