There is constant pressure to realize construction projects with ever shorter planning and construction times. In addition, construction should be even cheaper, with greater customization and even greater quality awareness. The Last Planner System (LPS®) and Takt Planning have become a common practice to deal with these challenges. Another approach to achieving this is Lean Construction Management (LCM®), which many owners and construction companies now rely on. Therefore this contribution aims to show an alternative approach for applying Lean in construction.
LCM® is the adaption of Kanban, a common approach of Lean Management – which originated in the manufacturing industry – to the construction process. Developed in 2008, over the past decades, this approach to process optimization has not only been used in the construction industry, but also been applied to numerous other sectors, such as shipbuilding, aircraft construction, civil engineering, and plant engineering.
The consistent process view and the implementation of the principle of a “pulling construction site” have a significant effect, especially on construction times. Time savings of between 20% and 40% (compared to the initial schedule) have been achieved in construction projects in Europe using LCM®. This process-optimized management results in a significantly smoother and thus trouble-free workflow. Another key element is daily quality assurance, which ensures “first-time-right” outcomes that cannot be achieved using conventional scheduling methods.
The LCM® approach has already triggered a revolution in numerous areas of the construction industry in many countries. The conventional construction site is still characterized by strong fragmentation of the design, construction and execution phases, with the individual trades working independently. Each trade optimizes its own process. While appearing to offer the best solution for the individual trade, the conventional approach often has a negative impact on overall project execution. Frequently, at the time scheduled for execution, the necessary material, approval, planning or experts are not on site, preventing smooth continuation of the process. Unnecessary delays result. In many cases, such issues are anticipated in the cost and schedule parameters of the project.
This is exactly where LCM® comes in for principals and construction companies with lookahead planning and the Kanban board system.
Lookahead planning is the essential communication tool in the interface between planning and execution, and also ensures systematic implementation of the planned process. Undertaken at the start of execution by all parties involved, lookahead planning focuses primarily on identifying critical process steps and any possible issues – and establishing a process flow. Milestones in lookahead planning describe stability criteria that must be achieved before the planned execution. Lookahead planning is updated monthly, and issue-free or stable progress is ensured for the next three to six months. Any issues identified are systematically tracked in an action list with an assigned issue owner.
In addition to lookahead planning, detailed planning with the Kanban card system is an essential tool for smoothing the construction processes. Detailed planning takes place on site and serves as a communication tool between the executing companies. It brings planning to where work is being done – on the construction site.
Its philosophy and culture are comparable to the LPS®. However, the methodology and implementation are more structured and more hands-on, and the board itself is more robust. The Kanban board is structured like lookahead planning on the basis of the project. So, similar to production planning in the manufacturing industry, it details the activities per day on the site for the next three to four weeks. This change in perspective to a product view clearly shows planned buffers, that is, days in which no work takes place in an area. This is where optimization comes in. Planning is undertaken on the site with the help of a simple tool – the Kanban board – with cards representing the days, areas and individual activities of the individual trades. This planning is undertaken weekly on site by the executing companies and site management, and is adjusted daily based on the progress and quality achieved. The integration of execution status and its clear visual representation make it easy for every worker to see what activities are planned. The planning, which otherwise only takes place in the site manager’s head, becomes transparent, allowing everyone to work on the common, optimized process and to identify any possible issues at an early stage. Any issues are visualized on the planning board three to four weeks before execution using Andon (problem) cards. This leaves sufficient lead time to address them. Such lead time is often missing if LCM® is not used, resulting in delays.
The result is a very resilient and smooth process with significantly reduced buffers and greatly accelerated execution. But the benefits are not only clear for the client. For executing companies, reliability of execution planning without major issues results in significant efficiency gains. Construction sites with no supplementary claims due to obstruction are not uncommon with LCM®.
LCM® can be used for all project types and for a wide range of project sizes. In Europe, the huge potential of the Lean approach has been used to optimize construction processes on projects ranging from small new school buildings to major museums and opera houses, as well as on power plant construction sites and office refurbishments. Its application is worthwhile for every project.