Service implementation technologies

Service implementation technologies

1. 3 types of software reuse

   • Application system reuse Component reuse object and function reuse

2. Benefits of software reuse

   • Increased dependability reduced process risk effective use of specialists standard compliance accelerated development

3. Problems with software reuse

   • -Increased maintenance -lack of tool support not-invented here syndrome -creating, maintaining and using a component library -Finding, understanding, and adapting reusable components

4. Reuse landscape

   • The reuse landscape covers many of the areas software reuse can be used. Such as: -ERP systems -Program generators -COTS integrations -Design patterns -Software products lines

5. Reuse planning factors

   • -May take a long time - schedule -Software lifetime, will it meet customer expectations in the future? -skills and experience of development team

6. Application frameworks

   • are large entities that can be reused
     • made up of abstract and concrete classes
       • 3 different types of framework classes -system infrastructure framework -middleware integration frameworks -enterprise application frameworks

7. software product lines

   • these are application families sahre common architecture and components  adaptation may involve adding new components -selecting from a library of existing components -modifying componenets to meet new requirements
   • usually owned by the same organisation

8. Product line specialisation

   • -Platform specialisation -environment specialisation -functional specialisation -process specialisation

9. COTS

   • commercial off the shelf product (COTS) is a software system than can be adapted for different customers without changing the source code.  for example, microsoft outlook.  allows it to be tailored to customer specific needs, therefore may be cost effective. cots can therefore be reused in multiple environments. 
   • problems
     • -lack of expertise to support system development to specific business requirements -business requirements may have to be adapted to fit the functionality of the COTS product -can be a difficult process to choose the right COTS system
   • COTS integrated systems
     • an intergrated system use 2 or more cots products when 1 cots product does not meet the need. an example such as word and pdf converter.

10. ERP

    • -enterprise resource planning -supports common business processes such as ordering, invoicing, manufacturing etc. -includes different modules to support business functions -a large database for the erp system

11. SAS (software as a service)

    • -software distrobution model -applications hosted by a vendor  -software made available over a network like the internet
    • SOA (Service-oriented architecture)
      • -A means of developing distributed systems where the components are stand-alone services -may execute on different computers -standard protocals have been developed to support cross platform functionality. 
      • Benefits of SOA
        • – It allows flexibility as services can be provided locally or outsourced to external providers – Services are language-independent – Investment in legacy systems can be preserved – SOA allows different platforms and implementation technologies that may be used in different parts of an organisation to inter-operate – Building applications based on services allows companies and other organisations to cooperate and make use of each other’s business functions

12. Interface design stages

    • -Logical interface design -Message design -WSDL description

13. Legacy system services