The Principles of Lean Construction: Enhancing Productivity and Quality
The construction sector faces many challenges, ranging from supply chain disruptions to labor shortages and environmental concerns. Many tools and frameworks promise to help construction managers and construction project managers address and overcome these issues, but few are as widely known or respected as lean construction.
With origins in lean manufacturing but now reflecting the unique realities of the construction industry, lean methodologies reveal how construction managers can maximize value and minimize waste. We will discuss these opportunities in detail below, revealing how aspiring construction managers and project managers can make the most of the lean ethos.
What Is Lean Construction?
Understanding lean construction begins with recognizing the widespread influence of the ‘lean’ concept across numerous sectors and in our modern economy at large. Lean brings a systematic approach to reducing waste while emphasizing value creation and collaboration.
The Environmental Protection Agency (EPA) describes this business model as being centered around “eliminating non-value-added activities (waste) while delivering quality products on time at least cost with greater efficiency,” adding that lean strategies can lead to “rapid, continual improvement in cost, quality, service, and delivery.” Lean construction is a project delivery system that reveals how core lean principles play out in construction management.
History of Lean Construction
Although lean construction’s origins as a formalized practice centered around the manufacturing industry, many lean principles existed before lean was formally adopted as a construction strategy, as explained below:
Early Influences
Many principles currently associated with lean manufacturing (and, by extension, lean construction) emerged long before this framework was formalized. Henry Ford, for example, was hugely influential, revealing the power of continuous flow and standardization within the manufacturing sector and setting the stage for the lean principles to follow.
During this time, many significant construction projects also incorporated elements of what would later be described as lean thinking. For instance, the engineering marvel known as the Empire State Building, involved optimized workflows and even railway-based materials deliveries that reflected the ethos of just-in-time. These strategies allowed the 102-story building to be constructed in just over one year.
Formalization of Lean Construction
Focused on eliminating waste, the Toyota Production System represented one of the earliest and most significant contributions to the lean ecosystem. It revealed how concepts such as Just-in-Time (JIT) production could help businesses eliminate waste.
Following Toyota’s internal successes adopting lean practices, this concept took over in the West during the 1980s. A joint Toyota-GM effort known as NUMMI helped demonstrate lean’s value in the U.S. Lean principles found a broader audience with the publication of The Machine That Changed the World in 1990.
Soon after, lean made the leap to construction. Lauri Koskela published the influential paper Lean Production in Construction, arguing that concerns typically associated with the “conventional production view” were just as relevant in construction, especially waste, defined as “non-value-adding activities.”
Growth and Global Adoption
In the late ‘90s, Glenn Ballard and Greg Howell co-founded the Lean Construction Institute (LCI) and developed the Last Planner® System (LPS), which we will discuss in more detail below. This prompted a noteworthy shift away from traditional command-and-control processes, bringing a more collaborative approach that was adopted on a global scale during the 2000s.
Core Principles of Lean Construction
Lean construction shares core principles with lean manufacturing, including an emphasis on the production of value — the conversion of resources (such as time or labor) into positive outcomes that exceed stakeholder expectations. Other fundamental principles include continuous improvement and respect for people. These principles may play out differently from one project to the next, but if consistently applied, they can lead to significant improvements in productivity and quality.
1. Identify and Define Value From the Customer’s Perspective
Value identification involves developing an in-depth understanding of clients’ needs or preferences, going beyond functional building requirements to encompass desired cost, timing, and quality outcomes. Deep engagement with clients or stakeholders can reveal what “value” means to various parties, with these insights forming the basis for future planning and coordination.
2. Map the Value Stream
Value streams highlight the sequences of activities used to deliver products or services, extending from project inception through handover. Value stream mapping (VSM) offers a visual and collaborative method for process analysis. Teams utilizing VSM map out all required steps and subsequently evaluate each step. This evaluation determines if a step adds value or is non-value-added, based on the definitions of “value” identified earlier in the process.
3. Create Continuous Workflow
LPS promotes streamlined workflows by fostering continuous coordination through collaborative planning, including the effort to identify and address concerns known as constraints, which prevent work from continuing as planned. Constraint identification and analysis may occur during lookahead planning, with “ready work” (free of constraints) prioritized for weekly work plans. This proactive approach improves reliability and can lead to smoother handoffs.
4. Establish Pull Planning and Scheduling
Pull planning focuses on beginning with the end in mind, eventually working backward to reveal what makes it possible to reach a given goal or objective. LCI guidance suggests that this technique can establish “what should be done,” adding that it allows teams to determine the “key handoffs of work or information needed to deliver a milestone.” This addresses one of the most significant pain points where waste is otherwise likely to occur.
5. Pursue Perfection Through Continuous Improvement
Continuous improvement represents one of LCI’s core tenets, capable of “foster[ing] an environment where innovation can occur.” LCI resources explain that “maintaining a mindset of continuous improvement is paramount for…overall success.”
This may involve pinpointing concerns that underscore variance, as these insights can help teams produce more consistent workflows. Variances prevent teams from performing tasks as planned and could be sparked by anything from lack of information to changing conditions underscoring stakeholder satisfaction.
