Rick Bell | Content Strategist | June 7, 2024
Scheduling has been among the most important construction project management disciplines for decades. In recent years, the industry was introduced to lean construction, a series of means and methods that originated within industrial manufacturing. Lean construction looks to shift planning and scheduling execution processes toward a framework of high-frequency collaboration and continuous jobsite workflow. Lean construction scheduling has gained favor in many construction circles, though it’s not universally accepted.
This article will explore the benefits and challenges of lean construction scheduling and best practices that can improve project efficiency and productivity. It will also cover how to apply lean techniques to the scheduling process and the tools that can help create a lean construction schedule. By the end of this article, you’ll know more about how lean construction scheduling can enhance your project management processes.
Lean construction scheduling is adapted from an industrial manufacturing process framework aligned with the Toyota Production System. This framework centers on four foundational concepts: What should be done? What can be done? What will be done? What did get done?
These concepts manifest themselves within five layers of production planning, where a project schedule is developed at a high level and then broken down into interval production details.
Event one: What should be done, is where the project team develops a high-level master plan or promise of the project.
Event two: Also under what should be done, is where the project team takes the master plan and collaboratively breaks it down into a pull plan (more on that below) or phase plan.
Event three: What can be done, is taking a phase/pull plan and further detailing jobsite workflow with “make-ready planning,” also called look-ahead planning.
Event four: What will get done, narrows the planning window even further into a “weekly work plan,” where multiple trades must execute against their commitments.
Event five: What did get done, encompasses the production tracking, performance measurement, and learning associated with field production.
Key Takeaways:
Lean construction scheduling is a process framework to help project teams arrive at a plan that meaningfully represents the details of managing jobsite production. The framework is designed to aid a team of cross-functional stakeholders through the development of a high-level master schedule and then further detail that schedule with planning events focused on shorter and shorter production intervals. Lean construction scheduling is intended to be highly collaborative, with participation from all levels of the project team.
In practice, the tools that support these processes can be analog or digital. The process often starts with a wall of sticky notes that represent the five layers of production planning: master planning, the pull/phase schedule, make-ready/look-ahead planning, weekly work planning, and production tracking/learning/reporting. The finished schedule can then be entered into a spreadsheet or another type of software program.
Critical path method (CPM) planning and scheduling has been a tried-and-true industry standard since its use during the Manhattan Project. While it shares many of lean construction scheduling’s core attributes, it differs in one main way: CPM schedules tend to visualize the sequences of work (activities) in a Gantt chart, while lean construction schedules typically visualize work (tasks) on a sticky note wall.
Both visualization methods are valuable. Moreover, there’s an increasing desire to connect the “activities” that belong to the CPM contract schedule with the “tasks” that belong to the field team’s production details.
Traditional construction scheduling includes:
Lean construction scheduling emphasizes:
It’s important to note that the CPM and lean methods don’t have to be mutually exclusive. Many construction teams choose to blend methods; the key being a structural connection between the CPM’s activity network and the field’s task production details.
The primary goal of lean in design and construction is to deliver maximum value to the customer without the waste that typically plagues project delivery.
Lean scheduling and its specific focus on jobsite team coordination centers on squeezing out downtime between trades and reducing the tendency for equipment and workers to sit idle. Jobsite workflow becomes more reliable as labor, equipment, and materials (LEM) arrive just in time and the waste of redundancy, overproduction, and overprocessing are eliminated.
One of the main advantages of lean scheduling is the collaborative aspects of planning and production tracking, whereby the commitments between trades are exposed and managed in short interval execution windows. Are we doing what we said we would? is a primary measurement, also called planned percent complete (PPC). This metric helps showcase how individual trades are trending across the life of a project. Because it’s measured each week, PPC reinforces continuous improvement as an outcome to maximize both project and customer value.
The process framework of lean construction scheduling provides a structure that project teams can use to focus their planning and execution efforts into finely tuned production windows. While continuous improvement is a habit of any good project team, lean scheduling reinforces these habits by consistently requiring multiple organizations (trades) to jointly plan their collective task assignments in a shared planning board.
Lean scheduling sets out a detailed timeline and assigns the most qualified people to each task, boosting efficiency. It encompasses three main methods.
Pull planning is a construction scheduling technique that establishes key project milestones, and then works backwards to determine the sequence of events to achieve those milestones. Often referred to as “pulling the plan,” this technique relies on input from multiple stakeholders, strong collaboration, and the ability of the team to work backward to arrive at start dates.
The last planner system is a task/field planning system in which the person closest to the work is involved in creating the workflow and assigning realistic timelines. It focuses on taking a phase/pull plan and then breaking it down into make-ready/look-ahead planning, weekly work planning, and production measurement and tracking. It includes identifying and removing constraints, commitment to specific tasks that are written on sticky notes on a planning board, daily coordination, planned percent complete reporting, and learning from what was done.
Work structuring is a term that is used to describe the effort of integrating task product and processes throughout the project delivery process. Part and parcel of make-ready planning and weekly work planning, work structuring is a way of configuring the planning board to optimize the configuration of jobsite workflow.
Lean construction scheduling is designed to reduce waste and optimize LEM. If the sequencing of how construction trades are moving through production is as efficient as possible, and it’s clear who is doing what and when, the result will be improved project outcomes. The other benefits include:
Construction crews are expected to become more efficient over time because they’re often performing the same tasks over and over during a project. The benefits of lean scheduling are evident as productivity increases, cost efficiencies improve, and profits go up.
