Lean construction is a combination of operational research and practical development in design and construction with an adoption of lean manufacturing principles and practices to the end-to-end design and construction process. Lean Construction required the application of a robust programmatic framework to all repair, renovation, maintenance, and or new build activities. While each project may be unique, the application of LEAN fundamental should be applied consistently. Lean Construction is concerned with the alignment and holistic pursuit of concurrent and continuous improvements in all dimensions of the built and natural environment: design, construction, activation, maintenance, salvaging, and recycling (Abdelhamid 2007, Abdelhamid et al. 2008). This approach tries to manage and improve construction processes with minimum cost and maximum value by considering customer needs. (Koskela et al. 2002 [1] )
The origins of many fundamental concepts of LEAN and LEAN construction date back in time.
Lauri Koskela, in 1992, challenged the construction management community to consider the inadequacies of the time-cost-quality tradeoff paradigm. [2] Another paradigm-breaking anomaly was that observed by Ballard (1994 [3] ), Ballard and Howell (1994a [4] and 1994b), and Howell (1998). Analysis of project plan failures indicated that "normally only about 50% of the tasks on weekly work plans are completed by the end of the plan week" and that constructors could mitigate most of the problems through "active management of variability, starting with the structuring of the project (temporary production system) and continuing through its operation and improvement" (Ballard and Howell 2003 [5] ).
Evidence from research and observations indicated that the conceptual models of Construction Management and the tools it utilizes (work breakdown structure, critical path method, and earned value management) fail to deliver projects 'on-time, at budget, and at desired quality' (Abdelhamid 2004). With recurring negative experiences on projects, evidenced by endemic quality problems and rising litigation, it became evident that the governing principles of construction management needed revisiting. One comment published by the CMAA, in its Sixth Annual Survey of Owners (2006), pointed to concern about work methods and the cost of waste:
"While the cost of steel and cement are making headlines, the less publicized failures in the management of construction projects can be disastrous. Listen carefully to the message in this comment. We are not talking about just materials, methods, equipment, or contract documents. We are talking about how we work to deliver successful capital projects and how we manage the costs of inefficiency." [6]
Koskela (2000) [7] argued that the mismatch between the conceptual models and observed reality underscored the lack of robustness in the existing constructs and signaled the need for a theory of production in construction. Koskela then used the ideal production system embodied in the Toyota Production System to develop a more overarching production management paradigm for project-based production systems where production is conceptualized in three complementary ways, namely, as a Transformation (T), as a Flow (F), and as Value generation (V).
Koskela and Howell (2002) also presented a review of existing management theory – specifically as related to the planning, execution, and control paradigms – in project-based production systems. Both conceptualizations provide a solid intellectual foundation of lean construction as evident from both research and practice (Abdelhamid 2004).
Recognizing that construction sites reflect prototypical behavior of complex and chaotic systems, especially in the flow of both material and information on and off site, Bertelsen (2003a and 2003b) suggested that construction should be modeled using chaos and complex systems theory. Bertelsen (2003b) specifically argued that construction could and should be understood in three complementary ways:
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While the term lean construction may have been coined by the International Group for Lean Construction in its first meeting in 1993 (Gleeson et al. 2007). ) Greg Howell and Glenn Ballard, there are instances of rigorous LEAN process thinking all the way back to the Arsenal in Venice in the 1450s, and the first person to truly integrate an entire production process, Henry Ford. At Highland Park, MI, in 1913 he married consistently interchangeable parts with standard work and moving conveyance to create what he called flow production. The public grasped this in the dramatic form of the moving assembly line, but from the standpoint of the manufacturing engineer the breakthroughs actually went much further. (Note: The founders of the Lean Construction Institute in 1997) both maintain that Construction in Lean Construction refers to the entire industry and not the phase during which construction takes place. Thus, Lean Construction is for owners, architects, designers, engineers, constructors, suppliers & end users.)
In any case, the term Lean Construction has escaped canonical definition. There has been a number of reasons for that. The body of knowledge has been in a state of development since 1990. Nonetheless, a definition is needed to be able to operationalize the concepts and principles contained in the philosophy. It is insightful to study the change of definition over time as that represents the evolution and advancement in the state of knowledge about Lean Construction.