Understanding the root causes of these variances (especially those that most frequently stand in the way of predictable work) can limit the likelihood of these issues continuously impeding progress. Also essential: checking tasks planned against tasks performed as planned. This confirms alignment between execution and expectations, also revealing where further adjustments may be required.
Key Concepts and Tools Used in Lean Construction
Many frameworks guide lean construction, allowing construction managers and construction project managers to apply lean principles in a practical and approachable manner, all while pursuing waste reduction and continuous improvement through careful coordination and extensive collaboration. Top techniques include:
Last Planner® System (LPS)
The Last Planner® System brings a holistic approach to lean construction. Developed by Glenn Ballard and Greg Howell, this lean method focuses on those who adopt the most hands-on functions in the construction process — the “last planners.” LCI defines “last planners” as those who are sufficiently close to the work but also hold the “authority to make decisions regarding the schedule and to make reliable commitments to complete the work of their discipline.” They may be trade foremen or design discipline leads, although, with smaller jobs, superintendents may cover this role.
The LPS framework suggests that planning should occur in greater detail when it is nearly time to “do the work” and that those who truly understand the day-to-day realities of the worksite lead the charge when designing work sequences and drafting the concept of operations. These last planners come together to create production plans that align with key milestones. This process is facilitated by the general contractor superintendent. This collaborative effort underscores the lean principles of Respect for People, fostering, as LCI explains, “mutual respect among all people involved in an affected by a project.”
Target Value Design (TVD)
Meant to reduce project cost without compromising quality (or scheduling), Target Value Design (TVD) represents a comprehensive and highly disciplined management approach applied throughout each project to ensure the fulfillment of operational needs and values. This engages all project team members early in the design process, forming a clear contrast to conventional, large-batch approaches. Meanwhile, cost becomes an input (rather than an output) to the design.
TVD relies on a systematic series of steps:
1. Defining owner value.
2. Defining the project and condition of satisfaction.
3. Steering design to targets.
4. Steering construction to targets.
Integrated Project Delivery (IPD)
Designed to bring about improved communication and collaboration between the numerous parties involved in construction projects, the Integrated Project Delivery (IPD) framework sharply contrasts conventional design-bid-build models.
While previous project delivery efforts separate contracts involving project owners and various designers, builders, or suppliers, IPD aligns the interests of these diverse stakeholders, emphasizing joint decision-making across all project phases. Meanwhile, a shared risk and reward structure enables cost and benefits to move across traditional boundaries to promote the best possible project investments.
5S Workplace Organization
Originating from Japanese manufacturing strategies, the 5S method is heavily utilized in the supply chain sector but is also relevant to lean construction. It encompasses these key concepts:
- Sort. Assess and eliminate tools or materials not needed to prevent workplace hazards. This may also encompass information, removing unnecessary details to limit confusion while ensuring informed decision-making.
- Set in Order. This phase involves organizing all that remains (information, materials, or equipment) after sorting. This ensures not only that everything has a proper place, but also that everything aligns with preferred workflows.
- Shine. This S demonstrates the value of ongoing improvements by encouraging team members to take pride in their work. This may involve cleanup protocols, although experts at LCI add that this ethos can also be applied to optimizing the use of information, perhaps by using “file-naming structures to easily see where the latest file is.”
- Standardize. Highlighting the value of consistency, this step demonstrates how repeated processes can boost efficiency over time. This could involve clear and easy-to-follow procedures that maintain organization across construction work sites.
- Sustain. Providing the chance to transform 5S achievements into long-term habits, this phase may involve briefings or other strategies that improve accountability while encouraging team members to take ownership of their work.
Benefits of Lean Construction
Implemented strategically, lean construction can usher in many major benefits, including:
- Delivering value. Lean construction centers around one core priority: the delivering of value to both the owner and stakeholders. This forms the basis for all other collaborative efforts and decision-making processes.
- Faster Project Delivery. Flow optimization helps to limit interruptions or bottlenecks that commonly delay construction projects, leading to shorter overall project durations and greater scheduling reliability. With non-value-adding activities out of the picture, teams can limit wait times and rework, thereby significantly picking up the pace.
- Higher Quality Outcomes. With quality embedded in all steps, lean limits variance in construction while making the most of clearly defined standards and protocols. Inspections take on a reduced level of importance. Instead of depending on these to catch errors after they’ve been made, lean strategies draw on collaboration and planning to avoid these mistakes in the first place.
- Lower Costs. Reduced waste, expedited workflows, and other lean advantages coalesce to produce significant cost savings. Although, as LCI points out, lean strategies are not exclusively about cutting costs (instead shifting the focus to driving value), this key benefit can be attained by limiting storage expenses, preventing damage, and enhancing resource allocation.
- Reduced Waste. Core lean principles emphasize waste reduction, so it should come as no surprise that this is one of the most significant advantages of applying this framework to the construction industry. By limiting idle time and avoiding rework, lean construction can lead to significant waste reductions involving not only materials, but also time and effort.
