Papers by Thomas Olofsson
Proceedings of the ... ISARC, Jul 22, 2018
Industrialized house-builders are moving towards an enhanced production where management of infor... more Industrialized house-builders are moving towards an enhanced production where management of information along the value chain is critical in order to deliver housing projects on time and with the desired quality. Today digital tools and systems are used in both design and production to produce, deliver and instruct actors throughout the phases of a project. However, the information usually exists in different islands and manual transfers are required to keep the flow of information between IT-systems and individuals continuous. A key to improving the ability for the members in different stages of a project to work with the same information is to facilitate different views. One of the building blocks for creating bridges between the islands of information is to introduce bills of materials which can be used to organize information for different purposes. Uniting the use of building information modeling (BIM) with bills of materials (BOM) is therefore our focus in this paper. This is done in the context of industrialized house-building and the facets which it brings to the subject. The aim of this paper is to present an early endeavor into a BOM based approach for structuring information from BIM models. A demonstration tool was developed, and together with application in a case project from an industrialized house-builder, the generation of BOMs from BIM data is illustrated and discussed. The findings illustrates that we can apply different structures to the information located in our BIM models and that we can produce a BOM perspective on our products. Also, it is highlighted that we still need further studies to better understand how application of BOMs in the context of industrialized house-building is realized.
Energies, Oct 3, 2016
Mass hauling operations play central roles in construction projects. They typically use many haul... more Mass hauling operations play central roles in construction projects. They typically use many haulers that consume large amounts of energy and emit significant quantities of CO 2 . However, practical methods for estimating the energy consumption and CO 2 emissions of such operations during the project planning stage are scarce, while most of the previous methods focus on construction stage or after the construction stages which limited the practical adoption of reduction strategy in the early planning phase. This paper presents a detailed model for estimating the energy consumption and CO 2 emissions of mass haulers that integrates the mass hauling plan with a set of predictive equations. The mass hauling plan is generated using a planning program such as DynaRoad in conjunction with data on the productivity of selected haulers and the amount of material to be hauled during cutting, filling, borrowing, and disposal operations. This plan is then used as input for estimating the energy consumption and CO 2 emissions of the selected hauling fleet. The proposed model will help planners to assess the energy and environmental performance of mass hauling plans, and to select hauler and fleet configurations that will minimize these quantities. The model was applied in a case study, demonstrating that it can reliably predict energy consumption, CO 2 emissions, and hauler productivity as functions of the hauling distance for individual haulers and entire hauling fleets.
Sustainability, Oct 24, 2018
Construction accounts for a considerable number of environmental impacts, especially in countries... more Construction accounts for a considerable number of environmental impacts, especially in countries with rapid urbanization. A predictive environmental assessment method enables a comparison of alternatives in construction operations to mitigate these environmental impacts. Process-based life cycle assessment (pLCA), which is the most widely applied environmental assessment method, requires lots of detailed process information to evaluate. However, a construction project usually operates in uncertain and dynamic project environments, and capturing such process information represents a critical challenge for pLCA. Discrete event simulation (DES) provides an opportunity to include uncertainty and capture the dynamic environments of construction operations. This study proposes a predictive assessment method that integrates DES and pLCA (DES-pLCA) to evaluate the environmental impact of on-site construction operations and supply chains. The DES feeds pLCA with process information that considers the uncertain and dynamic environments of construction, while pLCA guides the comprehensive procedure of environmental assessment. A DES-pLCA prototype was developed and implemented in a case study of an 18-storey building in Northeast China. The results showed that the biggest impact variations on the global warming potential (GWP), acidification potential (AP), eutrophication (EP), photochemical ozone creation potential (POCP), abiotic depletion potential (ADP), and human toxicity potential (HTP) were 5.1%, 4.1%, 4.1%, 4.7%, 0.3%, and 5.9%, respectively, due to uncertain and dynamic factors. Based on the proposed method, an average impact reduction can be achieved for these six indictors of 2.5%, 21.7%, 8.2%, 4.8%, 32.5%, and 0.9%, respectively. The method also revealed that the material wastage rate of formwork installation was the most crucial managing factor that influences global warming performance. The method can support contractors in the development and management of environmentally friendly construction operations that consider the effects of uncertainty and dynamics.
