a good and robust integration system cannot be separated from how the initial design of the system is selected and implemented. Therefore, integrating existing systems to become a large system that meets the needs of other connected systems requires full assessment and verification so that when the system is implemented, the necessary changes required in the future will be able to be accommodated seamlessly. This paper demonstrates an evaluation of a prototype of a data center system using a scenario-based architectural evaluation method called ATAM (Architecture Tradeoff Analysis Method), by analyzing the behavior exhibited by the developed system. The results of the analysis shows that some improvements are needed especially in terms of security, reliability and compliance in order to meet the relevant requirements of the robustness and the ease of doing system enhancement and maintenance.
Universitas Pendidikan Ganesha (Undiksha) has built various information systems especially for the needs of the implementation of academic activities such as teaching management, student academic activities, data management including lecturer, staff, research data and so forth. Specifically there are currently dozens of information systems that have operated within the Undiksha environment where each system is built separately and has a separated database system as well. Initially the systems were created with the aim to meet the need to facilitate processes that were done manually. As such, the systems were made focused on the needs in a field of study and mostly separated from the existence of other systems that could have an interconnected information among them. Moreover, some of the created systems were operated separately and they were useful only during the beginning of the system launching and then neglected due to the various problems of overlapping information found, and the information system needs further evaluation both in terms of its design consolidation and user experience. At the end of 2016, the Undiksha IT team proposes and designs a prospective system called Data Center (DC) to accommodate the needs of institutional accreditation so that information obtained from existing systems will be more organized and synchronized. Although many systems have been built, as observed there is no standard practice in applying an architectural system evaluation performed beforehand either at the design stage or upon the operation of the system.
The proposed centralized DC system needs to be developed well to integrate data from all supporting systems, so that duplication issues as well as problems due to the existence of various data structures can be reduced because the information contained will be the main source of overall academic activity in Undiksha. During the early development of the DC system, the Information Technology team at UPT-TIK Undiksha department has been exploring and designing a data warehouse server for the DC system using Enterprise Application Integration (EAI) technology that specifically implements a service-based framework called Enterprise Service Bus (ESB) .
While undertaking the enhancement of this system, a study has been conducted primarily in relation to the overall selection of the applied system architecture. When working on system development, human resources availability is also a critical determinant for completing and meeting the system requirements. This paper focuses more on how the choice of architecture is made on several options by prioritizing the needs of the system quality attributes by using a method called Architecture Tradeoff Analysis Method (ATAM).
ATAM is a well-known scenario-based approach system architecture evaluation method. In doing the evaluation, one has to consider a set of scenarios which focus on either the system non-functionality or the qualities exhibited by the system. ATAM has been a proven technique for systematically evaluating software architecture for fitness of purpose , . There have been many similar system architectures evaluated using the method such as done by Gambo et al. in , who examined a Health Information System and stated that addressing performance quality attribute among others is the most crucial. With ATAM approach, the authors show in the generation of the scenario based evaluation, performance issues were broken down into quality attributes for analysis. Other cases as in , the authors address security requirements evaluation for an SOE-based ecommerce system which optimized the existing SOA architecture solution with an incorporation of caching mechanism. Another case study has used ATAM and successfully evaluated and improved an online application as described in .
The evaluation result of this case study as obtained reveals an identified alternative system architectural as well as improvement approaches that has been taken.
This paper is structured as follows; Section I is the introduction, Section II provides a brief description about the evaluation method, ATAM, Section III describes an overview about the DC system and the evaluation approaches with the result obtained and Section IV draws conclusions.
ATAM has a goal to elicit and refine the architecture’s quality attributes whether the architectural design decisions have addressed the quality attribute requirements satisfactory . The quality attributes consist of various system responses such as performance, security, availability, flexibility and so forth. As also described in , ATAM uses architectural approaches instead of architectural styles. Architectural style at least consists of a set of component types, connector or interaction mechanism, and informal cost and benefit description. The summarized steps involved in ATAM are depicted in Figure 1.
ATAM consists of nine steps which can be categorized into four groups such as:
A. Presentation, which involves activities such as (1) Presenting ATAM. During this activity, describing the evaluation method to the system stakeholders is required which typically includes customer representatives, system architectural team, user representatives, administrators, developers, testers, integrators, etc. (2) Presenting Business Drivers. In this activity, the project manager needs to explain the business goal which motivates the development effort that will become the main architectural drivers for e.g. high availability, released time, system performance, security, etc. (3) Presenting Architecture. In this activity, the system architect needs to elaborate the proposed architecture which focuses on a solution to address the business drivers.