BIM Tools Overview Target group- and process-oriented examination of free BIM tools Steffen Wallner1, Petra von Both2 1,2Karlsruhe Institute of Technology - Department Building Lifecycle Management 1,2{steffen.wallner| petra.both}@kit.edu In Germany, 90% of architectural and engineering companies employ less than 10 employees. The profit generated there is often insufficient to legally exploit the cost-intensive BIM software solutions of IT companies. This is one reason why the BIM method is not widespread in Germany. In the context of BIM, there are free-to-use tools that are either developed in research and open source projects or also offered by IT companies. Within the scope of this research project, such tools were evaluated and assigned to BIM processes. The results are published on a website and the companies concerned can use these to extend their own BIM competence. Keywords: BIM survey, open source, AEC, tools, usage sceanrio, evaluation INTRODUCTION Nordic countries in terms of the implementation of The application of integral planning methods re- this BIM methodology. There are also deficits in com- quires a high degree of cooperation and integra- parison to the global trend. It is proved that the tion. This applies to both actors and competences, as method is suitable and both the public sector and the well as information and tools. In order to ensure an political side see its necessity (Koggelmann 2013). efficient process-oriented application of integrated However, with the exception of some pilot projects, planning and optimization tools, the approach of the impact is still limited and the method is rarely model-based planning (Building Information Mod- used in smaller building projects. eling BIM) has already proven to be a purposeful The reasons for this are, among other things, the method with great potentials (Both 2011). A virtual small-scale corporate structures in Germany and the semantic building model forms the basis of this in- relatively high-priced structure of commercial BIM tegrative approach, which provides the participating software solutions. Because of this, they are hardly stakeholders with building information throughout accessible to smaller companies (Braun 2015). Inad- the entire lifecycle. It also serves as the information equate technical interfaces and the lack of quality of basis for cooperative team, simulation and optimiza- exchanged BIM models hamper model-based collab- tion processes within the planning process. oration with other companies and lead to loss of ef- However, current surveys reveal (Both 2013) that ficiency. Especially for the small companies in the the German construction industry, is far behind the planning and construction process, which are forced BIM - Volume 1 - eCAADe 35 | 137 to cooperate strongly with partners, the question A Wiki system has been set up in the work prepa- arises: Which tools are available to support these pro- ration. Above all, the research was efficiently docu- cesses at reasonable costs? mented. It turns out that by far more sources had Small companies in particular benefit from the to be searched than free tools were found. The use cooperative and cross-company processing of virtual of the Wiki system prevented redundant searches. A building models. An improvement in the situation of version management system was also used to docu- this group of companies is expected to lead to a qual- ment the progress of the project. ity gain in the overall BIM process chain. The BIM processes have been researched in the Research projects as well as IT companies have current literature, BIM guidelines and standards. An developed various freely available or open source important document in this context was the Devliv- based BIM tools, which seem to offer potentials for a ery Manual (Wix 2010). Although it was not possi- wide range of applications. Access to such free and ble to derive relevant processes from this, it under- cost-effective BIM tools can create competitive ad- lined that the data exchange is essential for every vantages for small companies even in international BIM process. Other sources such as the BIM Guide- competition. lines for Germany (Egger 2013), the BIM Reference However, the relevant target group in the con- Process, and (Scherer 2014), (Tautsching 2014), (Bor- struction industry often does not know these tools rmann 2015), (Hauschild 2010), (Hausknecht 2016) because they have often been developed in other provide arguments for BIM by showing potentials contexts and their usability has so far hardly been and objectives. However, there were no practical us- evaluated. age scenarios, which could be applied directly to the In an one-year research project at the Depart- target group. The BIM reference process was too ex- ment of Building Lifecycle Management at the KIT, tensive. Furthermore, the document does not de- existing free and open source BIM tools were ex- scribe any BIM processes in detail, which require a amined and evaluated. The project and a summary concrete use of tools. The usage scenarios finally of the results are described in this paper. First, we used were based on the suggestions of (Hausknecht give an overview of the project. As we employ us- 2016). Six scenarios were developed and formalized age scenarios to classify the tools into BIM processes, in the BPMN notation. Later, the tools found could be we describe one of these scenarios as an example. assigned to the activities in the BPMN notation, see We briefly describe the investigated BIM tools and Figure 1. explain the evaluation criteria. We then summarize The search for the tools was partly carried out general statements about the quality and the avail- parallel to the development of the usage scenarios. ability of free tools and how we made the results pub- This was necessary in order to be able to estimate licly available. The paper closes with an outlook. which usage scenarios are relevant at all. The search OBJECT OF THE RESEARCH PROJECT was essentially done online. Criteria were defined which the tools had to meet in order to be consid- The research project was divided into the following ered. A considered tool ... steps: • Research of BIM processes and development 1. ... had to be available free of charge. of usage scenarios 2. ... did not have to be limited in time. • Search for free tools and derive software 3. ... could request a registration for use. classes • Definition of evaluation criteria 4. ... had to run on a current operating system. • Testing the tools and classifying them into us- age scenarios According to these criteria, about 80 tools could be • Prepare the results for the public on a website identified. They were assigned to 13 software classes 138 | eCAADe 35 - BIM - Volume 1 Figure 1 Usage scenario “Merge and Coordinate” with associated tools in a BPMN diagram. and written down together with a short description “Merge and Coordinate” in the wiki system. From this set, 19 tools were se- If several disciplines are involved in a construction lected and evaluated according to a criteria catalog. project, the disciplines usually work in their own spe- cialist models. By combining these models in a co- USAGE SCENARIO ordination model, it is possible to check the model To impart a usage scenario to the target group, we ex- at specific times and to perform collision checks. The plain each in three sections. The first section gives a collision check is only one method that is carried out more general overview and introduces the context. within regular reviews of the current planning stage. The second section explains an ideal scenario that In addition, semantic checks can also be carried out we believe should be implemented in a BIM process. using so-called model checkers. They serve to clarify The last section describes a possible scenario, which the completeness of the modeling or to check com- is supported by the tools found by us. One of the pliance with the customer information requirements. scenarios, the “Merge and Coordinate” scenario, is These activities fall within the scope of the so-called described below as an example in the manner de- BIM coordinator. Thus, coordination and modeling scribed above. The other scenarios are “Construction errors can be detected before the construction phase Schedule”, “Simulation and Computation”, “Presenta- and subsequent costs avoided. tion and Visualization”,“Release” and “Pricing”. The review of the coordination model can always be combined with a joint meeting. Nowadays, as dig- BIM - Volume 1 - eCAADe 35 | 139 ital communication channels are available in order to integrated in a central location. The model can now be able to make arrangements between the planning be tested for collisions or other technical aspects. For parties, even without a dedicated appointment, the the sake of simplicity, it is also possible to access the review should be carried out continuously. filtered views or selected sub-models from the coor- Ideal scenario. For this, it is necessary to use a com- dination model. mon data storage, on which regularly current ver- The result of the review is then communicated to sions of the specialist models are uploaded by the the responsible persons of the respective discipline, different disciplines. Anyone affected by a change to so that the latter can understand the comments and a model will be informed by email. In order to carry make the necessary adjustments quickly. out the review, the BIM coordinator takes advantage Supported scenario. For data maintenance, the of the coordination model, which has already been BIMserver offers the possibility to separately and cen- Figure 2 The overall process via tool interaction describes reasonable data exchange points. 140 | eCAADe 35 - BIM - Volume 1 trally provide IFC-based models by version. Once a can be downloaded after registration. The cata- new version of a model has been uploaded, the inter- log sorted by manufacturer has interesting search ested parties will be automatically notified by email.