The reference to Lean Construction as a proper noun is not an attempt to falsely distinguish it from other areas that focus on construction project management. It is a proper noun because it refers to a very specific set of concepts, principles, and practices that are distinct from conventional design and construction management practices .
A number of groups have proposed definitions: The International Group for Lean Construction; The Lean Construction Institute; The Associated General Contractors of America; Construction Management Association of America, and others. Researchers have also put forward definitions as foundation for their work and to invite others to add, modify and critique. A sampling is provided here.
Lean Construction is a “way to design production systems to minimize waste of materials, time, and effort in order to generate the maximum possible amount of value," (Koskela et al. 2002 [1] ). Designing a production system to achieve the stated ends is only possible through the collaboration of all project participants (Owner, A/E, contractors, Facility Managers, End-user) at early stages of the project. This goes beyond the contractual arrangement of design/build or constructability reviews where contractors, and sometime facility managers, merely react to designs instead of informing and influencing the design (Abdelhamid et al. 2008).
Lean Construction recognizes that desired ends affect the means to achieve these ends, and that available means will affect realized ends (Lichtig 2004). Essentially, Lean Construction aims to embody the benefits of the Master Builder concept (Abdelhamid et al. 2008).
"One can think of lean construction in a way similar to mesoeconomics. Lean construction draws upon the principles of project-level management and upon the principles that govern production-level management. Lean construction recognizes that any successful project undertaking will inevitably involve the interaction between project and production management." (Abdelhamid 2007)
Lean construction supplements traditional construction management approaches with (Abdelhamid 2007): (1) two critical and necessary dimensions for successful capital project delivery by requiring the deliberate consideration of material and information flow and value generation in a production system; and (2) different project and production management (planning-execution-control) paradigms.
While lean construction is identical to lean production in spirit, it is different in how it was conceived as well as how it is practiced. There is a view that "adaptation" of Lean Manufacturing/Production forms the basis of Lean Construction. The view of Lauri Koskela, Greg Howell, and Glenn Ballard is very different, with the origin of lean construction arising mainly from the need for a production theory in construction and anomalies that were observed in the reliability of weekly production planning.
Getting work to flow reliably and predictably on a construction site requires the impeccable alignment of the entire supply chain responsible for constructed facilities such that value is maximized and waste is minimized. With such a broad scope, it is fair to say that tools found in Lean Manufacturing and Lean Production, as practiced by Toyota and others, have been adapted to be used in the fulfillment of Lean construction principles. TQM, SPC, six-sigma, have all found their way into lean construction. Similarly, tools and methods found in other areas, such as in social science and business, are used where they are applicable. The tools and methods in construction management, such as CPM and work breakdown structure, etc., are also utilized in lean construction implementations.
If the tool, method, and/or technique will assist in fulfilling the aims of lean construction, it is considered a part of the toolkit available for use. A sampling of these tools includes: BIM (Lean Design), A3, process design (Lean Design), offsite fabrication and JIT (Lean Supply), value chain mapping (Lean Assembly), visual site (Lean Assembly); 5S (Lean Assembly), daily crew huddles (Lean Assembly).
The priority for all construction work is to:
Solutions that integrate construction planning, procurement, and project delivery are now readily available. The enable lean methods such as Integrated Project Delivery (IPD) and Job Order Contracting (JOC).
