Real-time and dynamic schedule optimization of construction projects on the basis of lean construction

Lean construction has been newly applied to construction industry. The best performance of a project can be achieved through the precise definition of construction product, rational work break structure, lean supply chain, decrease of resources waste, objective control and so forth. Referring to the characteristics of schedule planning of construction projects and lean construction philosophy, we proposed optimizing methodology of real-time and dynamic schedule of construction projects based on lean construction. The basis of the methodology is process reorganization and lean supply in construction enterprises. The traditional estimating method of the activity duration is fuzzy and random;however, a newly proposed lean forecasting method employs multi-components linear-regression, back-propagation artificial neural networks and learning curve. Taking account of the limited resources and the fixed duration of a project, the optimizing method of the real-time and dynamic schedule adopts the concept of resource driving. To optimize the schedule of a construction project timely and effectively, an intellectualized schedule management system was developed. It can work out the initial schedule, optimize the real-time and dynamic schedule, and display the schedule with the Gant Chart, the net-work graph and the space-time line chart. A case study was also presented to explain the proposed method.

Lean Construction in Supply Chain Management： Supplier and Buyer Relationship in Social Housing

To the accomplishment of this article, we have chosen, as a case study, a small Goiana construction company that acted in the market of social housing. The main goal of this work is to analyze the fundamental aspects related to the management of the flow of supplies in civil construction to achieve a greater streamlining of logistic processes involved in supplying material. A checklist was developed for the purpose of data collection, and it was applied by means of an interview with the person in charge of the purchase department of the enterprise. In addition, this person is the engineer of the site. Taking into account the exploratory feature of this research, the construction site was visited so that some issues, such as quality aspects, losses, cleanliness and organization, could be observed. This on-site data collection visit was carried out through visual analyses and photographs. The obtained results were subdivided into a quantitative and a qualitative analysis. In this way, it was possible to see that the production process still has many phases to be improved. What is more, it was possible to see that the construction company knows its flaws and necessities to improve its processes although the final result does not have the expected quality. Being aware of this need for improvement, the construction company aims at having an affordable price product to the target public, especially when it is associated to an image that shows quality.

A Study of Challenges and Benefits of Lean Construction(LC)Principles in Omani Construction Industry

There are frequent failures in the project delivery in time and increasing the waste in Oman construction industry.Lean Construction(LC)principles which are lean thinking in design and construction process may be a possible solution.Hence,the paper is aimed on exploring the status of the LC practices and its impact on Omani Construction Industry(OCI).The paper presents barriers,potential benefits,and the measures of suitability and acceptability of LC principles.A quantitative research approach was adopted and research data was collected using an online questionnaire survey in Oman.The data were analysed and results are presented in tables and charts followed by critical discussions.The survey found that onethird of the construction professionals have a good awareness and half of them having a higher level awareness about LC practices.More than one third of the construction organisations are adopting LC principles with a high consensus on the suitability and acceptability,and they recognised that time commitment is necessary for the successful implementation and achieve benefits.The study concludes that the reduction in project delivery time and construction at site waste is the key advantage of implementing LC priciples in design and construction stages in the omani construction industry.

分析Lean Construction在工程质量管理中的运用

社会的发展使得建设工程数量不断增多,在工程建设过程中可能出现的质量问题也在不断增多,对于这些问题依靠以往的质量管理方法很难从根本上改善工程质量。文章结合工程质量管理实际情况提出Lean Construction(精益建设)这一思想理念,旨在借助精益建设来更好的提升工程质量。

SUSTAINABLE VALUE ON CONSTRUCTION PROJECTS AND LEAN CONSTRUCTION

Lean production is a systemic approach to meeting customer expectations, whatever they value, by reducing waste.At fi rst glance, lean then could only contribute to sustainability, while sustainability is achieved only if the customervalues sustainability. The paper has two objectives. One is to examine whether sustainability is feasible using leanproduction with sustainability as an added value. The second objective is to examine how current lean constructiontools and methods impact the construction and operation of sustainable facilities. The authors also suggest how theselean construction tools and methods have evolved to contribute to green construction. For this study, the authorsinterviewed lean adopters and conducted literature surveys on lean principles and methods, and its impacts on theeconomic, social and environmental sustainability.

