Frequently asked questions

BII GmbH (Building Information Innovator GmbH) is a German software company for digital construction processes. BII was founded in 2018 as a spin-off of the University of Würzburg and Biberach University of Applied Sciences and today employs more than 40 people at its Würzburg and Biberach an der Riß locations. The interdisciplinary team of software developers, civil engineers, designers and modelers makes construction projects more predictable, more efficient and less error-prone.

BII GmbH offers four services: the dProB simulation software for 4D construction process simulation, process engineering as a hands-on consulting service, individually developed construction management solutions for site coordination, and simbox, an AI software for construction process planning. You run dProB in-house yourself; with process engineering the process engineers at BII GmbH carry out the simulation for you.

BII GmbH works for owners and builders, planning and engineering firms and construction companies in building construction, civil engineering, infrastructure and rail. Typical projects involve many stakeholders, tight schedules, short track possessions or complex site logistics — from inner-city building sites with a confined footprint to major tunnel projects.

BII GmbH has two locations in Germany: Würzburg (Leightonstraße 2, 97074 Würzburg) as the developer hub and Biberach an der Riß (Königsbergallee 3, 88400 Biberach) as the process engineering location. BII GmbH supports projects throughout the German-speaking region as well as international construction projects; project support is available in German and English.

BII GmbH has supported more than 250 construction projects with a combined project volume of around 12 billion euros, typically identifying five to ten conflicts per project. A development partnership with the Rhomberg Sersa Rail Group has been in place since 2019. BII GmbH has been a framework contract partner of Deutsche Bahn since 2023 — the framework contract was renewed in 2026.

dProB is an input-based simulation software by BII GmbH that runs the construction process through as a 4D simulation before anyone builds anything. dProB links your imported BIM model with schedules, resources and the output rates of your equipment, and makes spatial and temporal dependencies visible in the model. That way you spot conflicts and bottlenecks yourself before they get expensive on site. dProB is a Windows desktop application and runs locally on your machine.

A 4D simulation links the three-dimensional building model with the fourth dimension, time. In dProB you import your BIM model, assign activities, equipment, resources and dependencies to the components and play the construction process back at any point — fast-forward and rewind like an interactive video. A Gantt-style view places the activities on the timeline, and resource totals appear in dashboards. All results are based on your own inputs.

No. dProB does not replace CAD, BIM or scheduling software, it complements them. dProB is explicitly not a modeling tool: imported IFC and FBX models are visualized and can only be edited to a limited degree. Nor does dProB replace conventional schedules. You import BIM data, use it to validate planning assumptions and construction processes, and feed the results back into your digital workflow — your planning stays where it is.

dProB suits building construction, civil engineering and infrastructure projects — from residential buildings, office complexes and industrial halls through foundations and complex civil works to roads, bridges, utility networks and rail projects. The benefit is greatest where schedules, site logistics or track possessions are critical and several trades have to be closely coordinated.

The earlier simulation enters the project, the greater its value. dProB is particularly useful during the early design stages — basic evaluation, preliminary and concept design — as well as during detailed design, because changes are still cheap there. It is also worthwhile during tender preparation and construction; at that point the focus shifts to safeguarding decisions already taken.

dProB is available in German and English. Support from the BII GmbH team is available in both languages too, so international project teams can work with the same software and the same point of contact.

simbox is an AI software by BII GmbH for construction process planning. simbox combines domain-specific AI agents with discrete-event process simulation and construction expertise, and validates construction processes on a data basis before the first machine arrives. The AI agents are trained on more than five years of simulation data, spot risks early and develop optimized execution variants.

dProB is the simulation software available today, with which you model and run construction processes yourself. simbox builds on it and automates parts of that work: AI agents reduce the complexity of building a simulation, assess dependencies and propose optimized variants. dProB is in productive use at customers; simbox is under development at technology readiness level TRL 6–7.

The first productive use of simbox in customer projects is planned for September 2026. Until then BII GmbH is validating simbox internally on real projects run by its in-house service unit. Anyone who would like to join the early access program can be put on the list by BII GmbH on request — simply get in touch via the contact form. If you would rather not wait, you can simulate construction processes with dProB today.

