Delivering a quality construction project within the deadline and budget is increasingly rare. While limited resources and funding certainly play a role in unfavorable outcomes, waste and inefficiencies exacerbate the problem. As a result, many construction companies have adopted lean construction principles to reduce waste and increase value throughout the project lifecycle.

Among contractors using the lean methodology, 84% reported higher construction quality, 80% reported greater customer satisfaction, 77% reported increased construction productivity, and 77% reported improved safety.

Lean construction is certainly a buzzword in the industry, and many companies see the value of its implementation. However, it is not universally used, likely due to a lack of knowledge on the subject or adequate tools for implementation.

What is the Lean Method?

Lean construction is a project management method that focuses on minimizing waste and increasing the flow of value to achieve more successful results. The Lean methodology prioritizes customer demands and defines expectations based on stakeholder values. Furthermore, the lean construction process is replicable, making success a predictable outcome.

Unfortunately, construction projects often face limited resources, tight deadlines, and tight budgets. Lean construction provides a framework to maximize productivity and eliminate waste to overcome these constraints.

Evolution of Lean

The Lean methodology originates from manufacturing. After World War II, the automaker Toyota created a production system focused on waste reduction, improving the friendly atmosphere among employees, and increasing customer satisfaction. Other companies quickly adopted these advanced production strategies and began incorporating them into their sectors.

As lean methods made their way into the construction industry, the Lean Construction Institute was established in 1997. The group aims to develop and share information on how to improve construction project management through lean construction practices.

Principles of Lean Construction

Lean construction focuses on two core principles: eliminating waste and increasing value. These principles are applied in all phases of the construction lifecycle, from design to delivery, and by all stakeholders, whether the owner, architect, engineer, general contractor, subcontractor, or supplier.

Eliminating Waste

The Lean philosophy aims to eliminate not only physical waste but also waste of time and resources. Therefore, every construction activity is analyzed to remove any unnecessary steps. If waste cannot be entirely eliminated, it must be minimized as much as possible.

Construction activities that should be reviewed to eliminate waste include:

• Transportation: Simplifying the transport of materials and products to, from, and around the site.
• Excess Inventory: Storing only raw materials on-site that are needed in the near future to limit double handling. Practicing just-in-time inventory management: working with suppliers and subcontractors so that materials arrive when needed for installation and not before.
• Waiting: Limiting situations where a resource must wait for another before proceeding.
• Talent: Matching the talent and skills of the worker with the most appropriate activities to maximize productivity.
• Overprocessing: Eliminating unnecessary steps in workflows that do not add value.
• Overproduction: Not producing more than necessary or finishing a task before the next one can begin.
• Rework: Avoiding errors and quality defects in tasks that would require rework.

Increasing the Value of Your Construction Project

Every activity in lean construction is examined from the perspective of its value, specifically from the customer’s point of view. In the initial planning phase, understanding why a project is important or what the comprehensive benefits will be is discussed in a group. The established values shape expectations in all project phases.

Each activity must add value; a task is removed from the workflow if it does not offer value considering labor, equipment, and necessary materials. The ideal lean construction scenario is creating a “value stream” where all activities contribute to adding value to the customer.

In addition to eliminating waste and increasing value, lean construction also emphasizes continuous improvement, employee ownership, and stakeholder satisfaction as fundamental principles.

Benefits of Lean Construction in the Construction Industry

When implemented with the right tools and across the organization, lean construction is an effective management system that leads to better project outcomes. Common benefits of lean construction include:

• On-time project delivery: Thorough examination of each stage of the project plan allows teams to eliminate any inefficiency. Progress is closely monitored, and delays are communicated and mitigated. With lean thinking implemented, projects are more likely to be completed on time.
• Enhanced quality: Value-added activities focus on communication and collaboration. With all stakeholders, including contractors and subcontractors, effectively working together toward the same goal, conflict and rework are reduced. Installation quality is significantly improved, allowing for a more streamlined punch list and turnover process.
• Better cost control: Lean construction enables better cost control as inefficiencies are removed from all project activities. Additionally, the effort to reduce waste often translates into cost reduction.
• Safer site conditions: Each task is examined in a lean construction model with a focus on prioritizing safety. Any potential risks are identified and mitigated to ensure that work remains safe and productive. A safe workplace is a prerequisite for achieving lean construction.
• Increased stakeholder satisfaction: Improved results from lean construction methods boost stakeholder morale. Customers feel more confident in the longevity of their projects, approve of process transparency, and consider other projects in the same methodology. Similarly, employees feel more satisfied in their work and seek continuous improvement.
• Increased profitability: All the aforementioned benefits contribute to a better final outcome. Construction companies that carry out projects quickly and efficiently reap the rewards in the form of higher profits.

Methods to Achieve Lean Construction

Although lean construction is considered more of a philosophy than anything else, certain established methods can build the framework for a successful lean project. The following processes can help contribute to a successful lean construction project.

Line of Balance

The Line of Balance (LOB) is a way to measure project progress compared to the initial plan. In most cases, the comparison is graphical and shown with a diagram. Project metrics, such as cost or the percentage of work completed, are placed on the y-axis and compared to the project schedule on the x-axis. The LOB can be used to visualize current progress versus expected progress so that resource modifications can be made to stay on the right track. Additionally, LOB diagrams display a production rate that can be used to forecast future performance.

Inverted Planning and Scheduling

Traditional scheduling of construction projects is linear, with each activity placed in sequential order. Unfortunately, it often lacks details and ignores critical tasks that are far in the future. Inverted planning is the type of project schedule used in lean construction. With this scheduling method, planning starts at the end of the project and works backward to ensure that each detail is properly considered.

Inverted planning is highly collaborative: an experienced construction leader will gather representatives from each subcontracted company to define their progress expectations and discuss activities that depend on other businesses. Sessions often use color-coded sticky notes placed on a wall in a common area, with each note representing an activity. It exposes all requirements and constraints so that the team can work together to optimize resources and achieve desired outcomes.

The Last Planner System (LPS)

The success of inverted planning depends on the implementation of the Last Planner System (LPS) workflow method. Developed by the Lean Construction Institute, the LPS emphasizes group planning to hold each contractor and subcontractor accountable for the promised outcome. During a collaborative exercise, business representatives set their production expectations and work on any obstacles that may hinder progress. The individual or trade that must complete their work before the next phase of work can begin is called the Last Planner. The title holds that individual, as well as all parties involved in the planning session, accountable for their progress.

Conclusion: On-time Project Completion, Every Time

With the right tools and techniques, the implementation of lean construction methodology allows for successful project outcomes and satisfied clients and employees.