1、 CHANGCHUN INSTITUTE OF TECHNOLOGY Learning to see the Effects of Improved Workflowin Civil Engineering Projects 学会发现 改善土木工程项目工作流程的影响 资料来源： Lean Construction Journal 设计题目： 长春市热电厂办公楼结构、施工设计 学生姓名： 宗翔宇 学院名称： 土木学院 专业名称： 土木 工程专业 班级名称： 土木 0942 学 号： 0905411242 指导教师： 沙 勇 教师职称： 讲 师 完成时间： 2013/3/26 2013 年 03
2、月 26 日 1 “Learning to see” the Effects of Improved Workflow in Civil Engineering Projects Peter Simonsson1, Anders Bjornfot 2, Jarkko Erikshammar 3 & still OlofssonThomas4 Understanding & improving workflow A flow is composed of transformations, inspections, moving and waiting (Koskela, 2000). Accor
3、ding to Womack and Jones (2003), workflow refers to the movement of materials, information and resources through a system. To create a smooth flow of work, the availability of materials, information and resources must be controlled during the whole production process (Thomas et al, 2003). Reducing o
4、n-site material handling and lead times through proper workflow management is an important part of the construction industrys improvement of productivity (Ballard et al., 2003). According to Formoso et al. (2002), waste elimination is a focus for workflow improvement within Lean production. Womack a
5、nd Jones (2003) defines waste as any human activity that absorbs resources without creating any value, i.e. waiting time, over production, unnecessary inventory, erroneous processes, unnecessary movement and transports, products with errors, and not meeting customer demands. Koskela (2000) identifie
6、d construction waste as poor/incorrect quality of the product, rework, excessive and left over materials, material handling, materials in stock, and work in suboptimal conditions. Mossman (2009) argued that waste should be defined in relation to value, i.e. waste elimination through value creation.
7、It should be noted, that an over-emphasis on waste reduction can become counterproductive as low inventory, or a lack of production capacity, can lead to supply chain disruptions. Improving the flow of work The most readily applicable method for improving workflow is pull production. Pull means that
8、 no upstream actor should produce anything until the customer downstream asks for it (Womack and 2 Jones,2003). In construction, the most recognized and applied tool to generate pull is the Last Planner system of production control. However, there are ertainly other attempts at establishing pull in
9、on-site construction of which Line-of-Balance (Seppnen et al., 2010) and pull production of multi-storey housing (Sacks and Goldin, 2007； Sacks et al., 2009) are but two examples. Another approach to minimize wasteful activities is to standardize work tasks. The execution of work tasks varies from c
10、onstruction site to construction site and from worker to worker (Nakagawa, 2005). Work is standardized to systemize operations and materials so that human motion between operations and needed resources is used in the best known order and hence most efficiently. Through process standardization, the m
11、anufacturing process becomes more robust, leading to operational excellence, continuous improvement and elimination of non-value-adding activities (lvarez et al., 2009).Achieving the right flow of work in production processes is important. Decisions made early affects how, e.g. a bridge is to be bui
12、lt and hence affects the workflow on-site. Such factors as location, type and shape, material choice and detail design all affect the flow of work (Ray et al., 1996； Lam et al., 2006； Jergeas and Van Der Put, 2001). Hence, to achieve workflow at the construction site, the design and planning phase n
13、eeds to be controlled and managed from a buildability perspective. Adams (1989) stated that the key to success is the early design stage where knowledge from all vital actors is gathered to create buildability for a specific project. Wong et al. (2004) states that design decisions affect how a build
14、ing is to be built and determine the types as well as level of resources to be involved in the conversion process, and that designers often lack the knowledge and the incentive to make the right decisions. Consequently, it is possible to work with workflow at both the early stages of a construction
15、project using so called proactive workflow methods and during the project execution at the construction site using so called reactive workflow methods (Figure 1): Proactive workflow management. Aims at removing hindrances to production workflow in the design phase. Common methods are e.g. improved b
16、uildability and proper production planning. Another useful method for proactive workflow management is simulation using for example 4D planning . Reactive workflow management. Aims at removing hindrances in the production phase so that even workflow is achieve at the construction site. Common methods are e.g. planning for pull production and
