Process factory extension

Aaro Kohonen

Engineering office Aaro Kohonen Oy was chosen as BIM coordinator for a process factory extension project in Helsinki, Finland. The owner-operator demanded models from all project participants from the beginning. After carefully comparing different design coordination tools Aaro Kohonen Oy gave Tekla BIMsight an opportunity to show what it's capable of.

Owner wanted to avoid clashes on-site – Aaro Kohonen delivers error-free design with Tekla BIMsight


The owner-operator of the factory extension wanted to improve the design and construction quality by moving from 2D to BIM. The shift to BIM lead to less clashes on-site and reduced project cost. The owner had good experiences with BIM design coordination in previous projects and therefore demanded 3D modeling for the extension and wanted to check for clashes in the design phase.

There was an architectural model for the old part of the factory but for the extension everything was modeled from scratch. Models were crucial because there are a lot of plant process and MEP components in a small space. Clashes could not have been avoided without BIM.

Modeling guidelines help BIM project execution

Aaro Kohonen is a part of FMC Group, a larger consortium of engineering offices. The group’s unified data modeling guideline helped to carry out the project. To start with, all participants agreed upon coordinates, way of working etc. according to the guideline. Agreeing these was really helpful for organizing the model workflow. Those who do not have access to such guideline can benefit from Tekla BIMsight design coordination guideline.

Design coordination workflow

All project participants agreed to use Tekla BIMsight and to deliver their models in Tekla BIMsight compatible formats. The plant process was modeled with Microstation, so DGN file format was used often in addition to IFC. MagiCAD was used for building services (MEP) and structural elements were modeled with Tekla Structures while the architect used Revit Architecture. Samu Ristolainen, BIM coordinator at Aaro Kohonen Oy, combined the models. The project team had design coordination meeting every 2 weeks. It set the pace for modeling: few days before the meeting all parties sent their new model to the project bank, giving Ristolainen two working days to combine them and check for clashes. Each combined model was archived.

Samu Ristolainen explains:

"I marked the most significant clashes with notes and made a tbp (Tekla BIM project)-file. In the meetings we reviewed the latest combination model from the project bank. During design and design coordination no drawings were used."

Design coordination meetings

In the meetings the project parties agreed how to handle the clashes and who needed to change one’s model. Total 10-15 persons attended the meetings: Each discipline had one representative, the owner by five and also a construction consultant was present. In the end, the owner-operator had the final decision-making power.

The project parties used Tekla BIMsight conflict checking functions a lot in additional meetings held for clash checking. Each model was cross-checked with every other model for clashes, and conflicts were saved in snapshots. The extensive use of clash statuses helped to mark all clashes that otherwise could have been be ignored in real construction.

There is also a clean room in the factory extension that sets some requirements. It was added to the plan later. A German company designs, delivers and builds the structures of the room. Some plans were in 3D PDFs and some in DWG. The new provider was introduced to Tekla BIMsight and they were provided with the project file so they can start to design their part.

User experiences

Samu Ristolainen, BIM coordinator at Aaro Kohonen gave some feedback about Tekla BIMsight: "Tekla BIMsight is easy to use and learn. Even designers without experience of 3D modelling learnt it quickly . Still there was enough features to go through the design coordination process. The owner was also very pleased. Especially the clip plane tool was found very helpful in communicating issues with others."

The project team used Tekla BIMsight versions from 1.2 to 1.5. The group sees new features, such as albums, slideshows and full-screen, very helpful for the future.

Tekla BIMsight is easy to use and learn. Even designers without experience of 3D modelling learnt it quickly. Still there was enough features to go through the design coordination process. 

Process factory renovation
Samu Ristolainen
BIM coordinator
Aaro Kohonen

Tekla BIMsight is easy to use and learn. Even designers without experience of 3D modelling learnt it quickly. Still there was enough features to go through the design coordination process. The owner was also very pleased.

Process factory renovation
Samu Ristolainen
BIM Coordinator
Aaro Kohonen