4D Design and Simulation Technologies and Process Design Patterns to Support Lean Construction Methods

The objective of this ongoing joint research program is to determine how 3D/4D modeling, simulation and visualization of Products (buildings), Organizations and Processes (POP) can support lean construction. Initial findings suggest that Process Design Pattern may have the potential to intuitively support ICT based lean construction. We initiated a 'Process Archeology' in order to reveal the requirements for tools that can support the planning, simulation and control of lean construction methods. First findings show that existing tools provide only limited support and therefore, we started to develop new methodologies and technologies to overcome these shortcomings. Through the introduction of Process Design Patterns, we intent to establish process thinking in the interdisciplinary POP design. Optimized construction processes may be synthesized with semi-automatic methods by applying Process Design Patterns on building structures. By providing process templates that integrate problem solution and expert knowledge, Process Design Patterns may have the potential to ensure high quality process models.

Owner-dominated building information modeling and lean construction in a megaproject

The integration of building information modeling(BIM)and lean construction(LC)provides a solution for the management of megaprojects.Previous studies have generally focused on the theoretical or empirical adoption of BIM and LC.Moreover,only a few studies have examined the approach of simultaneously using BIM and LC in megaprojects.Therefore,an intensive study on the application of BIM and LC in megaprojects,particularly to explore considerably effective integrated application modes of BIM and LC in megaprojects,will substantially promote the management efficiency of megaprojects.The current study describes a method that integrates owner-dominated BIM and LC that was developed in a case study.The proposed method provides a framework for all stakeholders to use BIM and LC in a megaproject dominated by the owner.The interactional relations among the owner,BIM,and LC were analyzed and positive interactions were identified.These positive interactions served as a basis for the implementation of this integrated approach in a case study and could be applied to other megaprojects.The megaproject(i.e.,airport construction project)was examined to verify the performance of the developed method.Results showed that the integration of BIM and LC dominated by the owner can improve management performance and achieve high quality standard.

Proposing a development framework for sustainable architecture, engineering, and construction industry in China: Challenges, best practice, and future directions

China’s architecture,engineering,and construction(AEC)industry needs a clear and sustainable development roadmap.Drawing inspiration from speeches delivered at a seminar hosted by the Chinese Academy of Engineering and extensive literature research on Chinese policies,this article presents a summary of the current trends in the AEC industry in four dimensions:industrialization as the foundation,intelligence as the enabler,lean management as the strategy,and green development as the goal.These four dimensions are intricately interconnected and rooted in multiple disciplines.The article provides a detailed review of the current practices,challenges,and future directions associated with each dimension.Additionally,ten grand challenges were proposed to stimulate discussions on the future of the AEC industry.This article offers an overarching understanding of the AEC industry and presents a four-dimension framework for sustainable development,which can be valuable for AEC practitioners.

PHOENIX’S FIRST NET-ZERO ENERGY OFFICE RETROFIT: A GREEN AND LEAN CASE STUDY

Many in the construction industry view lean practices as a means for reducing cost and schedule while maintaining or improving quality. This paper argues that lean practices can also be used to promote energy savings throughout a building’s life cycle. This paper presents a case study of an existing building retrofit in Phoenix, Arizona. The project owner, a general contractor, self-performed much of the building construction and worked to ensure the project team aligned around the project’s net-zero energy goal. All building systems, excepting the walls and roof, were re-designed and re-constructed. After retrofit, the building has achieved net-zero energy consumption;that is, the building produces as much energy as it consumes on an annual basis. Deep building energy retrofits typically result in larger energy savings than operational changes alone can provide, as these retrofits take a whole-building approach to design (i.e., optimize the whole) and implement integrated project delivery methods (e.g., (AIA, 2007)). This paper discusses a net-zero energy retrofit and how lessons learned on this project could apply to other deep energy retrofits for commercial buildings (where “deep” refers to energy savings of 25% or more) that may significantly improve building value (Miller and Pogue, 2009). The inefficiency of existing building stock supports the need for retrofitting: energy consumption in the existing building stock in the United States accounts for approximately 41% of the total primary energy consumption (US DOE, 2012). In order to reduce this consumption, existing buildings must be retrofit, through replacement or upgrade of their existing building systems, to improve their energy performance. Beyond the energy motivation, a building’s operating costs account for the largest portion of the life cycle cost. Thus, deep energy retrofit projects offer an opportunity to significantly reduce both national energy consumption and expenditures. While much research exists on the topic of energy retrofits, very little explores the role of the contractor. This paper explores the contractor’s role (rather than the designer’s or engineer’s role) in delivering deep energy retrofit projects. The contractor plays a critical role in delivering a project that meets the owner’s expectations and goals and satisfies the specifications (Ahn and Pearce, 2007). Namely, the contractor executes the plans and specifications, giving physical reality to the design team’s vision. In the case of deep energy retrofits, this role is particularly important, as installation and operation must conform to the design intent to achieve the predicted energy performance. Moreover, the contractor must understand the existing condition to effectively retrofit the building. This paper explores critical building energy efficiency measures and processes for achieving deep energy savings in retrofit projects. Specifically, we present the role of the contractor in a case study project in Phoenix, Arizona where the contractor was engaged in the project early in the design stage. This paper discusses the process of developing and selecting energy efficiency measures (EEMs). It explains the reasons for choosing particular EEMs, including a discussion of selecting an appropriate baseline for energy savings calculations, and documents the impact of EEMs on total energy consumption and design intent. The paper concludes with a discussion of recommendations that, if applied in part or whole, will increase the effectiveness of future construction teams in delivering deep energy retrofit projects.