- Improved Safety. Promising case studies suggest that lean strategies can improve workplace safety by reducing high-risk labor hours and limiting the pressure to rush through potentially dangerous tasks. Additionally, lean advocates for a greater understanding of potential safety risks by utilizing Gemba walks, in which leadership is fully exposed to the situations or scenarios in which such hazards may emerge.
- Enhanced Collaboration. Supporting all the advantages highlighted in this list, collaboration is at the heart of any successful construction project. Lean methodologies clearly advocate for collaborative processes, even providing the tools and frameworks needed to seek numerous perspectives and build these into key workflows.
Examples of Lean Construction in Practice
Many inspiring examples reveal how lean construction can improve construction outcomes, creating a safer and more efficient environment that consistently exceeds quality expectations.
- Turner Construction. Industry leader Turner Construction has a long history of completing complex projects while implementing innovative strategies. This company is transparent about its use of lean methodologies, even referring to itself as a lean construction pioneer. Turner highlights the New Canaan Library as an example of its lean processes in action, explaining that its construction management services produced a truly transformational space for New Canaan families. Additionally, Turner highlights LPS as one of its core solutions for “improv[ing] collaboration between different teams.”
- Mortenson Construction. Hiring lean innovation managers and other lean-oriented professionals, respected builder and developer Mortenson Construction has heavily utilized lean principles to complete major projects such as Chicago’s Home2 Suites Flagship Hotel, even managing to finish construction activities ahead of schedule. Mortenson makes extensive use of tried-and-tested techniques such as pull planning, 5S, and LPS.
Challenges in Implementing Lean Construction
Despite its many advantages and widespread popularity within global construction management, lean construction continues to face many challenges, especially surrounding implementation.
- Cultural Resistance. In lean construction, resistance to change is a common point of concern, calling for cultural shifts that move beyond traditional hierarchical structures and siloed strategies.
- Training and Education Needs. Those unfamiliar with lean strategies may struggle to adopt them without extensive training. This takes time, however, and, without proper training, team members are likely to revert to traditional solutions.
- Initial Investment. Between LCI-approved educational programs and internal training or materials, businesses may need to dedicate considerable financial resources to get lean strategies off the ground. Add consulting services or extra time for process analysis, and early investments can add up quickly.
Strategies and Steps for Implementing Lean Construction
Given the challenges and investments highlighted above, it is incredibly important to bring a strategic approach to implementing lean, to overcome resistance so that lean’s core advantages can be realized and ultimately, maximized. Implementation essentials include:
1. Provide Lean Training and Education
Success in lean construction is not possible unless there is maximum buy-in from team members, who need to understand what lean construction involves and why it’s important. Hence, the need for ongoing training, which not only introduces team members to the principles of lean but also reveals how these play out in the construction sector and how, specifically, they can contribute to this effort.
2. Implement the Last Planner® System (LPS)
LPS implementation may involve a lean coach or lean champion who can oversee the implementation and deployment processes, capable of facilitating training and guiding cultural change. LCI advocates for deployment plans, which provide a structured process and a “place to start.” This goes beyond lean training to include method selection, method goal identification, and the integration of selected methods into overarching project plans.
3. Start With Pilot Projects
Pilot projects can help overcome resistance to solutions such as LPS by revealing how these techniques play out in lower-risk situations and tightly controlled environments. When planning pilots, stick with smaller projects but ensure their duration is extended enough to accommodate all LPS phases. From there, lean coaches can guide pilot participants through core LPS processes such as milestone, phase pull, and lookahead planning, all while tracking metrics and seeking feedback.
4. Map and Analyze Processes
Mapping processes allow teams to identify constraints or bottlenecks, ultimately allowing them to design workflows that achieve lean construction’s core objective of waste reduction. This also helps teams “prioritize methods that add value to [each] project.” LCI advocates for the use of Conditions of Satisfaction (CoS) to define criteria and improve team alignment.
5. Leverage Technology to Support Lean Practices
A wealth of advanced technologies shapes the contemporary lean ecosystem, enhancing collaboration and even freeing up time through the use of artificial intelligence. While leaders should only select technological solutions that support lean thinking and specific project goals, solutions such as Building Information Modeling (BIM) and AI-powered analytics can go a long way towards identifying inefficiencies and streamlining critical processes.
6. Measure Performance and Pursue Continuous Improvement
Previously discussed frameworks can help bring continuous improvements into lean adoption, with performance monitoring revealing whether the core objectives of lean deployment are ultimately realized. This could involve a variety of key performance indicators (KPIs), along with strong feedback loops that reveal opportunities for improvement.
The Future of Lean Construction
Lean construction has come a long way in the last several years, but the lean revolution is just beginning. As this approach gains widespread acceptance, it is quickly becoming the industry norm, further amplified by emerging technologies and research-backed strategies.
Moving forward, lean construction will be shaped not only by cutting-edge tech solutions and data-driven opportunities, but also by cultural shifts surrounding sustainability and diversity. The future of lean is bright, and construction leaders are excited to get on board.
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