Question

SOA Case Study: Retail company, shopOnline, with an online web store and 900 retail stores, has the following characteristics: • Strategic objective: become the most profitable retailer in the industry through aggressive growth with minimal risk • Delivering a unique, seamless, cross channel experience. • Being the first to offer popular products that match customer desires. • Capabilities needed according to Business Process Analysis: – share consistent product information across multiple channels. – quickly and accurately incorporate new products. – 24h availability for product purchase and delivery. – sell services associated with products • Two primary initiatives: – Online-to-store, multi-channel initiative: consistent customer experience across multiple channels (Web, retail stores, and catalogues) – Product information management, new product introduction initiative: central management of information about products and focus on data required to market and sell products through one or more distribution channels *This case study has been created based on some business cases. a. If you are going to use an SOA based design to realize strategic objectives, discuss the SOA Architectural Principles that will be applied to your design. [7 Marks] b. Discuss the possible reference SOA based architecture using ESB. Please present an architectural diagram as your discussion reference.

Answer 1

Service-oriented architecture :

Service-oriented architecture (SOA) is a style of software design where services are provided to the other components by application components, through a communication protocol over a network. A SOA service is a discrete unit of functionality that can be accessed remotely and acted upon and updated independently, such as retrieving a credit card statement online. SOA is also intended to be independent of vendors, products and technologies.

A service has four properties according to one of many definitions of SOA:

1. It logically represents a business activity with a specified outcome.
2. It is self-contained.
3. It is a black box for its consumers, meaning the consumer does not have to be aware of the service's inner workings.
4. It may consist of other underlying services.

Different services can be used in conjunction to provide the functionality of a large software application,a principle SOA shares with modular programming. Service-oriented architecture integrates distributed, separately maintained and deployed software components. It is enabled by technologies and standards that facilitate components' communication and cooperation over a network, especially over an IP network.

  SOA is related to the idea of an application programming interface (API), an interface or communication protocol between different parts of a computer program intended to simplify the implementation and maintenance of software. An API can be thought of as the service, and the SOA the architecture that allows the service to operate.

There are 9 Principles Of Soa Design:

Service-oriented Architecture (SOA) is as simple as can be. There are 9 design principles to keep in mind when designing a SOA service:

• Standardized Service Contract:
  Services adhere to a service-description.
  
• Loose Coupling:
  Services minimize dependencies on each other.
  
• Service Abstraction:
  Services hide the logic they encapsulate from the outside world.
• Service Reusability:
  Logic is divided into services with the intent of maximizing reuse.
• Service Autonomy :
  Services should have control over the logic they encapsulate.
• Service Statelessness:
  Ideally, services should be stateless.
• 
• Service Discoverability:
  Services can be discovered (usually in a service registry).
• 
• Service Composability:
  Services break big problems into little problems.
• 
• Service Interoperability :
  Services should use standards that allow diverse subscribers to use the service. This is considered so obvious these days that it is often dropped as a principle.
• 

Integrating business processes :

Service Oriented Architecture (SOA) is a framework for integrating business processes and supporting IT infrastructure as secure, standardized components-services-that can be reused and combined to address changing business priorities. Services are the building blocks of SOA and new applications can be constructed through consuming these services and orchestrating services within a business process. In SOA, services map to the business functions that are identified during business process analysis. Upon a successful implementation of SOA, the enterprise gain benefit by reducing development time, utilizing flexible and responsive application structure, and following dynamic connectivity of application logics between business partners. This paper presents SOA reference architecture blueprint as the building blocks of SOA which is services, service components and flows that together support enterprise business processes and the business goals.

Logical View of ESB in Integration Layer