Requirements in performance measurement systems of construction projects from the lean production perspective

Performance measurement(PM)generates useful data for process control,facilitates communication between different sectors,and helps to align efforts on the most important aspects of the business.Thus,PM plays a key role in the management of projects and organizations.PM is also important in the implementation of lean production principles and methods,such as reducing the share of nonvalue-adding activities,increasing process transparency,building continuous improvement into the process,and benchmarking.Moreover,the adoption of the lean production philosophy requires changes in PM.Despite its importance,limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects.In addition,studies on how lean companies(or projects)use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited.This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems.Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems.The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.

Investigating the challenges related to combining BIM and Last Planner System on construction sites

The construction industry is facing a gradual but important transformation toward more productivity and collaboration.In this framework,two major approaches are often cited in the literature as having the potential to improve the practices in the industry:Building Information Modeling(BIM)and Lean Construction.Several scientific studies have demonstrated the synergy of these two approaches and very recent research has reported positive results from the use of software applications as support for their implementation on construction sites.However,the stakes of such integration have been very little studied.This article presents the results of a research project conducted within a general contractor firm that decided to implement BIM and Last Planner System(LPS)on its construction sites.The research uses a four-stage action research approach,including the characterization of the research issue,the establishment of an action plan,its implementation and its evaluation.Compared to recent related studies,the research is less enthusiastic.While it highlights the need for new tools to improve production planning and control,it also points to a strong resistance to change by practitioners at the site.They emphasize the necessity for adequate pre-service training and the need for new resources that can work flill-time on the ongoing training of site teams.In addition,some limitations of the tool lead workers to believe that it can quickly become a factor that slows down their daily work rather than improving it.Based on the advice of professionals,the paper formulates some recommendations to the industry,the researchers and the software developers.

Efficient logistics enabled by smart solutions in tunneling

While logistics comprises an important part of tunneling costs,it is generally not considered a lever of performance but rather a con-straint to a project’s progress.This study presents some insights on how smart technology can impact the tunneling industry.The impact is even greater because of the complexity of the tunneling supply chain,and smart technology could help support this process.Finally,we discuss how the nature of the tunneling industry invites stakeholders to develop a common understanding of the project prior to con-struction to successfully deploy smart technology during the use or maintenance phase.

Last Planner System and Scrum: Comparative analysis and suggestions for adjustments

This study provides a critical review of the concepts of Agile,Lean,Scrum,and Last Planner®System(LPS).A comparative analysis is conducted between LPS and Scrum to expand LPS by considering Scrum’s best practices.Eight dimensions,namely,1)origins,2)main purpose,3)overall system/framework process,4)tools or artifacts maintained by the team,5)team composition and main roles,6)regular events or team meetings,7)metrics/dashboards,and 8)approach to learning,are evaluated.After analyzing side by side the eight dimensions,it was found that many aspects from Scrum already exist in LPS in the same or similar form.However,the authors identify four main elements from Scrum that can be leveraged to improve the LPS benchmark,such as considering the Scrum“Increment”concept into LPS,having a clear definition of roles and responsibilities,or adding an equivalent to a Scrum Master to have a designated"rule keeper”in LPS.These opportunities to be considered in new LPS benchmarks need to be tested and validated with real applications.To the best of the authors5 knowledge,this work is the first to comprehensively compare Scrum(Agile)and LPS(Lean)and could be seen as a contribution toward the evolution of the Last Planner System for the academic and industrial environments.