6.1 Conclusions
This study implemented a selected module of PBS using a new approach of Software Engineering, namely the component-based Software Engineering. This implementation provides interoperability between two different systems of PBS with the access of a common module and avoids duplications for both systems. With this approach maintenance cost is expected to be reduced since components are designed to be independent.
Because of the fact that PBS has hybrid architecture in terms of its network infrastructure and software, PBS runs on two different network segments; one of them is TRANSPOL infrastructure extended all around Turkey and another one is Personnel intranet extended on only Personnel Department network. These two networks are separated with firewall by defining Personnel Department network as VPN (Virtual Private Network). In the first segment, PBS/Outside system is run while PBS/Inside is run on the other. Software architectures and environments are also different for these systems. Since most of the applications of PBS have different unique characteristics for each system, there seems no exploitation to build two different systems based on different business logics and software architectures.
However, despite this, some exceptional, complicated, and common business applications cannot be ignored. So these types of applications are not skipped, and distributed component architecture is accepted in PBS. This architecture is used with a new methodological approach, that is, component-based software engineering.
Service Calculation application is a necessity for PBS through both PBS/Outside system and PBS/Inside system. Because of its complicated characteristic, there will be confusion with the changes of its algorithm and structure. To prevent these
contaminations, it is decided to build these types of applications with distributed component technology, and EJB 2.0 is chosen for implementation. It is believed the more suitable development process model is COSE Process Model since its phases are designed for component-oriented approach.
Two GUIs allow users to access Service Calculation application through their various architectures and technologies. The GUIs, mentioned before can call every required function of Service Calculation application, using a remote interface of Service Calculation component. This ability means that interoperability is reached in this study.
Consequently, now the Service Calculation package is deployed on component container of PBS as a first EJB package. At the time of writing, it is being accessed by inside users of the system and tested. After providing satisfaction regarding integrity of calculations then it will be introduced to inside and outside users officially.
6.2 Suggestions
Component-based approach can increase software-building performance with effective component repository. If an organization does not consider importance of component repository, it becomes garbage-like, in the course of time. To avoid this, the component specification phase of COSE Process Model should be better considered and followed in detail and with sufficient care. If organizations like Personnel Department think to develop its repository in time, special care is especially needed in component specification. Shortly, this approach enforces first three phases, that is, specification, decomposition and component specification, to perform regularly. When they are performed as they should be, the rest works spontaneously.
COSE process model encourages an organization to develop a component repository for its business domain. This study will lead PBS to develop its similar modules within this methodology in the course of time.
For industry, there is a need for some bridges between component architectures to provide maximum profit from runtime-reusability. More effective connector technologies, based on standards, must be developed and consequently the system designers will not have to write code to glue various components that are running on various frameworks.
As a consequence, although it is inevitable due to reasons (interoperability) mentioned in this study, component-based approach needs more standardized methods to improve its effectiveness especially in practice.
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APPENDIX I