Process engineering is the consulting service of BII GmbH: the process engineers translate the schedules, resources and constraints of your project into a robust digital model, run the construction processes through and make bottlenecks visible before they arise on site. You need neither your own software nor to build up in-house expertise — a dedicated contact accompanies your project from the first conversation to the result.

In four steps. In the first conversation you describe the project, the idea and the challenge. You then hand over the data you have and we define the objective together. Next we build your construction process in the model and run scenarios. Finally you receive robust analyses and clear recommendations — plus, on request, a video of the detailed construction process.

Only three things are essential: a real construction project, a rough idea of the intended construction process, and the specific challenge you want to safeguard. Helpful but not required are existing plans (PDF, Excel, MS Project), 3D data (IFC, FBX, STEP) as well as site survey data and point clouds. BII GmbH works with data in almost any format — we work out the rest together.

A process engineering project typically takes four to twelve weeks, depending on the size of the project and the number of processes examined. From the first conversation through data handover and modeling to a robust recommendation, we go through four steps. We respond to your inquiry within one working day.

No, there is no minimum project size. What matters is not size but complexity: the more trades, dependencies, schedule constraints or logistical bottlenecks a project has, the greater the benefit of simulation. Mid-sized projects with a high coordination effort benefit clearly too.

Yes, as a complement rather than a replacement. Takt planning and lean construction are strong on the organizational side: they create process stability, reliable coordination and team focus. The underlying planning information is largely held in an abstracted, activity- and time-based form. As project complexity grows, that representation reaches its limits, because it can only partly capture how construction processes, resources, logistics and building states actually interlock. Simulation supplies exactly that layer: it checks whether a takt holds up under real constraints before it becomes binding. In practice the two reinforce each other — the organizational strength of lean and the computational rigour of the model.

Modeling effort rises with the level of detail, so it is weighed against the expected benefit. For short, small-scale projects with few trades, no schedule constraints and no logistical bottlenecks that effort is often out of proportion — a coarse view at milestone level will usually do, and going down to equipment level would be money wasted. The benefit becomes clear where complexity is high, the project runs long, there are many interfaces and logistical constraints are tight. What makes sense for your project is something we discuss openly in the first conversation — including when the honest answer is that the effort would not pay off.

BII GmbH bills process engineering services at hourly or daily rates. The rate depends on the complexity of your project and the number of processes examined — there is no off-the-shelf fixed price, you pay only for the actual effort your project requires. You receive an individual quote after a short initial conversation.

Construction management at BII GmbH is an individually developed software solution for the transparent construction site — not off-the-shelf software. It brings the relevant interfaces of a construction project together in one place: existing planning data, sensors and the operating systems on site. The result is a digital platform on which schedules, logistics and resources stay continuously visible to everyone involved.

Four building blocks, combined to fit each project. Planning & coordination synchronises construction activities, schedules and working zones in real time. Logistics management coordinates site logistics, vehicle movements and access routes. Live safety & tracking locates personnel and equipment in real time. The individual system integration ties in the interfaces of your project — it is the core of every solution.

Rollout typically takes three to six months, depending on which modules are used. The process has four steps: an on-site meeting with a requirements analysis, design and integration of the relevant interfaces, rollout including training for everyone involved, and then ongoing operation with continuous development as the project progresses.

Both are possible — and can be mixed module by module. You can have the platform hosted by BII GmbH or run it on your own infrastructure. At the Semmering Base Tunnel both variants are in use, depending on the module. Which split makes sense for your project is something we clarify during the on-site requirements analysis.

No. Maximum data depth is not required for a working target/actual comparison — highly granular machine data is often less useful than a consistent, decision-oriented level of information. What matters is that the data captured fits the decisions that actually have to be made. We therefore start with the data sources your project already has and extend only where a specific decision calls for it. Waiting for a complete sensor infrastructure costs more time than it adds in accuracy.

