Technical and commercial data - mutual influence

The linkage of cost estimation for an infrastructure project and the technical data can be highlighted by the simple example for a road construction. To estimate the cost for the road construction it is necessary to calculate the material which has to be moved. A change in the alignment of the road will force new construction methods and therefore the use of different machines as assumed in a previous stage of estimation. The amount of facilities which have to be placed along the new road will change as well. A first road alignment proposal which can be clearly fixed within a certain corridor by use of GIS functions will limit the variations in the cost estimation.

7.3.4.1 Metadata in tender phase

Metadata in tender phase is all information about the data which was used to prepare the tender documents. This kind of metadata is relevant in the case of a positive contract award and as an example for tender preparation in following similar projects.

For construction phase information about budgeting for specific construction items can be found easily by searching in such a tender metadata catalogue. A good introduction for enterprise relevance of GIS Metadata and examples for the content can be found in [BRUNSCHOT].

7.3.4.2 Dissemination aspects using Map Server Technologies during Tender preparation – Interoperability

Infrastructure projects distinguish themselves because of their geographic expansion, especially roads or railways, dams and access, integrated facilities like airports or harbours. The information density is determined by overviews on small scale maps and by detailed drawings on large scale maps. The information content of the maps and drawings is growing with the decreasing of the scale number. The numbers of participants involved in the preparation of the tender documents are dependant on the complexity of the infrastructure project; therefore a dissemination of the information with current simple information techniques is preferable.

Instead of printing all information according to the number of participants the tasks can be shifted to the user by using the map server technology. The user can search and print the information he needs for his workflow. Another advantage is that a structure can be established in a way that the geographic location of the information is always present, so that decisions reflecting the information can be made with awareness about the vicinity of the information’s location. The linkage of features, which are then presented in the central map server environment, with technical databases has influence in the workflow in the departments and will keep the data consistent.

A summary of advantages of a centralized database management system on construction sites, which would be an advantageous for a tender database as well, according to [HENDRICKSON, Chapter 14.7] are:

- Reduced redundancy - Improved availability - Reduced inconsistency - Enforced data security

The map server technology is based on databases and can serve the above mentioned items. Additionally specific files – like raster data and vendor specific files - can be loaded into the environment. The map server technology is also based on a network communication thus there is no question about the availability, consistency. The data security will be handled by the network administration and the database functionality.

7.3.4.3 Equivalent developments for building business (Model Server) Interoperability (IFC)

The International Alliance for Interoperability (IAI) has started a project which deals with the business needs in the Architectural Engineering and Construction world and the GIS world. The project is called Industry Foundation Classes for GIS (IFG). The recognition of significant overlaps between both worlds initiated the project. Buildings are constructed facilities that are placed within the world. These two virtual worlds - AEC and GIS - share the concept of lifecycle based information provision and will have similar approaches to portfolio and capital project development, design processes, costing and cost management, asset management, maintenance and other factors. As well the systems share the interest in system development for the purposes of dissemination systems. While GIS signs for the general utility systems within regional infrastructure, AEC are opposed to the local distribution mechanism applied in AEC.

The approach for the both systems definition is likely to be notably similar.

The mutual benefits for the project with the GIS interest provided to IFC are given in [IFG-PROJECT]:

GIS provides to AEC

- global location through map information provision

- regional information relevant to building planning and provision - utility information relevant to the services within a building - risk information from nearby geographical features

AEC provides to GIS

- facility to be able to see a building and component entities as real objects and not just illustrations pasted onto a map

- real building data for security and emergency services

The interesting items outside of this project for a construction company are the provision of GIS information through IFC by leveraging developments that have occurred within IAI (for AEC community) and ISO TC 211 (for GIS community), the definition of interfaces between AEC world and the GIS world (interoperability and collaboration strategies) and the definition of a model development and mapping approaches that build upon GIS developments within the ISO TC 211.

In detail the demonstration provision scope for GIS to AEC in the IC-3 Project are:

- semantic identification of a ‘site’;

- the geometry of a site in the form of a simple digital terrain model;

- specification of a site boundary;

- Provision of additional properties within property sets as deemed necessary.

In detail the demonstration provision scope for AEC to GIS in the IC-3 Project are:

- semantic identification of a building and the building elements that are relevant for representation within GIS including, amongst others, building, wall, window, door, opening;

- primary elements of the building spatial structure elements concerned - provision of additional properties within property sets as deemed necessary The advantage of the integration of both worlds can be described with a reduced effort for construction interface related coordination. Several systems (building element, HVAC-, electrical-, sanitary-, lightning, structural, furniture, spaces, zones, compartments, manholes, grids, draughting, sanitary, etc) can be integrated into a common system. A discussion about connection points can be done on the same database. (Loading IFC data into IFC-Viewer see figure 7.3.4.3a).

Figure 7.3.4.3a Semantic information import from Architectural Desktop (ADT 3.3) to IFC-Viewer from Data Design System (DDS); Part of Gate B of Düsseldorf Airport.

Further studies related to the integration of Geo-object can be found on the web page of Forschungszentrum Karlsruhe Institut für Angewandte Informatik;

http://www.iai.fzk.de/projekte/geoinf/index.html. The application QUASY deals with the integration of building models (IFC) in GIS. Another source of information is the SIG 3D a working group of the Geo- Data Infrastructure initiative of North Rhine Westphalia

(SIG 3D GDI NRW) and the Institute for Cartography and Geoinformation from the University of Bonn. The SIG 3D group is discussing the level of details (LoD0 – LoD4) and the realization by unified modelling language (UML) for city models [KNOSPE].

The Institute for Cartography and Geoinformation is dealing with the CityGML which implementation is based on GML3. The class taxonomy distinguishes between buildings and other man-made artefacts, vegetation objects, water bodies, and transportation facilities like streets and railways. Spatial as well as semantic properties are structured in five consecutive levels of detail, where LoD0 defines a coarse regional model and the most detailed LoD4 comprises building interiors and respective indoor features [KOLBE].