Introduction

The term referred to as Lean Construction aims to reduce overproduction, minimise handling, storage, transportation, or remove processes that do not add value. The Construction industry recognized the potential of BIM and lean Construction’s interaction to reduce waste on construction projects.

When considering the global construction growth, for example, a single country such as China used more cement in two years than the United States in the entire 20th century^[1]. There is an increased need for a more environmentally friendly construction process, which encourages new project management techniques.

Early research was mainly aimed at speeding up Construction and improving overall productivity by introducing new technologies, tools and equipment. However, the Lean Construction project management can be strengthened by applying BIM, delivering improved efficiency by the better information-driven project management.

BIM is an information management instrument, not a project delivery method, but when implemented jointly with Lean Construction, it can support pull-flow in a mutually created process model. Lean Construction’s synergy with information management system (BIM) supports pull-flow scheduling in a collaboratively constructed, live and actionable process model for the project. The combined system strengthens the program’s collaborative co-production, based on operation and resource dependencies, rather than concentrating on inputs to outputs but not the flow of resources or value to the client with critical path programmed using static ‘ideal world’ project schedule. ^[2]

In this journal, the author explores the principles of Lean Construction and the relationship with BIM

Lean Construction

In the 1990s, identified as an outcome of the Toyota Production System (TPS), Lean manufacturing, also referred to as lean production, led to lean thinking in the construction industry. Lean thinking focuses on identifying and establishing expected targets and seeks to streamline the project schedule.

As part of Toyota’s TPS, the pull-and-push Kanban planning system has been established to determine when, how much, and where to produce.

The use of the pull-and-push process can lead to considerable reductions in the work process. Due to the high-capacity utilization and reduced scheduling activity, the pull-and-push process’s use leads to an improved process flow.  ^[3]

Push-pull in Construction

Many Architecture Engineering and Construction (AEC) projects operate in a push system manner. The preconstruction team determines when to send (push) material to sites based on the original project schedules or historical patterns.

Such strategy often leads to site excess inventory, which equates to waste. The resulting waste depicted in Figure 1 comprises lost time due to extra handling of material, housekeeping and safety issues, damage or loss of material, and the cost of carrying inventory and the resulted environmental impact.

Figure 1 – Push system. ^[4]

Projects with lean construction methods encourage project teams to operate in a pull system fashion. Such an approach, shown in Figure 2, where the task team dictates when to pull material orders to the site, allowing them to be planned for manufacturing or set for just-in-time delivery.

Figure 2 – Pull system. ^[4]

Demand, driven by the project team, is best to plan for what, when and where the material is needed.

A pull system in a manufacturing environment is commonly referred to as lean manufacturing; in Construction, it is commonly referred to as the Last Planner or Lean Construction System. ^[4]

Three distinctive models of lean principles

Architecture Engineering and Construction (AEC) industry transforming from lean production, identified three distinctive models of lean principles:

Last Planner System (LPS)

Two architects and engineers developed the Last Planner System (LPS), Glenn H. Smith and David L. Miller, who founded the Lean Construction Institute. Smith and Miller noted that projects are planned from the outset by a project manager who predicts how each phase of the project will progress in traditional construction management.

In LPS, task teams at each stage of a project are engaged in the planning process as their involvement approaches. These individual task teams are the ‘last planners’ who can help define how long each stage of a construction project will take and recognize potential issues. ^[5]

The LPS  encourages collaboration, improving the interaction between task teams who commit to specific delivery schedules.

The LPS involves five distinct segments:

The Master Schedule

Appointing Party and Lead Appointed Parties initially define the Master Schedule, not dissimilar to traditional construction project management; this stage entails planning a project programme identifying key milestones.

Phase Planning

This stage is significantly different to traditional construction management. At this stage, the task teams involved in each of the key project milestones collaborate to map out how to complete the phase on time. The task teams might use the concept of ‘pull planning’, working backwards from the milestone deadline to ensure the parties involved can complete their responsibilities in time for the next phase to begin.

Look Ahead Planning

Look ahead planning typically involves a weekly review of the task teams’ four to six weeks are look-ahead programme, reviewing likely causes of constraints and predicted delays, considering how to overcome these constraints.

Commitment Planning

The LPS relies on a level of peer pressure. Typically each week, individual task teams commit to complete specific tasks. Such direct voluntary commitment incentivises the individuals to complete the work they have promised to deliver.

Continual learning

A final facet of the LPS is frequently meetings to discuss what has gone well and what went wrong to learn and improve.^[6]

Target value design

The Target Value Designs (TVD) process was created in the 1930s when manufacturers used it to reduce their production costs so that their final product would be in line with market prices. The TVD process continually optimizes the Design to achieve the desired end product without running out of time or cost.

TVD focuses on reducing the cost of a project without reducing the end product’s quality or extending the timetable. The team sets a cost target for the Design and Construction, which is usually the current estimate. TVD aims to achieve this goal by defining costs as a design limitation and not due to design. ^[7]

Figure 3 – Target Value Delivery ^[7]

A TVD project’s characteristics are shown in Figure 3; the process is only successful if the entire team is engaged and united by the goals set early in the project. For TVD to be effective, or even possible, commitment from all task teams is required. The target cost must never exceed the target’s total cost; therefore, continuous monitoring is required.

