Construction Management & Economics: Lean Construction - Literature review Example

Lean construction Literature review The phrase "Lean Construction" was first coined by the International Group for Lean Construction at its inaugural meeting in 1993 (Gleeson et al. 2007). Lean construction is a method applied in the process of project delivery and is based on a waste-minimizing and value maximizing production management principle. In the construction industry this principle acquires a still lager dimension in that the approach is adopted through the whole process of manufacturing process design, planning, supply management and assembling. Lean production as associated with management is a systemic approach to minimizing losses or waste and maximizing value creation so that the subsequent techniques are refined to achieve a degree of sophistication in preconceived management settings. The following four aspectual phases have been suggested in modern literature on the subject as more perceptive in terms of design, performance, delivery and control. The construction facility and its delivery have to be designed and planned in a manner that takes into consideration the customer’s purpose and need. The rationale for positive iteration is emphasized so that negative iteration is minimized as far as possible. Designing the structural perimeters of the project in a manner to achieve value at the highest possible level and minimize waste at the delivery stage. This is essentially associated with the process facilitation because when construction projects are designed processes become complex as the delivery phase comes closer. Total performance concept is emphasized as a measure aimed at improving the qualitative outcomes. Thus project performance as a whole is much more important than cost reduction measures and relative speed. Controlling processes and systems is central to the monitoring task in lean construction. Thus there is an essential effort to measure and improve the performance of these processes and systems. It was Ohno, a production engineer at Toyota who for the first time broke through the conventional barrier between manufacturing and construction and introduced the concept of production design in the construction industry as a useful tool. Lauri Koskela’s (1992) seminal work successfully challenged the conventional trade-off paradigm of time, cost and quality and questioned the credibility of sticking to an otherwise out-of-tune conventional approach to construction. Abdelhamid (2007) suggests constant and simultaneous improvements in all related dimensions of the environment, both built and natural, thus rendering the construction project’s delivery as a holistic process. He places emphasis on each activity from beginning to the end – designing, building, activating, maintaining, salvaging the process and then recycling. Koskela has pointed out the existence of a mismatch between the concept based models and the reality as observed in the natural environment (2000). His theoretical underpinnings underscored the fact that the existing conceptual and theoretical models lacked the vigor that was essential in the production theory of the construction industry. In other words Koskela was suggesting the need for a more robust production system like that of Toyota’s. Toyota’s Production System was marked by revolutionary production paradigm that underlined the very management process form beginning to the end. The overarching principle behind its success is determined by the fact that Ohno believed in a systemic process of evolution in the process of production management in its practical applications. Thus the Toyota’s System was used as the stepping stone to build a new system that reflected the ideal three-tier combination – transformation, flow and value. The system was subsequently expressed as an equation though the equilibrium paradigm was more difficult to establish. Next, Koskela and Howell (2002) went on to develop a more holistic review of the weaknesses of the existing theory so as to identify and construct a set of theoretical and conceptual constructs that invariably are related to the planning, implementation and control processes in production and construction management. These concepts have helped a smoother process of evolution of the literature on the subject of lean construction along with the development of an inevitable correlation between research efforts and the practical reality. Lean construction is in fact the outcome of a rigorous effort by individual researchers to identify the significance of lean manufacturing principles as applied in physics to construction related production systems. Thus the logical three-tier of transformation, flow and value generation has acquired a very important dimension in the current literature on the subject. The end-to-end design and construction processes in lean construction have been considered as a paradigm shift from the orthodox to the unorthodox. Koskela’s repudiation of the time, quality and cost trade-off paradigm was further reinforced by subsequent research undertaken into its practical environment related failures by Ballard (1994) and then Ballard and Howell (1994). According to their research findings that an increasing number of failures