Migration of a Chosen Architectural Pattern to Service Oriented ...

Chapter 4. Service Oriented Architecture 99by performing some predefined procedures, therefore a consideration how SOAdriven project affects them is also needed. Technology and big projects are thechallenge that have to be faced. Business level benefits can be translated topersonal perspective in following manner [46]:CEO – work of execution officer is supported by a clear strategy what enablesshort-term planning and reduction of budged for maintenance.Project Manager – an underlying infrastructure does not play so significantrole anymore and Manager can focus on functional aspects of a project that isalso supported by shorted iterations / project. The shortage can be achieved byparallel development of decoupled services and reduction of testing.Architect – Service Oriented Architecture is a kind of challenge that makeswork more interesting and helps develop creative thinking. Service driven approacheliminates also monolithicall infrastructure and supports creation of looselycoupled components what increases stability of the system.Developer – Fact that services are self contained entities reduces dependencies.This simplifies refactoring and testing. It is also easier to define requirements forsmall components with strict boundaries.ChallengesAlthough benefits brought by Service Oriented Architecture seems to be temptingbut as there is no smoke without fire, there are no pure benefits without challengesto be faced. Introduction of SOA is a challenge itself, especially when this approachwas not used in projects before. Each novelty causes resistance of people,especially when it requires additional overheads as SOA on initial phase. Theoverhead is associated mainly with transferring existing infrastructure to SOA[46].As a result, company has to reconsider relationship with vendors of standardsoftware and software infrastructure.However decoupling brings a lot of benefits, it appears as non trivial task thatrequires experienced requirement engineers and architects. Architects have also todesign their systems with service oriented structure in mind. A special attentionhas to be guaranteed for the most significant part of SOA -reuse. Designing highlyreusable components is very challenging task requiring open-minded thinking andof course previously mentioned experience which grows in importance because oflack of clear standardization. Although this deficit is slowly eliminated by SOAvendors who propose own perspectives (see 4.5)