Lean and BIM Synergy in Practice

21 Sept 2016

Recent research on BIM and Lean Construction (LC) shows that there is a significant synergy between the two. The many positive interactions includes: reduction in process variation and cycle-times, increased visualisation of products and processes, automation of some non-value adding activities, increased collaborative working, advanced prefabrication options, and better value capturing and rapid generation of alternatives through the use of BIM come to fore¹. All those points also constitute some of the important mantras of LC. It should also be noted that the BIM-Lean synergy is not limited to the design phase and extends over the construction life-cycle with the rapid advent of multidimensional BIM capabilities (nD BIM)².

The design phase in the construction life-cycle is an area where this synergy is most apparent. The LC related design priorities and concepts such as Target Value Design, Set Based Design, client defined value, collaborative design etc. extensively leverage the BIM capabilities of multi-trade coordination and rapid production of design alternatives with fewer errors. The leveraged BIM capabilities also include better visualisation of the design intent, efficient modelling for constructability, powerful simulation options (e.g. lighting, heating, earthquake resistance - see Figure 1) and advanced pre-constructıon analyses (e.g. virtual site planning and logistics, integration of BIM models with schedules and costs or 4D BIM and 5D BIM respectively)^{3, 4}.

Figure 1. Design simulation using BIM for better value

The use of BIM to support LC goals has been widening in the construction phase. The increasing integration of multidimensional BIM with existing information systems (i.e. Enterprise Recourse Planning) and emerging technologies such as Virtual Reality, rapid laser scanning and point cloud generation adds to the possibilities.

Currently, BIM supports visualisation in the Last Planner meetings (see Figure 2), design briefs and stakeholder engagement. There are also efforts to create state-of-the-art BIM based systems to visualise construction flows and to facilitate on-site visual controls (See Figure 3). The 4D and 5D capabilities of BIM provide constructors with a better understanding of different alternatives and cost/schedule control. 4D/5D simulations for resources, time, safety, constructability etc. have been used with the outcomes of reduced cycle times, reduced Request for Information (RFIs), reduced wastes and increased safety in some work tasks.

Figure 2. BIM support in the Last Planner meetings

Clash identification at the construction stage is also prevalent. BIM models can also support Just-in-Time (JIT) based information, project drawing, material/logistics flows and advanced, model-driven prefabrication thanks to their high compatibility with industrial Computer Numerical Control (CNC) units. The combined use of BIM models, BIM servers and emerging technologies enable the automation of some non-value adding activities such as site production monitoring, sub-contractor progress payment calculations, production quality control and tolerance checks, checking production against construction codes/requirements. The machine readable nature of BIM models gives way to integrate construction site models with additional logic layers like automatic site-safety layout checks (e.g. automatic checking if site trailers are dangerously close to chemical storage areas), which could be also viewed as a warning poka-yoke (mistake proofing) for construction safety.

Figure 3. KanBIM - an on-site prototype for the integration of the kanban and andon functions with BIM models

Although initial design has an effect on every phase in the construction life-cycle, the total cost of a project is comprised largely of facilities and operations management (FM/OM) costs. Thus, efficiency gains in the maintenance/operations phase will have relatively larger impacts on the overall construction life-cycle (see Figure 4). Current BIM and Lean discussions revolve mainly around the design and construction phases. A more balanced research/practice approach with more emphasis on FM/OM can be expected in the near future. One interesting and challenging area is the use of BIM/Lean in existing assets within refurbishment, retrofitting and demolition efforts. The integration of emerging technologies with BIM models presents a wide variety of possibilities in the FM/OM phase as well⁷. Also, the fast advent of Big Data may have a fundamental impact on Lean, BIM and FM/OM practices in the near future.

BIM and Lean match well with many FM/OM activities, including: controlling life-cycle cost and environmental data, effectively locating building components and material inventory, asset tracking, facilitating retrieval of real-time integrated building, monitoring energy and facilities use etc. The traditional handover practices from the construction phase to the FM/OM phase should be analysed and redesigned with a Lean/BIM perspective.

Figure 4. Changing meaning of BIM through the construction life-cycle

Presently, there are also many challenges before the Lean/BIM synergy, and their common dissemination and diffusion in the construction industry. Some of those challenges are technology related such as the diversity of BIM tools and interoperability issues, problems in the integration with other IT systems, the current fragmentation and competition among BIM software vendors and the lack of BIM libraries and established world-wide standards (still).

Other issues are mostly management and industry culture related including: unclear roles and responsibilities, lack of effective collaboration between project stakeholders, inherent problems within the prevalent project delivery systems, cultural barriers towards adopting technologies and mindsets, organisational resistance, the lack of a sufficient legal framework, the lack of an educated workforce, and the relatively low awareness of both of the concepts in the industry (still).