of project plans was due to the fact that in a number of instances the degree of variability in project progress was not properly factored into the plan. Constructors and managers of projects were much less aware of the variability’s impact on the week’s work plan and its scheduled end. Thus many tasks planned for the week were either abandoned or just continued into another week ahead. This discrepancy produced a number of other anomalies such as constrained improvement and quality in production management processes (Ballard and Howell, 2003). According to Howell and Ballard (1994) only 50% of the total tasks on a weekly work plan could be finished with any amount of success while the rest was not accomplished. According to Abdelhamid (2004) the existing conventional conceptual models on managing construction projects show that they take work schedules, value generation for the customer and critical path analysis much less into account in the process of managing the project. Thus delivery related bottlenecks further delay the delivery, increase budgeted money and reduces quality (Abdelhamid, 2004). However Abdelhamid doesn’t point out the existence of a negative correlation between delays in work schedules and motivation of staff, especially managers. The tendency of the staff to be demotivated and increasing costs were considered by the Toyota System in its analysis of the workplace impact on productivity. The only difference is that it’s wholly about manufacturing and not construction. Indeed Koskela, Howell, Ballard and Abdelhamid all paid attention to the fact that efficient project delivery depended a number of endogenous and exogenous variables. For instance the endogenous variables such as resource mobility between two operations and the swiftness with which resources could be switched between two uses could affect the lean construction related outcomes, especially the delivery parameter. It’s here that the customer satisfaction issue plays a pivotal role. As for exogenous variables government regulations could have such a far reaching impact on delivery. The cost and quality parameters are then essentially influenced by these variables. Ohno’s approach is very significant against this backdrop due to the fact that waste is exceptionally high in many instances. According to Ohno increasing pressure on the task by trying to reduce cost and time is counterproductive. That’s where lean construction succeeds. In other words as in lean production or manufacturing, in lean construction too there must be a perpetual monitoring process that would identify and successfully mitigate waste centers. This doesn’t mean that pressure has to be mounted on tasks or activities (Day, 2008). The theoretical and conceptual contingency models of convergence/divergence that are used by modern designers and planners are essentially loaded with waste minimizing and utility maximizing paradigms though the extent to which they can be regarded as successful models for delivery related efficiencies has been a vague idea. For instance four principles can be identified from Ohno’s approach to be applied to waste minimization and efficiency maximization. There must be a clear set of goals for the delivery process under lean construction. Lean construction must be aimed at maximizing performance for the customer at the project level, The product and process must be designed as process of concurrence. The control procedures in production are applied coinsistently throughout the lifecycle of the project. Successful delivery is not only based on efficiency but also on the quality of the final product delivered to the end-user. Assuming a degree of independence enjoyed by the quality planner there is much more to be desired in respect of such concepts like Kanban and Kaizen as they occur in an exclusively lean construction context. The concept of Kanban has been proposed by recent researchers in lean construction for its impact on Just-In-Time (JIT) supplies procurement. However Koskela does not place emphasis on Kanban as an inclusive concept because in JIT stock movements can be well monitored to achieve cost efficiencies through effective stock control measures while it is not relevant for lean construction due to the fact that the latter utilizes materials only for the project of which the life cycle can be very short. However critics point out that Kanban is equally relevant in project management and lean construction because it helps to minimize expenses on maintaining stocks of material. But nevertheless there is an equally strong argument against Kanban in lean construction. The current literature suggest that construction materials are usually bought in bulk with huge discounts and therefore buying in smaller quantities would entail higher costs. On the other hand Kaizen refers to the standard Japanese manufacturer’s practice of continuous improvement of the product. This practice is related to quality circles. Japanese manufacturers have a habit of forming quality circles as informal units within the organization. The main task of a quality circle is to identify quality related constraints and suggest ways and means to overcome them. Their meetings are informal gatherings, usually during lunch or tea. While Ohno placed much