The early involvement of contractors and suppliers is seen as a key differentiator for construction so called 'best practice'. [10] While there are Trade Marked business processes (see below), academics have also addressed related concepts such as 'early contractor involvement' (ECI). [11]
Primary IPD team members include the owner, architect, key technical consultants, general contractor and key subcontractors.[ citation needed ]
Using IPD, project participants can overcome key organizational and contractual problems. The IPD approach to contracting aligns project objectives with the interests of key participants. IPD relies on participant selection, transparency and continuing dialog. Construction consumers might consider rethinking their contracting strategies to share more fully in the benefits. The IPD approach creates an organization with the ability to apply Lean Project Delivery (LPD) principles and practices. (Matthews and Howell 2005 [12] )
There are at least five principal forms of contract that support lean construction
Other papers explain Integrated Project Delivery (IPD) and IFoA. [12] [13] PPC2000, IFoA and 'alliancing agreements' were among the topics discussed at the 'Lean in the Public Sector' (LIPS) conference held in 2009. [18]
The examples and perspective in this article deal primarily with the United Kingdom and do not represent a worldwide view of the subject.(September 2010) |
In America, Job Order Contracting (JOC) uses explicit lean construction principles. JOC requires a long-term multi-party agreement, a collaborative environment, and a common data environment as signified by a locally researched detailed unit price book. More specifically JOC includes; direct owner leadership, adaptation of process to organizational requirements, locally researched, fully transparent and verifiable construction cost data, full regulatoryu compliance and auditability, focus upon programmatic processes applied to all associated construction, repair, renovation, or maintenance projects and work orders, collaborative and scalable cloud technology and the proactive integration of construction planning, procurement, and project delivery with a focus on value outcomes for all participants and stakeholders
In the UK, a major R&D project, Building Down Barriers, was launched in 1997 to adapt the Toyota Production System for use in the construction sector. The resulting supply chain management toolset was tested and refined on two pilot projects and the comprehensive and detailed process-based toolset was published in 2000 as the 'Building Down Barriers Handbook of Supply Chain Management-The Essentials'. The project demonstrated very clearly that lean thinking would only deliver major performance improvements if the construction sector learned from the extensive experience of other business sectors. Lean thinking must become the way that all the firms in the design and construction supply chain co-operate with each other at a strategic level that over-arches individual projects. In the aerospace sector, these long-term supply-side relationships are called a 'Virtual Company', in other business sectors they are called an 'Extended Lean Enterprise'.
The UK 'Building Down Barriers Handbook of Supply Chain Management-The Essentials' states that: 'The commercial core of supply chain management is setting up long-term relationships based on improving the value of what the supply chain delivers, improving quality and reducing underlying costs through taking out waste and inefficiency. This is the opposite of 'business as usual' in the construction sector, where people do things on project after project in the same old inefficient ways, forcing each other to give up profits and overhead recovery in order to deliver at what seems the market price. What results is a fight over who keeps any of the meagre margins that result from each project, or attempts to recoup 'negative margins' through 'claims', The last thing that receives time or energy in this desperate, project-by-project gladiatorial battle for survival is consideration of how to reduce underlying costs or improve quality'.
There are many differences between the Lean Construction (LC) approach and the Project Management Institute (PMI) approach to construction. These include:
Earned value management (EVM), earned value project management, or earned value performance management (EVPM) is a project management technique for measuring project performance and progress in an objective manner.
Project management is the process of supervising the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation, created at the beginning of the development process. The primary constraints are scope, time, and budget. The secondary challenge is to optimize the allocation of necessary inputs and apply them to meet pre-defined objectives.
The Project Management Body of Knowledge (PMBOK) is a set of standard terminology and guidelines for project management. The body of knowledge evolves over time and is presented in A Guide to the Project Management Body of Knowledge, a book whose seventh edition was released in 2021. This document results from work overseen by the Project Management Institute (PMI), which offers the CAPM and PMP certifications.
Lean manufacturing is a method of manufacturing goods aimed primarily at reducing times within the production system as well as response times from suppliers and customers. It is closely related to another concept called just-in-time manufacturing. Just-in-time manufacturing tries to match production to demand by only supplying goods that have been ordered and focus on efficiency, productivity, and reduction of "wastes" for the producer and supplier of goods. Lean manufacturing adopts the just-in-time approach and additionally focuses on reducing cycle, flow, and throughput times by further eliminating activities that do not add any value for the customer. Lean manufacturing also involves people who work outside of the manufacturing process, such as in marketing and customer service.
Construction is a general term meaning the art and science of forming objects, systems, or organizations. It comes from the Latin word constructio and Old French construction. To 'construct' is a verb: the act of building, and the noun is construction: how something is built or the nature of its structure.
Design–build, also known as alternative delivery, is a project delivery system used in the construction industry. It is a method to deliver a project in which the design and construction services are contracted by a single entity known as the design–builder or design–build contractor. It can be subdivided into architect-led design–build and contractor-led design–build.
Project delivery methods defines the characteristics of how a construction project is designed and built and the responsibilities of the parties involved in the construction. They are used by a construction manager who is working as an agent to the owner or by the owner itself to carry-out a construction project while mitigating the risks to the scope of work, time, budget, quality and safety of the project. These risks ranges from cost overruns, time delays and conflict among the various parties.
