Lean Construction as it Relates to Construction Safety A Brief Introduction Presented by Charles Rountree & Bolivar Senior At the November 9, 2011, Associated Builders and Contractors Safety Committee Meeting
Abstract By the end of this presentation participants should be able to: • Understand some key definitions, principles and methods of Lean Construction, • Recognize how Lean Construction principles and methods apply to construction safety, • And start practicing Lean Construction safety principles and methods to improve safety on their projects.
Abstract This presentation will explore the following four sections: (Thanks to Somik Ghosh & Deborah Young-Corbett, in which their 2009 white paper, Intersection Between Lean Construction and Safety Research: A Review of the Literature, served as the basis for this presentation) • Current State of Construction Safety • Lean Construction • Safety & Lean Construction • Conclusion
Abstract Two key words to define: System and Safety What is a system? (definition from Wikipedia) • “is a set of interacting or interdependent components, forming an integrated whole.”
Abstract What is Safety? • Safety is a system property that emerges from a conglomerate of components, subsystems, software, organizations, human behavior, and their interactions. • Over the last 20-30 years the accumulation of major mishaps and case studies have made it clear that organizations must revise their handling of processes and capabilities to address not only technical but also human and organizational risk factors. Numerous strategic case studies and accident analyses have pointed to the need to monitor and manage risk continuously throughout the life cycle of a system, and in particular to find ways of maintain a balance between safety and the often considerable pressures to meet production and efficiency goals (just think of NASA). • Safety is something a system does, rather than something a system has. This means that we must try to understand how a system can actively ensure that things do not get out of hand and that control is not lost. Systems should be made resilient, rather than reliable. It is not enough that they are reliable so that the failure probability is acceptably low; they must also be resilient and have the ability to recover from irregular variations, disruptions and a degradation of expected working conditions.
Current State of Construction Safety Why should we talk about improving safety in the construction industry? • Enlightened clients & OSHA demand excellent safety performance from contractors/builders. • Clients & contractors/builders search for more economic benefits with projects. • Economic pressures on construction firms to increase productivity, which can lead to increased exposure to new risks, such as increased accident and injury rates. • Coupled with the organizational pressure for productivity, the individual motivation of the workers to minimize safety effort, push them to the brink of a loss of control work zone. • Furthermore, the dynamic, complex, and often unpredictable construction tasks and environment add to the risks. Thus, improving safety in construction remains a priority in almost every country around the world, because the construction industry stands out among all other industries as the main contributor to severe and fatal accidents.
Current State of Construction Safety Safety matters! A 2005, Center to Protect Workers’ Rights report states, that the fatality rate in construction industry accounts for an annual total in excess of 1,000, which is more than three times the fatality rate of the manufacturing sector. The report also states that there are more than 182,000 serious injuries annually in construction. 31a. Rate of deaths from injuries in construction, selected countries, 2005
Current State of Construction Safety • The loss or injury of workers, and the resulting disruption to progress of work, represents waste in the performance of construction. • Left uncontrolled, these factors can create disruption, due to many cost related factors; such as escalating workers’ compensation insurance costs, high cost of medical treatment and rehabilitation program. • The economic losses also include indirect losses such as administrative cost, productivity losses and low morale.
Current State of Construction Safety • The Occupational Safety and Health Administration requires companies to observe a wealth of rules and regulations designed to keep workers safe and healthy in their workplaces. • Fines can be hefty if the federal agency catches a manufacturing company not complying with those regulations, and severe consequences are assured -- to both the manufacturer and employee -- if failure to comply with the regulations leads to grievous injuries or even death.
Current State of Construction Safety • Nevertheless, safety should not only be about compliance. • Safety should also be about building a culture that engages the entire workforce in improving workplace safety. However, too often the safety role is put in the hands of one person (human resources manager or EHS director, for example) to push down to the employees. • We have to have compliance, but you can also have a lean construction continuous improvement component.
