Lean manufacturing is a management philosophy foundationally built on creating value. Major manufacturers rely on lean manufacturing to eliminate waste, improve efficiency, and provide higher value to customers. Many firms also report improved employee morale from the results achieved.
Implementing lean construction has been gaining traction over the last several years as more MEP contractors realize the benefits of applying lean principles to construction. The concept is relatively simple, maximize client value while minimizing waste in the process. However, the proper execution of the lean can be challenging to implement. For example, lean construction involves an entirely different approach to project delivery from traditional stick building construction techniques.
Lean Manufacturing Definition
Lean manufacturing involves defining processes and tools that eliminate waste from production. Byproducts of lean manufacturing include improved efficiency, effectiveness, and profitability.
Lean manufacturing is an adapted concept of the Toyota Production System (TPS) and its four principles. Waste elimination and continuous improvement are the primary core tenets of lean manufacturing.
Hurdles to Applying Lean in Construction
Unlike manufacturing, one of the difficulties in applying lean thinking to construction is that traditional stick building doesn’t always occur in a controlled environment, leading to more significant variations, making predictable and reliable workflows challenging to achieve. Another hurdle is that there isn’t one set method or process to achieve lean. Several approaches have been developed in an attempt to translate lean thinking to construction. A few tools and systems include Building Information Modeling (BIM), the Last Planner System, Kaizen Events, Integrated Project Delivery, and the 5s process. Many of these are used independently or jointly to implement lean practice in construction projects.
What’s critical to achieving lean construction goals are to cut costs, reduce construction schedules, increase productivity, and manage projects better. These principles drive your team to take a greater holistic approach to project delivery and better quality.
So what are the principles that make Lean work? This article highlights the five key lean manufacturing principles and their benefits to manufacturers, customers, and most importantly, in construction.
The 5 Key Lean Manufacturing Principles
1. Identifying Value from the Client’s POV
What do your customers value? Value is directly linked to what a customer will pay for your product. From a lean perspective, identify “the why and what” that drives your customers’ value.
Your client’s true values in a construction project typically go beyond delivering the plans and specs’ requirements. The actual value is more than completing the project on time and within budget or with high quality. This requires a customer-focused approach that is best achieved by establishing a relationship with the client. This collaborative relationship should include all stakeholders (owner, architect, engineers, general contractor, subs, and suppliers) collaborating at a high level.
Identifying client values should start early in the conceptual planning phase of a project and carry through the lifecycle of construction. The crucial point here is for you to understand what your clients want and why they want it to ensure the project team can manage expectations and best deliver on value needs. All stakeholders must have a deep level of trust to successfully implement lean practices. Understanding values and sharing them across the stakeholder group is essential.
2. Identify the Value Stream
The value stream consists of what the client values from their perspective. Once you’ve identified their values, its’ time to identify the processes necessary to deliver the value stream. The process steps should be mapped out along with what activities are required. Consider labor, time, materials, and equipment for each identified activity. Part of this process is identifying steps that don’t add value, and these should be eliminated.
If steps require new technology or prefabrication, your team should flag these opportunities for improvement.
3. Achieving Flow of Work Processes
The goal of lean construction is to achieve a continuous and synchronized workflow that brings predictability. Similar to manufacturing, production stages are performed in order. To achieve high flow, all stakeholders need to communicate and collaborate to avoid disruption.
Downtime and rework cause excessive cost overruns. Avoiding delays, whether workers are waiting or work waiting for workers, is critical. Splitting a project into distinct production zones can optimize contractor productivity so they can finish tasks on-schedule. With multiple stakeholders, communication across teams is essential to make adjustments if one stage of production falls behind or pushes ahead of project schedules. The lean principle emphasizes that you must avoid the workers waiting for work scenarios and pitfalls.
4. Using Pull Planning and Scheduling
Stakeholder collaboration is essential in lean construction because pull planning is performed by the subcontractors performing the work. They are the most knowledgeable in determining their capacity and performing tasks that heavily influence the project schedule. Subcontractors must communicate effectively with other dependent subcontractors or customers downstream to coordinate schedules and handoffs.
Removing Waste in Construction
As mentioned earlier, Lean construction is accomplished by significantly eliminating waste, and there are eight significant types in construction. A popular acronym has been used for individuals to remember these because they spell and cause DOWNTIME.
Defects – This is anything not done correctly the first time, which results in rework – Change Orders. Materials, labor, and time involved cause significant waste.
Overproduction – When work is completed ahead of schedule and before the next task in the sequence is ready to start. Workers are typically sitting around or not prepared to begin their work.
Waiting – Materials delayed to the jobsite or schedule slippage from workers not completing work on-time have ripple effects on workflow and cause contractors to wait for the green light to move forward.
Not Utilizing Talent – Ensuring the right talent, skills, and knowledge of workers assigned to tasks is essential. With the current labor shortage, junior electricians or contract labor shouldn’t be assigned senior-level tasks. This can cause mistakes, rework, and other waste.
Transport – Workers, equipment, and materials transported to the jobsite off-time and off-schedule can cause severe delays and waste. This is also referred to as the transmission of information with no added value.
Inventory – In lean construction, you want to move toward “just in time” inventory instead of “just in case” inventory. Prefabricated materials off-site and delivered just-in-time for assembly substantially helps create efficiencies on the job site.
Motion: Includes eliminating unnecessary movement across the jobsite for materials and tools by strategically addressing the waste involved in preventing multiple trips across the jobsite.
Excess Processing: Excess processing is typically created when there are inefficient double-checks for defects or inventory or unintentional extra processes. Over-processing can be eliminated by having a singular QC process.
5. Continuous Improvement & Perfection
The final lean manufacturing principle is seeking continuous improvement and achieving the lofty goal of perfection. Lean thinkers look for opportunities for improvement in each part of the value stream. And it doesn’t conclude at one project; it involves continually making improvements across multiple projects to eliminate waste and perfect your lean construction process.
Lean principles go beyond manufacturing and can help your construction firm realize many other benefits: improving team efficiency, inventory management, client interaction, and satisfaction. Other valued-adds include reducing costs and increasing work safety.