| Summary: The lack of local and National level Spatial Data Infrastructures (SDI) in Turkey is a major issue concerning the nationwide interoperability. Building a National level SDI (NSDI) is a formidable task. It will require a transformation of involved institutions for the required functioning of NSDI. The required is a technological and institutional transformation. This work is on a dimension of the technological transformation of Land Title and Cadastre (LTC), one of the main data suppliers in envisioned Turkish NSDI. This is the dimension of transforming the LTC data services to a structure required by Service Oriented Architecture (SOA), a technological infrastructure alternative for NSDI. This task requires a Services Oriented Analysis and Design (SOAD) to determine the Web Services that would be served by LTC for both internal and external use. An extensive literature search was first performed to carry out a SOAD for the task. The literature search, however, has shown that there was neither a SOAD methodology nor an applicable approach in place. The major problem in SOAD is to determine the granularity of services. Despite the countless resources on the subject, there was no concrete proposal for the solution. This has been the main problem to be dealt with in this thesis. Following an extensive requirements analysis for the LTC services in Turkey, a SOAD methodology has been proposed. The methodology is largely based on Object Oriented Analysis and Design (OOAD) Methodologies. The proposed methodology is a major contribution in the area. The other main contribution of this thesis is the performance analysis of Web services in the context of both the feasibility of cadastral services and the granularity of the services. The performance analysis which was carried out by simulation models has shown that “fine-grained” services cause performance losses with respect to “coarse-grained” services and therefore services should be designed in proper granularity level. The performance analysis has also shown performance gains in the case of “distributed” LTC service provision with respect to the current “central” provision.
Keywords: Service Oriented Architecture, Service Oriented Analysis and Design, Granularity of Services, Cadastral Web services, Web services performance, National Spatial Data Infrastructure.
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