8,040 research outputs found

    Tracking the built status of MEP works: Assessing the value of a Scan-vs-BIM system

    Get PDF

    Tracking of secondary and temporary objects in structural concrete work

    Get PDF
    Previous research has shown that “Scan-vs-BIM ” object recognition systems, that fuse 3D point clouds from Terrestrial Laser Scanning (TLS) or digital photogrammetry with 4D project BIM, provide valuable information for tracking structural works. However, until now, the potential of these systems has been demonstrated for tracking progress of permanent structures only; no work has been reported yet on tracking secondary or temporary structures. For structural concrete work, temporary structures include formwork, scaffolding and shoring, while secondary components include rebar. Together, they constitute most of the earned value in concrete work. The impact of tracking such elements would thus be added veracity and detail to earned value calculations, and subsequently better project control and performance. This paper presents three different techniques for recognizing concrete construction secondary and temporary objects in TLS point clouds. Two of the techniques are tested using real-life data collected from a reinforced concrete building construction site. The preliminary experimental results show that it is feasible to recognize secondary and temporary objects in TLS point clouds with good accuracy; but it is envisaged that superior results could be achieved by using additional cues such colour and 3D edge information

    Earned Schedule min-max: Two new EVM metrics for monitoring and controlling projects

    Full text link
    [EN] Earned Value Management (EVM) is a well-known project management technique for monitoring project pro-gress. Over the last 15 years, many promising EVM metrics have been proposed to get, among other improve-ments, better actual project duration and cost estimates. Papers comparing the performance of all these metricsare, however, scarce and sometimes contradictory.In this paper, a simulation and empirical comparison of 26 deterministic project duration forecasting tech-niques under the EVM framework is developed. Among them, two new metrics: Earned Schedule min (ESmin) andEarned Schedule max (ESmax) are proposed.ESminandESmaxoffer a new and simpler activity-level calculationapproach of the traditional Earned Schedule metric. Top performing (most accurate) metrics: Earned Schedule(ES), Earned Duration (ED) and Effective Earned Schedule (ES(e)) with Performance Factor 1 (PF= 1), areslightly outperformed by the new metrics which also offer some interesting applications for enhanced projectcontrol.The first author acknowledges the Spanish Ministry of Science, Innovation and Universities for his Ramon y Cajal contract (RYC-2017-22222) co -funded by the European Social Fund. This work was also supported by the second author's "Estancias de movilidad en el extranjero Jose Castillejo para jovenes doctores, 2017 (grant ref. CAS17/00488)" and the fourth author's "Estancias de profesores e investigadores senior en centros extranjeros, incluido el programa "Salvador de Madariaga" 2018 (grant ref. PRX18/00381)", both also from the Spanish Ministry of Science, Innovation and UniversitiesBallesteros Pérez, P.; Sanz-Ablanedo, E.; Mora-Melià, D.; González-Cruz, M.; Fuentes Bargues, JL.; Pellicer, E. (2019). Earned Schedule min-max: Two new EVM metrics for monitoring and controlling projects. Automation in Construction. 103:279-290. https://doi.org/10.1016/j.autcon.2019.03.016S27929010

    Stability and accuracy of deterministic project duration forecasting methods in earned value management

    Full text link
    [EN] Purpose Earned Value Management (EVM) is a project monitoring and control technique that enables the forecasting of a project's duration. Many EVM metrics and project duration forecasting methods have been proposed. However, very few studies have compared their accuracy and stability. Design/methodology/approach This paper presents an exhaustive stability and accuracy analysis of 27 deterministic EVM project duration forecasting methods. Stability is measured via Pearson's, Spearman's and Kendall's correlation coefficients while accuracy is measured by Mean Squared and Mean Absolute Percentage Errors. These parameters are determined at ten percentile intervals to track a given project's progress across 4,100 artificial project networks with varied topologies. Findings Findings support that stability and accuracy are inversely correlated for most forecasting methods, and also suggest that both significantly worsen as project networks become increasingly parallel. However, the AT + PD-ESmin forecasting method stands out as being the most accurate and reliable. Practical implications Implications of this study will allow construction project managers to resort to the simplest, most accurate and most stable EVM metrics when forecasting project duration. They will also be able to anticipate how the project topology (i.e., the network of activity predecessors) and the stage of project progress can condition their accuracy and stability. Originality/value Unlike previous research comparing EVM forecasting methods, this one includes all deterministic methods (classical and recent alike) and measures their performance in accordance with several parameters. Activity durations and costs are also modelled akin to those of construction projects.The first author acknowledges the University of Talca for his Doctoral Program Scholarship (RU-056-2019). The second author acknowledges the Spanish Ministry of Science and Innovation for his Ramon y Cajal contract (RYC-2017-22222) co-funded by the European Social Fund.Barrientos-Orellana, A.; Ballesteros-Pérez, P.; Mora-Melià, D.; González-Cruz, M.; Vanhoucke, M. (2022). Stability and accuracy of deterministic project duration forecasting methods in earned value management. Engineering, Construction and Architectural Management. 29(3):1449-1469. https://doi.org/10.1108/ECAM-12-2020-10451449146929

    Funding the Extraordinary: An Evaluation of The Kresge Foundation Arts and Culture Program's Institutional Capitalization Grantmaking

    Get PDF
    In undertaking an assessment of Kresge's Capitalization Program, NFF applied its own high-level framework to help answer Kresge's primary research questions and assess the progress of each grantee in meeting its stated capital targets. NFF has found that effective capitalization in the nonprofit sector requires attention to three key financial priorities: liquidity, adaptability and durability:1. Liquidity: Does the organization have adequate cash to meet its operating needs?2. Adaptability: Does the organization have flexible funds that allow it to make adjustments as circumstances change?3. Durability: Does the organization have sufficient resources to address the range of needs that it may face in future years?NFF's review of Kresge's grantees sought to assess capitalization by looking for evidence of organizational progress in building liquid funds for immediate operating needs, as well as longer-term balance sheet savings for adaptability and durability. NFF's evaluation of grantees involved a combination of data analysis and interviews
    • …
    corecore