The solution is proven on major European infrastructure projects. At the Koralm Tunnel — at 32.9 kilometers the longest railway tunnel in Austria — a digital platform by BII GmbH coordinated a construction volume of around 270 million euros; after its introduction there were no further schedule delays, and the site remained fully manageable from the home office. At the Semmering Base Tunnel (27.3 km) construction is currently under way.

dProB imports geometry via IFC and FBX, track alignments via DXF and LandXML, and images in PNG and JPG format. There is also a self-scriptable XML workflow for individual data handovers. Export from dProB is in CSV format.

dProB fits into your BIM workflow as a complementary tool. You import conventional BIM data into dProB, carry out targeted analyses and validations there, and then feed the results back into your digital workflow or your BIM system. dProB serves to validate and optimize planning and execution processes, not to create models.

No. A BIM model is the most convenient route, but not a prerequisite. What counts for simulation is the geometry, not the level of attribution: a simplified spatial representation matching the level of detail of production planning is often enough. Where no model exists at all, BII GmbH builds one from the available documents — including PDFs, point clouds or as-built records. That is the norm for refurbishment work and older infrastructure projects, where a usable BIM model is rarely available.

No. dProB takes on your existing BIM or IFC model — there is no need to model anything twice. On that basis, activities, resources, dependencies and takt are linked to the model. Where project-specific components are missing, BII GmbH models them quickly as needed, without long lead times.

Yes. Plans can be exported from dProB in CSV format and used elsewhere. dProB stores your plans and templates locally on your machine; they stay there even once a license ends. Those files can only be opened and edited meaningfully with dProB, however.

Pricing for dProB depends on the license model, the number of users and the scope, and is quoted individually on request. Tell us briefly about your project — via the contact form, by email to contact@bii-gmbh.com or by phone on +49 151 11659235. We get back to you within one working day and go through the details and the process with you.

Three license packages. Personal for individuals and small companies, with one user, access to dProB, dProB Hub and dProB Viewer plus 50 GB of viewer storage. Team for small and medium-sized companies, with an unlimited number of users within the licenses and accounts ordered, collaboration in the viewer, dProB Cloud and 250 GB of storage. Enterprise for medium-sized and large companies, with an unlimited number of users plus storage, support and additional services by individual agreement.

Through an inquiry to BII GmbH — there is no self-service purchase. Get in touch via the contact form, by email to contact@bii-gmbh.com or by phone on +49 151 11659235. Sales get back to you within one working day, work out the right license model with you and handle the rest of the process.

Both are possible. The standard license is a named-user license: it applies to exactly one user, who may install dProB on any number of devices but can only be signed in on one device at a time. The floating license can be assigned to several users; one device works with it at a time, and the assignment switches automatically after about five minutes of inactivity. Which model is more economical depends on how regularly your team works with dProB.

BII GmbH accepts payment by invoice, SEPA direct debit and credit card. Billing is monthly in advance; the first invoice falls due immediately after the contract is concluded. All prices are net and exclude statutory VAT. Which payment option suits you — invoicing for public owners, for example — is something we settle together during onboarding.

Yes, dProB can be canceled monthly. The software rental contract runs for one month and renews automatically by a further month unless notice is given at least three days before the end of the term. Notice must be given in text form. Access to dProB ends when the contract ends; the contract terms you conclude with BII GmbH are what applies.

Yes. A trial and demo access is available for dProB. Request it via the contact form, by email to contact@bii-gmbh.com or by phone on +49 151 11659235. As a rule we first show dProB in a personal demo using a construction process close to your own, so you can judge the benefit for your own construction process.

Yes. dProB is free for students and lecturers. You register at license.bii-gmbh.com and submit proof of your current university enrolment; activation follows within 48 hours. For lectures and larger student projects, BII GmbH additionally provides lecturers with group licenses and teaching material — on request via contact@bii-gmbh.com.

Plans and templates stored locally stay on your machine, though they can only be opened meaningfully with dProB. Data you have placed in dProB Cloud or the dProB Viewer can be downloaded for a further three months after the contract ends, via a separate export mechanism; after that BII GmbH is entitled to delete it. So export anything you want to keep using independently in good time.

The minimum requirement for dProB is Windows 11 with an Intel Core i5-12600, AMD Ryzen 5600 or comparable, 32 GB RAM, an NVIDIA GeForce RTX 3060, AMD RX 6600-XT or comparable, and 10 GB of free disk space. Recommended are an Intel Core i7-13700 or AMD Ryzen 7700, 64 GB RAM and an NVIDIA GeForce RTX 4060 or AMD RX 7600-XT. The more detailed the planning and simulation, the more powerful the hardware should be. BII GmbH publishes the current version of these requirements in the user forum.

dProB runs on Windows PCs and requires Windows 11. There are no versions for macOS or Linux. The dProB Viewer, by contrast, is platform-independent: it runs in any HTML5-capable browser and therefore on tablets too, regardless of the operating system.