Lean project delivery system

The Lean Project Delivery System (LPDS) began in 2000 from academic and practical research and is continually developed through experimentation. It is a model for managing projects, where Project Definition is characterized as a process of aligning finance, methods and constraints; the system schema is depicted in Figure 4

LPDS is committed to waste removal and optimization of the design, delivery and construction process through a project-based production system to leverage the energy, system’s potential – efficient, cost-effective, high quality and clean. In the Lean Project Delivery System, it is accepted that the role of the project delivery team is not only to provide what the customer needs but also to help the client decide what they want.

First experiments have focused on the definition and design phase of projects, applying concepts and procedures derived from the Toyota Product Development System, most notably target value design and set-based design.

Set-Based Design

Set-Based Design commonly referred to as a set-based design innovation or set-based concurrent engineering. It is a product development approach where teams consider a wide range of design alternatives (a “set”) and systematically reduce the set to a final, often superior choice. ^[8]

LPDS has been adapted for use in the construction industry and integrated with BIM and relational forms of contract. ^[9]

Figure 4 – Lean Project Delivery System ^[9]

The LPDS sets the need for understanding purpose as a critical part of a successful project. In his journal G. Ballard (2008) suggests that although the perception that the project team has no direct connection with the client’s purpose, the connection between purpose and constraints exists. Therefore a better understanding of purpose could have a direct impact on cost.

LPDS has proven to be an effective productivity improvement method. Despite enormous benefits, the construction industry struggles with the effective implementation of LPDS, especially in achieving Lean Construction (LC) principles like improving the visualization and maintaining an effective flow of information. According to a study by Aslam et al. ( 2021),^[10] Virtual Design and Construction (VDC) integral with BIM processes provide opportunities for the construction industry to implement LPDS effectively.

In the AEC industry, the defined processes are based on information from different stakeholders; the quality of information is critical for process reliability. According to Aslam et al. ( 2021), the benefits of automation, rapid generation of design and plan alternatives, online communication, and better visualization offered by VDC can significantly impact the effective implementation of LPDS.

In closing

This journal investigated lean construction principles and their relationship with BIM, considering lean workflows implementation and optimisation.

My research reveals several barriers which impede the implementation of lean Construction in the AEC industry. The most significant is the cultural and behavioural aspects of change, followed by the lack of visualization capabilities (although steadily improving) and limited capabilities for sharing reliable information. Though from the author’s experience, the use of Common Data Environment (CDE) has become common, helping secure and efficient information exchange.

Subsequent barriers reported by Aslam et al. ( 2021) are deficiency in the rapid development of alternative designs,  difficulties in identifying target cost, communication, trust among project teams and lack of reliable lean assessment methods.

A pull system is the most commonly implemented lean construction technique, typically applied during material procurement to effectively support projects’ productivity and reduce overall costs. The author recognised the pull system’s potential when implemented during project schedule planning as the most significant, process if implemented, can improve clarity and reduce overproduction of information and re-work throughout the project delivery chain.

[1]        Vaclav. Smil, Making the Modern World : Materials and Dematerialization. Wiley, 2013.

[2]        Paramjit, “Production management system supporting LEAN and BIM ,” VisiLean, Apr. 05, 2019. (accessed Apr. 03, 2021).

[3]        P. Nguyen and R. Akhavian, “Synergistic Effect of Integrated Project Delivery, Lean Construction, and Building Information Modeling on Project Performance Measures: A Quantitative and Qualitative Analysis,” Advances in Civil Engineering, vol. 2019, 2019, doi: 10.1155/2019/1267048.

[4]        D. Darrow, “Site Logistics Planning = Increased Productivity + Cost Savings,” Oct. 06, 2019. (accessed Apr. 03, 2021).

[5]        A. O. Alsehaimi, P. T. Fazenda, and L. Koskela, “Improving construction management practice with the Last Planner System: A case study,” Engineering, Construction and Architectural Management, vol. 21, no. 1, pp. 51–64, 2014, doi: 10.1108/ECAM-03-2012-0032.

[6]        A. O’Malley, “The Last Planner System ®: how to get started – PlanRadar,” Oct. 16, 2020. (accessed Apr. 03, 2021).

[7]        T. Werth, “Using target value design: a short introduction,” CRB. (accessed Apr. 03, 2021).

[8]        B. Toche, R. Pellerin, and C. Fortin, “Set-based design: A review and new directions,” Design Science, vol. 6. Cambridge University Press, 2020, doi: 10.1017/dsj.2020.16.

[9]        G. Ballard, “The Lean Project Delivery System: An Update,” 2008. Accessed: Apr. 03, 2021. [Online]. Available: www.leanconstructionjournal.org.

[10]       M. Aslam, Z. Gao, and G. Smith, “Integrated implementation of Virtual Design and Construction (VDC) and lean project delivery system (LPDS),” Journal of Building Engineering, vol. 39. Elsevier Ltd, p. 102252, Jul. 01, 2021, doi: 10.1016/j.jobe.2021.102252.