Current State of Construction Safety These are some of the most common best practices that construction companies use to improve safety outcomes: • Training in safety requirements, safe use of tools, equipment operation, etc. • Toolbox talks reviewing tool use, and project hazards. • Pre-task hazard planning • Inspections by safety and project management personnel. • Safety performance incentives that reward for individuals or project teams. • A citation program to recognize both good and bad behavior. • Drug and alcohol screening • Use of protective equipment to reduce the consequences of incidents.
Current State of Construction Safety • The effectiveness of these strategies to prevent accidents is limited! • Why? • Because educational and motivational pressure to work safely is always at odds with the organizational imperative to increase productivity and the individual’s urge to expend less effort. • As a result, workers will often be working near the edge, where errors or normal variation in performance may cause workers to lose control. While errors will always occur in complex and dynamic situations, the consequences of errors increases, as workers move closer to the boundary of safe performance. Dire consequences follow when workers approach the edge where even a minor error can lead to loss of control.
Lean Construction What is Lean Construction? (From Wikipedia) • Lean Construction is a combination of original research and development in design and construction with an adaption of lean manufacturing principles and practices to the end-to-end design and construction process. • Unlike manufacturing, construction is a project based-production process. Lean construction is concerned with the 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). • This approach tries to manage and improve construction processes with minimum cost and maximum value by considering customer needs. (Koskela et al. 2002)
Lean Construction According to the Lean Construction Institute (LCI) website, Lean Construction is a production management-based approach to project delivery – a new way to design and build capital facilities. Lean production management has caused a revolution in manufacturing design, supply and assembly. Applied to construction, Lean changes the way work is done throughout the delivery process. Lean Construction extends from the objectives of a lean production system – maximize value and minimize waste - to specific techniques and applies them in a new project delivery process. As a result: • The facility and its delivery process are designed together to better reveal and support customer purposes. Positive iteration within the process is supported and negative iteration reduced. • Work is structured throughout the process to maximize value and to reduce waste at the project delivery level. • Efforts to manage and improve performance are aimed at improving total project performance because it is more important than reducing the cost or increasing the speed of any activity. • "Control" is redefined from "monitoring results" to "making things happen." The performance of the planning and control systems are measured and improved. The reliable release of work between specialists in design, supply and assembly assures value is delivered to the customer and waste is reduced. Lean Construction is particularly useful on complex, uncertain and quick projects.
Lean Construction • 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).” • Designing a production system to achieve the stated ends is only possible through the collaboration of all project participants (Owner, A/E, Constructors, Facility Managers, End-user) at early stages of the project. • This goes beyond the contractual arrangement of design/build or constructability reviews where constructors, and sometime facility managers, merely react to designs instead of informing and influencing the design (Abdelhamid et al. 2008).
Lean Construction Historical Development • In 1992, Laura Koskela expressed the need for a new management theory in construction. He put forth the transformation, flow and value (TFV) theory of production management t oovercome the shortcomings in existing planning, execution, and control paradigms as advocated by contemporary project management theory. See the figure posted on the next slide. • Another paradigm-breaking anomaly was that observed by Ballard (1994), Ballard and Howell (1994a and 1994b), Howell and Ballard (1994a 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).
Lean Construction Possible future of lean construction
Lean Construction A new project management common sense Optimizing the project, not the piece.
Lean Construction • Current construction project delivery practices fail to provide a solid basis for improvement and are inadequate when projects are complex, uncertain and quick. • Meanwhile the manufacturing industry has experienced significance performance increases. • The Lean Construction Institute aims to extend to the construction industry the Lean Revolution that was started in manufacturing, most notably Toyota. This approach maximizes the value delivered to the customer while minimizing waste.
Safety and Lean Construction • Since the initiation by Koskela in 1992, researchers working closely with practitioners have been investigating the theory, principles, and techniques of Lean Construction and Lean Construction as it relates to construction safety. These efforts cover a wide range of topics and the International Group for Lean Construction (IGLC) has become a platform to showcase all these research efforts. • Four themes emerge for approaches to safety and lean construction: 1) a new approach to construction safety, 2) performance measurement of safety, 3) forecasting risk levels, and 4) safety through production planning.
