BIM and Lean Construction are promising methods for improving the construction process, with BIM focusing on the product and Lean Construction on the process. Combining both methods can lead to further improvements. This article presents an analogue simulation game that links Lean Construction and BIM through QR codes, with a case study to demonstrate feasibility and value.

State of the Art

In the execution phase, permanent monitoring and control of the construction processes takes place within the framework of Takt Control. The basis for this is the constant monitoring, processing, availability and visualization of information about the current status of the construction site. As a central control tool, Takt Control Boards are used for each Takt section in a construction project that is planned according to the Takt principle. Takt, floor plans, construction time schedules, etc. are displayed on them.

When working with analogue Takt Control Boards, newly acquired information is initially only recorded daily and locally on the construction site. In order to transfer this information into a digital system, such as digital construction models, digital schedules or digital construction diaries, it must be digitalised afterwards. In addition, a major challenge is the spatial separation of the monitoring of data and its users. The collection of data gained through the Takt Control Boards would theoretically enable detailed reporting. However, construction companies are often involved in several widely distributed construction projects. It is therefore not sufficient to present information on the progress of the construction site exclusively in analogue form on site.

Lean Construction Simulation Game

The hotel model is a simulation game that teaches the principles of Takt Time Planning and Takt Control to specialists, managers, and process managers in construction-related sectors. The game consists of three stages, with each stage having a debriefing period where participants reflect on the construction process to identify opportunities for improvement. Participants take on different roles, such as a client, construction manager, building inspector, and trade partners. The aim is to finish the hotel within 22 minutes. The first stage has no introduction to Takt Time Planning and Takt Control, leading to an unstructured, uncommunicative, and inefficient way of building. In the second stage, participants are taught the eight steps of Takt Time Planning, leading to better construction progress. In the last stage, participants learn Takt Control and conduct regular on-site meetings. Through this simulation game, participants can learn lean principles and soft skills such as team building and communication.

Implementation of the Digital Monitoring

The simulation game has already been played with hundreds of participants within two-day Lean Construction workshops. From these previous workshops, the question about the digitisation of the Takt Time Planning and Takt Control came up repeatedly. This makes it clear that there is a need for a digital link from the participants' point of view.

The digital monitoring system for the Takt Time Planning and construction process involves the use of QR codes, smartphones, and a BIM model to track the completion status of each trade's work. Each room in the BIM model is equipped with attributes indicating the Takt it belongs to and the trades that have passed through it. QR codes are assigned to each Takt and trade to enable easy completion tracking. When a trade completes work in a Takt area, they scan the QR code with their smartphone, which takes them to a form where they can enter the completion. This information is then transferred directly to the BIM model, which displays the degree of completion using color schemes. The visual representation of the stage of completion in the digital model increases the quality of meetings and allows for a binding statement about the production status of each trade to be made in advance. The system has potential for further integration with other processes, such as tracking individual components and noting the quality of work carried out.

Results

After testing the developed simulation game, it became clear that linking the analogue and digital models demonstrated the benefits of using the BIM method for Takt Time Planning and Takt Control. The BIM's core, an up-to-date and accessible information model, provided added value not only to regular meetings but also to the client who could easily track completed parts of the building.

Moreover, the process automation potential, such as key figures creation, was also acknowledged. Considering the ultimate goal of training for larger construction sites, it made sense to teach participants how to link buildings with BIM models. This could inspire participants to come up with their own implementation ideas for their respective projects. The developed simulation game is not limited by the use of Takt Control. It is also possible to use the BIM model to improve the Takt Time Planning, e.g. to automate the determination of the Takt areas. A workshop also offers suitable framework conditions for testing such concepts in a playful way. This approach could be explored in future work.