4.1 IT Architecture
Each subsystem in the integrated metadata system has a similar architecture: a database, two Web applications (one for consultation and the other for management) and a view that provides metadata to be reused by other systems.
Fig. 14. IT Architecture
Management was designed to be decentralised with central coordination. The management application therefore implements two profiles: the subsystem manager and the survey manager. There is a generic profile for consultation.
4.2 Metadata Management Tools
The subsystem management applications in the integrated statistical metadata system were developed with the same computer infrastructures as those supporting all the SP's information systems.
The tools at users' disposal are:
- The IIS servers and databases using Microsoft operating systems.
The network architecture is based on open protocols and industrial standards and is comprised of local area networks (LAN) and wide area networks (WAN).
The applications supporting the metadata system are Web applications developed with the ".NET" platform. All the subsystems have a bilingual consultation application and a management application.
The huge amount of information produced or collected into the system requires an appropriately sized database. The associated databases (relational databases) are developed in Microsoft SQL Server so that it is easier to integrate with the production and dissemination systems and the data warehouse.
Fig. 15. Servers
4.3 Standards and formats
The standard formats used are Excel, CSV and PDF.
4.4 Version control and revisions
The metadata are not static and change very fast due to modifications, for example, in concepts, classifications, revisions, new business rules, new methods, among others. As a result, there are "in use" and "not in use" versions of the entities in the integrated statistical metadata system which has to be created, verified and controlled. The versions are managed strictly by the managers of each subsystem, as already mentioned, following the rules governing each subsystem and obeying the rules of integrity. The subsystems are systematically revised in order to check the existing functionalities and ensure the ongoing implementation of improvements in usability and flexibility.
4.5 Outsourcing versus in-house development
The metadata system has been developed and implemented almost exclusively by in-house specialists. The reasons for this decision were:
- The existence of resources with good technical training;
- Good in-house knowledge of our statistics;
- The reduction in costs of undertaking the project;
- Assurance of continuous system maintenance.
Only the prototype system for consulting and managing the methodological document (as we mentioned before) was developed under an agreement with a university. The final version of the methodological documentation system that is expected to replace the prototype will begin to be developed later in 2008.