Design–bid–build, also known as Design–tender, traditional method, or hardbid, is a project delivery method in which the agency or owner contracts with separate entities for the design and construction of a project.
Target costing is an approach to determine a product's life-cycle cost which should be sufficient to develop specified functionality and quality, while ensuring its desired profit. It involves setting a target cost by subtracting a desired profit margin from a competitive market price. A target cost is the maximum amount of cost that can be incurred on a product, however, the firm can still earn the required profit margin from that product at a particular selling price. Target costing decomposes the target cost from product level to component level. Through this decomposition, target costing spreads the competitive pressure faced by the company to product's designers and suppliers. Target costing consists of cost planning in the design phase of production as well as cost control throughout the resulting product life cycle. The cardinal rule of target costing is to never exceed the target cost. However, the focus of target costing is not to minimize costs, but to achieve a desired level of cost reduction determined by the target costing process.
Construction management (CM) aims to control the quality of a project's scope, time, and cost to maximize the project owner's satisfaction. It uses project management techniques and software to oversee the planning, design, construction and closeout of a construction project safely, on time, on budget and within specifications.
Takt time, or simply takt, is a manufacturing term to describe the required product assembly duration that is needed to match the demand. Often confused with cycle time, takt time is a tool used to design work and it measures the average time interval between the start of production of one unit and the start of production of the next unit when items are produced sequentially. For calculations, it is the time to produce parts divided by the number of parts demanded in that time interval. The takt time is based on customer demand; if a process or a production line are unable to produce at takt time, either demand leveling, additional resources, or process re-engineering is needed to ensure on-time delivery.
Agile management is the application of the principles of Agile software development and Lean Management to various management processes, particularly product development. Following the appearance of The Manifesto for Agile Software Development in 2001, Agile techniques started to spread into other areas of activity. The term Agile originates from Agile manufacturing - which in the early 1990s had developed from flexible manufacturing systems and lean manufacturing/production.
Materials management is a core supply chain function and includes supply chain planning and supply chain execution capabilities. Specifically, materials management is the capability firms use to plan total material requirements. The material requirements are communicated to procurement and other functions for sourcing. Materials management is also responsible for determining the amount of material to be deployed at each stocking location across the supply chain, establishing material replenishment plans, determining inventory levels to hold for each type of inventory, and communicating information regarding material needs throughout the extended supply chain.
Integrated project delivery (IPD) is a construction project delivery method that seeks the efficiency and involvement of all participants through all phases of design, fabrication, and construction. IPD combines ideas from integrated practice and lean construction. The objectives of IPD are to increase productivity, reduce waste, avoid time overruns, enhance final product quality, and reduce conflicts between owners, architects and contractors during construction. IPD emphasizes the use of technology to facilitate communication between the parties involved in the construction process.
Lean project management is the application of lean concepts such as lean construction, lean manufacturing and lean thinking to project management.
The following outline is provided as an overview of and topical guide to project management:
Disciplined agile delivery (DAD) is the software development portion of the Disciplined Agile Toolkit. DAD enables teams to make simplified process decisions around incremental and iterative solution delivery. DAD builds on the many practices espoused by advocates of agile software development, including scrum, agile modeling, lean software development, and others.
ISO 21500, Guidance on Project Management, is an international standard developed by the International Organization for Standardization, or ISO starting in 2007 and released in 2012. It was intended to provide generic guidance, explain core principles and what constitutes good practice in project management. The ISO technical committee dealing with project management, ISO/PC 236 was held by the American National Standards Institute (ANSI) which had approved four standards that used Project Management Institute (PMI) materials, one of which was ANSI/PMI 99-001-2008, A Guide to the Project Management Body of Knowledge - 4th Edition.
Agile construction is an integrated system of principles and methods, and a philosophy of doing business adapted to jobsites and overall project delivery in the construction industry. It is born from agile manufacturing and project management, which is mostly used in manufacturing production, automotive and software developing teams. It is the application of the Toyota Production System to the construction industry, with two parallel paths: Measuring and improving productivity, as well as segregating and externalizing work through prefabrication and supply chain management.
Project production management (PPM) is the application of operations management to the delivery of capital projects. The PPM framework is based on a project as a production system view, in which a project transforms inputs into outputs.