1. New approach to construction safety • The rate of injuries and fatalities in the construction industry has forced researchers and practitioners to look for new approaches for construction safety. Attempts have been made to introduce behavior-based safety approaches for construction projects. • Salem et al. provided a decision support system to assist construction companies (especially small and medium sized) in implementing behavior based safety. Although behavior-based safety has been widely accepted in other industries, it cannot be exactly replicated in the construction industry and it also involves a huge amount of money to implement full fledged behavior based safety. • Another approach of identifying contributing factors of accidents, other than human errors and machine malfunction, is to look into organizational factors through resilience engineering. Resilience engineering emphasizes how organizations manage unexpected events and how people in these organizations become prepared to cope with unplanned and unforeseen events.
1.1 Cognitive systems engineering approach • Thus far, most efforts to understand the accident process have failed to recognize the dynamic and dependent nature of construction work. • Rasmussen’s model of ‘migration to accidents’ and Howell’s model of ‘three zones of safety’ within the paradigm of cognitive systems engineering offers a broader and more powerful view of the relationship between individual and work environment, and of the factors that lead to incidents. • In this model as shown in Figures 1 and 2, laborers work away from the organization’s boundary of economic failure and individual’s boundary of excessive effort. Accidents occur when workers migrate towards the boundary of functionally acceptable behavior and lose control. • ‘Migration to accidents’ model contradicts current practices by recognizing that both individual tendencies and organizational factors push people to work in risky circumstances. The ideas of Rasmussen and Howell have been advocated both in construction as well as in other industries as an effective basis for designing adaptive work systems that take into account the inevitable migration of workers towards the boundary of loss of control.
1.1 Cognitive systems engineering approach Figure 2: The migration of work toward loss of control. (Rasmussen 1994)
Cognitive systems engineering approach Figure 2: Three Zones of Risk. (Howell 2001)
2. Performance measurement for safety • Increasing safety is critical in the context of improving productivity and efficiency in construction industry. Thus, the development of valid safety performance metrics is an important first step towards improving safety. • Unfortunately, most conventional metrics of safety performance deals with rates of accident or incident occurrence. This type of metric has inherent limitations: it is reactive in nature, causal relationships cannot be established, and it does not include positive aspects of safety performance. Development and implementation of safety-related performance measures within the lean construction paradigm can be classified into two broad categories. The first is related to safety process improvement and other at the detailed operational level. • The study by Marosszeky et al. employed an iterative process analysis: identifying potential performance measures, prioritizing and selecting measures, and finally the development of key performance indicators and the feedback mechanism.
3. Forecasting safety risk levels • It has been stated that a proactive safety policy is a more efficient way of managing safety in order to prevent accidents than a reactive policy. Sacks et al. presents a conceptually advanced model to support proactive safety management. The authors argue that most common factors that have a substantial influence on most construction projects are time dependent such as human factors, physical hazards, environmental factors, etc. • Thus, knowing the level of risk as it changes with time would help in identifying high risk construction activities and allocate precautions accordingly. The model put forth by Sacks et al. enables forecasting risk levels for teams as well as individual workers as a function of time. This time dependent model can be used to implement management strategies that focus efforts where needed and reduce efforts where it is wasted, in contrast to safety activities that are planned with constant effort.
4. Safety through production planning Bolivar’s turn.
Conclusion • This presentation summarizes the current state of construction safety. • It also explored introductory principles and methods associated with lean construction. • We reviewed four main lean construction approaches to construction safety: 1) production planning and control, 2) performance measures to improve safety, 3) forecasting risk levels as a function of time and 4) developing new approaches to construction safety. • Considering the stage of plateau, that safety in construction industry has reached using the OSHA compliance in and of itself, best practices, which one or all of these lean construction safety approaches will you try implementing?