Showing papers by "David Grau published in 2015"

Automated Tornado Damage Assessment and Wind Speed Estimation Based on Terrestrial Laser Scanning

Abstract: There are more than 1,000 tornadoes in the United States each year, yet engineers do not typically design for tornadoes because of insufficient information about wind loads. Collecting building-level damage data in the aftermath of tornadoes can improve the understanding of tornado winds, but these data are difficult to collect because of safety, time, and access constraints. This study presents and tests an automated geographic information system (GIS) method using postevent point cloud data collected by terrestrial scanners and preevent aerial images to calculate the percentage of roof and wall damage and estimate wind speeds at an individual building scale. Simulations determined that for typical point cloud density (>25 points/m2), a GIS raster cell size of 40–50 cm resulted in less than 10% error in damaged roof and wall detection. Data collected after recent tornadoes were used to correlate wind speed estimates and the percent of detected damage. The developed method estimated wind speeds f...

Predictability Index: Novel Metric to Assess Cost and Schedule Performance

Abstract: The ability to timely forecast accurate project outcomes is fundamental in an industry marked by endemic cost and schedule deviations. Indeed, owners and contractors alike make key strategic decisions about individual projects and capital investment programs alike based on forecasted values. As a departure from current cost and schedule assessments solely based on deviations at completion, this article introduces the Predictability Index, a novel performance metric that also considers the project team’s ability to timely predict outcomes at completion. This article conceptually explains and defines the index and, based on the statistical analysis of retrospective data from 135 completed projects, identifies threshold values of predictability performance. Complementary, lessons learned and observations collected from the adoption and assessment of predictability by industry organizations are also discussed. A significant cultural shift within an organization is necessary for project teams to focus ...

Impact of Real-time Project Control on Capital Project Cost and Schedule Performance

Abstract: This article assesses the combined influence of information integration and automated data analytics on project performance. To this end, retrospective data on 78 completed projects, with a total installed value of $8 billion, was collected. The level of internal and external information integration and automated analytics were used as surrogates of real-time project controls for statistical analyses purposes. Indeed, non-parametric statistical techniques were used to assess the impact of such technologies on cost and schedule performance. Overall, teams with a sophisticated degree of information integration and automated data analytics can control their projects with more reliable information and in a proactive manner so that informed decisions can be timely made on behalf of the project and the organization. DOI 10.5592/otmcj.2015.2.3 Research paper

A Call for New Research in the Lean Construction Community: Alternative Work Schedules

Abstract: While there is considerable research performed in the construction industry on the loss of productivity after a 5 day / 8 hour a day work week there is very little research exploring productivity with fewer work hours. Other industries have shown that they are more productive working shorter weekly schedules. Indeed, if we can produce a quality product with fewer resources, value stream is improved and a leaner process executed. More importantly, if we can be safer and improve quality of life we are achieving the most important tenant of lean, respect for people. To reinforce such notion, data shows that the US is 3% less productive than the other top 10 most productive countries in the world even though the US workforce works 21% more hours. Several countries, such as the Netherlands and Denmark, who work 29 and 33 hours per week, respectively, have a higher quality of life and have similar or higher productivity. This paper presents both a theoretical basis for alternative work schedules in construction as well as the results of a survey administered to trade contractor personnel, illustrating the potential safety benefits of a schedule change.

Stabilizing Craft Labor Workflow With Instantaneous Progress Reporting

Abstract: Stabilizing workflow is a common goal of research in lean construction, productivity, and production control methods. This study aimed to test the hypothesis that the combination of location-based work packaging and near real-time progress reporting contributes to reducing workflow variability. Some authors agree that daily monitoring allows timely actions to correct deviations from the baseline, which can increase workflow reliability. Thus, the objective of this study is to evaluate this statement in practice. The drywall installation in a healthcare facility served as the scenario for the test study. Drywall activities were divided into multiple tasks. Tasks were associated with locations and individually monitored. Although drywall tasks with unresolved constraints with mechanical activities did experience variations, a comprehensive analysis showed that most variations of workflow were proactively reduced.

Teaching engineering literacy to non-engineering students in formal learning environments

Abstract: Since enrollment rates in American college engineering programs have been constantly dropping, formal and informal processes to teach and learn engineering are on the rise. An opportunity actually exists to formally teach engineering to construction students in US colleges and universities. If non-engineers understand how science and technology work, they can better interact with scientists and engineers in the workforce and make informed decisions about when technology can be a solution to a problem, or when other solutions maybe more adequate. To this date, higher engineering education has been repeatedly investigated through the lenses of engineering programs and degrees. This paper investigates engineering literacy for non-engineering students, by comparing the performance of engineering and non-engineering students when gaining engineering literacy. The methodology of this study consists of analyzing the performance of construction management (CON) and civil and environmental engineering (CEE) students in comparable courses taught in both programs: introduction to geotechnical engineering and geotechnical applications. Data is collected over four distinct semesters. The results reveal that CON students scored significantly higher grades when the course was offered from a non-engineering perspective rather than from an engineering perspective. The results of the study highlight the need to develop clear and consistent teaching methods and techniques that take nonengineering students’ diverse backgrounds into consideration.