emphasis on this concept Koskela, Howell and Ballard did not place much emphasis on it because according to them Kaizen is an exclusive concept related to manufacturing and not to production management in construction. Mastroianni and Abdelhamid (2003), Salem et al. (2005) identify Kanban and Kaizen as parametrically significant production flow control techniques. Particularly they emphasized the significance of Kaizen in respect of project deliverable efficiencies. The latter idea has gained momentum with the supporters of lean construction. The modern theoretical and conceptual underpinnings of contingency models of convergence/divergence on lean construction methodology suggest a holistic approach centered on the above mentioned three-tier combination - transformation, flow and value. In fact it is Abdelhamid who advocated the three-tier combination approach though modern researchers have expressed doubt about achieving qualitative paradigm shift in transforming the construction process from one of general to lean because there is very little by way of freedom available to the project manager to alter plans ones the project gets under way. Liberal minded advocates of the Kaizen concept agree that in the absence of operational freedom for the manager there is very little by way of effective decision making that a manger can accomplish without consulting the whole management of the project. In fact both Abdelhamid and Salem acknowledge the existence of substantial constraints in adopting the concept of Kaizen in lean construction management projects on a substantial scale. Similarly they have suggested a conceptual framework for policy convergence in adopting Kaizen in lean construction management projects. Despite their enthusiasm for the concept of Kaizen some modern researchers have expressed doubt about the efficacy of Kaizen in varied project management settings where stakeholders happened to have a sizeable interest in the project. For example Matthews and Howell (2005) argue that Integrated Project Delivery (IPD) model has much greater relevance in ensuring constant monitoring of the selection process of participants, project transparency and constant dialogue throughout the process. The authors’ belief that IPD model would solve most of the problems associated with the delivery phase is based on the fact that project administrators and managers as stakeholders would have the same degree of concern as shareholders have. However recent research findings suggest that empirical evidence is more centered on highly probable settings such as managers of production management processes have a tendency not to be transparent (Eccles et al. 2007). This behavioral tendency is in conformance with many research outcomes related to managers’ transparency and continuous engagement with other stakeholders. According to Ohno the supply chain management strategy at Toyota was highly successful due to the foresight of the top management. Toyota’s System was characterized by a desire to complete against rivals who were increasingly becoming more knowledgeable about growing markets and changing customer attitudes. On the other hand in lean construction and related project management such rivalry is not so much emphasized. What id emphasized is the reduction of costs, satisfaction of the customer and improvement of the quality. These three objectives are regarded as end purposes that are conclusive and not relative. In other words it is the delivery process that matters in the management of a production system in lean construction. Project deliverables are defined and exclusively and conclusively treated as such. Thus the outcomes related to the management of the system are defined subject to some limiting criteria. In the IPD model these limitations are sought to be overcome though yet again the extent to which it is practicable is not known. For instance the IPD model does not have a well developed convergence simulator. Therefore it is not possible to simulate the level of convergence and/or divergence that actually obtains in a practical setting. The production system of the project management phase cannot be determined with a degree of accuracy in the absence of such defining criteria. Next the Last Planner System (LPS) is intended to bring about an improvement in the designing and building program predictability phase. In other words the LPS is intended to improve the delivery phase of the project so that the client is satisfied. The system combines a number of features of the project delivery phase to achieve a synthesis of elements. While the LPS promises a maximum amount of benefits to the client, there is a question mark over its supplier engagement policy (Ridley, 2008). In the first instance supply chain management process is highly characterized by uncertainties. Therefore any predictability of outcomes associated with programs can be regarded as unwieldy. Collaborative programming under LPS is also subject to other failures such as the managers inability to engage suppliers on par with their respective influences within the supply chain process. Some suppliers of critically important components and materials to the project might enjoy much greater influence over the delivery phase than others thus leading to program