Lean construction scheduling isn’t new—it was developed in the early 1990s. But its application by project teams continues to be a mixed bag. Among the challenges individual project teams may face are the following:
Many still don’t grasp the concept that lean construction scheduling is a journey, not a destination.
A poorly designed schedule affects the quality of work and can result in overworked teams, mistakes, and rework, which wastes valuable time and materials. Adapting a lean mindset to construction scheduling can identify ways to help eliminate waste and continuously improve a project’s productivity.
Adopting lean principles, such as pull, make-ready, look-ahead, and weekly work planning, is a culture shift. General contractors and other stakeholders may have spent much of their career following a specific set of traditional roles and responsibilities. Lean construction techniques often require that participants be trained for new roles, such as the skilled facilitators who can orchestrate pull or LPS sessions.
Adherence to any process requires buy-in. Lean construction scheduling ideally calls for a greater community of jobsite participants to be intimately involved in both developing and maintaining the project plan. Failure to get collective jobsite buy-in will limit lean scheduling’s overall value.
It’s not enough to just identify a construction project’s value proposition. Managers also need to map, and then clearly communicate, that value as crews progress through a project so that team members can check themselves against it and apply it in the job’s next phase.
Lean construction scheduling is structured to eliminate waste by reducing delays and rework, often caused by inefficient processes, mismatching workers with job tasks, and poor communications and coordination.
Projects consist of a variety of processes happening at the same time. When those processes are disrupted or overlap, teams get in each other’s way and make each other wait. Lean construction scheduling can optimize project workflows.
As mentioned earlier, pull planning is a construction scheduling technique that establishes key project milestones, and then works backward to determine the sequence of events to achieve those milestones. It requires a skilled facilitator to help the project team collaboratively work backward from key milestones to arrive at start dates.
Construction scheduling software, as the name suggests, helps construction professionals create and manage project schedules, track project timelines, allocate resources, and monitor overall progress.
PDCA, short for plan, do, check, and act, is a simple and effective approach for monitoring a construction project’s progress, adjusting to problems, and looking for ways to improve. The PDCA technique can be applied daily, weekly, or monthly.
No matter which scheduling methods are used, continuous improvement is a foundational habit of great project teams. However, it’s worth considering what structural process framework your organization puts in place to reinforce these habits. Lean scheduling’s adherence to both pull and LPS processes can be a welcome addition to traditional planning and scheduling practices.
Adopting lean techniques can help construction firms comply with green building practices now required of the industry and improve their overall environmental sustainability. How? By squeezing out physical waste, improving machinery efficiency, and optimizing the construction schedule to reduce the number of resources a project consumes and emissions it generates.
Lean construction takes a client-centric approach, which results in increased productivity and profits, while building a framework for continuous improvement. Creating a culture of collaboration focused on the customer journey and experience helps ensure that, rather than mimicking slow, convoluted internal structures, teams are organized to deliver value to the client.
Applying lean construction to a traditional CPM schedule bridges the gap between back office, front office, and field stakeholder groups. Understanding lean principles also improves efforts to build more sustainably while eliminating waste.
The first lean construction tools were analog: pen, paper, and sticky notes on a wall. Two problems with that approach were limited mobility and inability to scale. Lean construction software puts continuous improvement aids into the hands of all stakeholders anytime and anywhere. The software becomes the communication tool rather than the unmovable note wall. Instead of having to always walk into a trailer, workers get key project information on a mobile device instantly, at a glance.
Like a traffic light’s red, yellow, and green signals, visual management tools on construction sites use intuitive, visual aids to convey performance, progress, warnings, and other information, clearly and concisely.
Once visual representations are in place, simulations will show schedule progression, taking a three-dimensional rendering of an asset and tying it to a two-dimensional schedule. And when components of the schedule, activities, and tasks are tied to elements of the model, that’s 4D.
Lean construction used to be an analog process. But with advances in cloud technology, data availability, and construction project management tools, lean and critical path method scheduling can now complement each other.
Oracle Primavera Cloud takes the analog process and moves it into a digital realm. Want to build traditional CPM schedules? Oracle Primavera Cloud software has it covered. Want to use lean construction means and methods? Oracle Primavera Cloud covers that, too. There’s no need to pay extra for API integrations to build CPM or lean schedules using different tools.
What is lean design in construction?
Sometimes referred to as value engineering, lean in design eliminates waste occurring from a lack of collaborative planning. It diminishes the siloed thinking and rework that result from conventional project delivery methods. Bringing lean approaches to the design phase can improve the success of construction projects.
What are lean techniques in construction management?
There are six tenets of lean construction, according to the Lean Construction Institute: respect people, optimize the whole, eliminate waste, focus on flow, generate value, and continuous improvement. Under this approach, knowledge and work silos are broken down and reorganized for the betterment of the project, rather than for individual participants.
What is lean pull planning?
As defined earlier, pull planning is a lean method in which personnel, materials, information, and equipment arrive only when they’re needed to maintain the flow of the production process. It’s also a method of planning construction projects by establishing a project deliverable and completion date and then working backward to outline each step needed to get there.
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