The dProB Viewer is the browser-based view onto projects previously exported from dProB and uploaded. Several users can view, play back and comment on project versions at the same time without installing dProB themselves. It requires an HTML5-capable browser and at least 16 GB of RAM — device and operating system are irrelevant, and the viewer also runs on tablets directly on site.

dProB consists of four components: the dProB Windows desktop application for modeling and simulation, dProB Hub for managing installations, versions and local projects, the browser-based dProB Viewer for viewing and commenting on exported projects, and dProB Cloud as shared storage for project files, templates and equipment libraries. Which components are included depends on the license package booked.

That depends on the license type. With a standard license (named user) your device stays assigned for around three hours after login — during that time you can use dProB offline. After that you have to sign in again. With a floating license offline use is not possible, because the device assignment expires about five minutes after the last activity. Independently of that, the portal login has to be repeated roughly every four weeks.

The easiest route is a short demo: you describe your project, we show you dProB on a construction process close to your own. Get in touch via the contact form, by email to contact@bii-gmbh.com or by phone on +49 151 11659235 — we respond within one working day. Whether the software or the consulting service is the better fit is something we work out together.

Yes. BII GmbH offers one-day training courses on dProB and its components, online or on site. The content can be chosen from the standard training catalog or tailored entirely to your team and your projects. Training can be booked independently of the license package; prices, minimum durations and surcharges for on-site dates outside the German-speaking region depend on the individual quote.

Documentation and manuals are available in the BII GmbH user forum at forum.bii-gmbh.com. It also has a quickstart section for getting up to speed quickly and a place to exchange notes with other users. In addition, a video series on the BII GmbH YouTube channel walks through the software step by step using examples.

Existing customers reach product support on a ticket basis by email at support@bii-gmbh.com — included in all license packages, with service hours Monday to Friday from 9 am to 5 pm. For everything else, such as demos, quotes, licenses or project consulting, use contact@bii-gmbh.com, the contact form or the phone number +49 151 11659235. Many technical questions are also already answered in the user forum at forum.bii-gmbh.com.

We respond to sales and project inquiries via the contact form, email or phone within one working day. Under standard support, which is included in all license packages, BII GmbH answers tickets within three working days as a rule. Service hours are Monday to Friday from 9 am to 5 pm, except for the period from 20 December to 6 January. Premium support with a shorter response time can be booked in addition.

Yes. Within what is economically reasonable, BII GmbH aims for an availability rate of 99.5 per cent per calendar year for the platform. Four levels apply to incidents: for a major disruption of core functions (level 1) troubleshooting starts no later than four hours after the report is received, for level 2 on the second working day, and for level 3 no later than the fifth working day. Scheduled system maintenance does not count as downtime.

BII GmbH releases updates for dProB regularly. They contain new features as well as improvements and bug fixes, so you always work with the current version. Updates are included in all license packages; to install them dProB needs an internet connection at regular intervals.

dProB is designed as a locally installed (on-premise) application: project data stays on your machine and is not transferred to the internet automatically. Only the portal login runs online. Data only reaches BII GmbH servers once you deliberately upload projects to the dProB Viewer or dProB Cloud. Where personal data is processed, we conclude a data processing agreement under Art. 28 GDPR as required.

No. simbox is not trained on customer project data, but on the experience and learnings from the simulation projects BII GmbH has carried out itself with dProB — that is, on process knowledge, not on third-party project content. Your models, schedules and cost bases remain your data.

The BII GmbH servers are located in Germany. Data is backed up regularly; the server provider meets high standards for security, availability and data protection.

Yes. On request BII GmbH offers private hosting and individual deployment scenarios, complemented by SSO integration and custom branding. For construction management solutions, operation on your own infrastructure is just as possible as hosting by BII GmbH — and the two can be mixed module by module. Scope and terms are set out in a separate quote.