uncertainty. The LPS however has some benefits associated with the organizational setting. For example project delivery can be improved when supplier networks are required to act in conformance with pre scheduled programs in collaboration with the rest of the staff. Assuming that such collaborative efforts are limited only to the program management level, there can still be an extension of the physical environmental coordination effort to include individual supplier level integration so that the degree of predictability would increase with regard to delivery schedule. The LPS also has a distinct advantage in rescheduling the work week by removing duplicate task from the program so that the critical path is shorten to achieve some of the main objectives predicted under lean construction projects. The reduction of the number of work weeks to a minimum possible enables a set of new parameters to be introduced in to the existing contingency models. In other words as an when the degree of divergence is brought down the level of convergence increases in conformance with scheduling criteria of the project management process. Supporters of the LPS argue that a systemic reduction in the number of work weeks in the total program would essentially entail some cost related benefits as well. For example they argue that costs can be minimized by removing the unnecessary work weeks from the total project so that the customer would be happy to take the delivery of the project ahead of the schedule. One of the elements in the LPS is the adoption of the Percentage of Promises Completed (PPC) to measure the success of the LPS. However the PPC in itself can be subject to chaotic variance at each stage of project evolution. Form the design phase up until the delivery phase the project life cycle would have to face unexpected uncertainties. Thus the measurement of its success depends on the value of the probability of divergence or variance. As a result there is very little agreement on the learning outcomes between the LPS related success and the realistic outcomes of the successful management of the project’s production life cycle. The current literature amply supports this argument by pointing out to the existence of the following three learning outcomes. Independent researchers have pointed out to the existence of an error term roughly equal to plus or minus two in value in respect of divergence. Empirical evidence shows that the LPS has acquired an additional dimension in project management literature due to its emphasis on increasing the collaborative efforts of supplier networks. However as already pointed out the degree of the individual supplier’s influence within the network is ignored. The LPS has more or less been welcome among project managers who are inclined to believe in the power of suppliers as against customers and shareholders. Finally some researchers have identified the existence of a promise cycle identical in nature to the life cycle in project production management. The lean construction sphere has always been concerned with cost management, quality improvement and delivery related constraints. The promise cycle is based on minimizing delay through efficient management of the work schedule. However as with any other model the promise cycle too has some drawbacks. For instance its emphasis on the delivery phase compromises other phases such as quality improvement and transparency. Therefore this literature review comes to the conclusion that starting from highly theoretical approaches in the early 1990’s up to this moment lean construction has come through a labyrinthine of ups and downs. However its current literature suggests that there is more promise than dejection in the coming years in lean construction. REFERENCES 1. Day, A 2008, How to get Research Published in Journals, Gower, Aldershot. 2. Eccles, T, Sayce, S & Plimmer, S 2007, Property & Construction Economics, Cengage Learning Business Press, Florence. 3. Ridley, D 2008, The Literature Review: a step-by-step guide for students, Sage, London. 4. Gleeson, F & Townend, J 2007, Lean construction in the corporate world of the U.K. construction industry, University of Manchester, Manchester. 5. Koskela, L 1992, ‘Application of the New Production Philosophy to Construction’, Technical Report 72, Stanford University, California. 6. Abdelhamid, 2007, Lean Construction Principles, Michigan State University, Michigan. 7. Ballard, G 1994, The Last Planner, Northern California Construction Institute Spring Conference, California. 8. Ballard, G, & Howell, GA 2003, Competing Construction Management Paradigms, Proceedings of the 2003 ASCE Construction Research Congress, Hawaii. 9. Salem, O, Solomon, J, Genaidy, A & Luegring, M 2005, ‘Site Implementation and Assessment of Lean Construction Techniques’, Lean Construction Journal, vol. 2, no. 2, pp. 1–21. 10. Mastroianni, R & Abdelhamid, TS 2003, ‘The Challenge: The Impetus For Change To Lean Project Delivery’, Proceedings of the 11th Annual Conference for Lean Construction, Virginia. 11. Abdelhamid, T S 2004, ‘The Self-Destruction and Renewal of LEAN CONSTRUCTION Theory: A Prediction from Boyd’s Theory’. Proceedings of the 12th Annual Conference of the International Group for Lean Construction, Denmark. Read More