Sustainability, May 7, 2020
In many cold regions around the world, such as northern China and the Nordic countries, on-site c... more In many cold regions around the world, such as northern China and the Nordic countries, on-site concrete is often cured in cold weather conditions. To protect the concrete from freezing or excessively long maturation during the hardening process, contractors use curing measures. Different types of curing measures have different effects on construction duration, cost, and greenhouse gas emissions. Thus, to maximize their sustainability and financial benefits, contractors need to select the appropriate curing measures against different weather conditions. However, there is still a lack of efficient decision support tools for selecting the optimal curing measures, considering the temperature conditions and effects on construction performance. Therefore, the aim of this study was to develop a Modeling-Automation-Decision Support (MADS) framework and tool to help contractors select curing measures to optimize performance in terms of duration, cost, and CO 2 emissions under prevailing temperatures. The developed framework combines a concrete maturity analysis (CMA) tool, a discrete event simulation (DES), and a decision support module to select the best curing measures. The CMA tool calculates the duration of concrete curing needed to reach the required strength, based on the chosen curing measures and anticipated weather conditions. The DES simulates all construction activities to provide input for the CMA and uses the CMA results to evaluate construction performance. To analyze the effectiveness of the proposed framework, a software prototype was developed and tested on a case study in Sweden. The results show that the developed framework can efficiently propose solutions that significantly reduce curing duration and CO 2 emissions.
Sustainability, Jul 19, 2017
Excavators are one of the most energy-intensive elements of earthwork operations. Predicting the ... more Excavators are one of the most energy-intensive elements of earthwork operations. Predicting the energy consumption and CO 2 emissions of excavators is therefore critical in order to mitigate the environmental impact of earthwork operations. However, there is a lack of method for estimating such energy consumption and CO 2 emissions, especially during the early planning stages of these activities. This research proposes a model using an artificial neural network (ANN) to predict an excavator's hourly energy consumption and CO 2 emissions under different site conditions. The proposed ANN model includes five input parameters: digging depth, cycle time, bucket payload, engine horsepower, and load factor. The Caterpillar handbook's data, that included operational characteristics of twenty-five models of excavators, were used to develop the training and testing sets for the ANN model. The proposed ANN models were also designed to identify which factors from all the input parameters have the greatest impact on energy and emissions, based on partitioning weight analysis. The results showed that the proposed ANN models can provide an accurate estimating tool for the early planning stage to predict the energy consumption and CO 2 emissions of excavators. Analyses have revealed that, within all the input parameters, cycle time has the greatest impact on energy consumption and CO 2 emissions. The findings from the research enable the control of crucial factors which significantly impact on energy consumption and CO 2 emissions.
The construction companies are struggling for cost control in construction projects. This is ofte... more The construction companies are struggling for cost control in construction projects. This is often based on cost estimation of scheduled activities. A project may fail due to lack of cash even if it is profitable. The cash flow presents dynamic characteristic which is changing with time progress and it is influenced by the uncertainty project environment, such as supply chain variation, equipment failure and the deviation of working efficiency. At the same time, the increasing market competition forces these companies to transfer from the traditional practice to more advanced and efficient practices, such as lean or flexible production. However, to use lean or flexible production might not prove successful unless the practices are introduced in the right environment. The resources are used in a very efficient way concerning lean, but the practice demand a high degree of predictability. The opposite is true for a flexible production. The resources are not used as efficient but can then on the other hand handle variation better than lean. The research is based on the question: How does managerial operational practices and variation in production influence the cash flow? A model is proposed to simulate and forecast the cash flow considering the uncertainty project environment and selected operational practice. A case study including six scenarios (high and low variation, three operation practices) is used to illustrate the proposed model. A conclusion is that it is important to consider both managerial aspects as well as operational aspects in order to avoid sub-optimization in production. From the cash flow management perspective, the proposed model can assist the contractor to forecast the cash flow and synchronize the operational practices with project environment.
Journal of Cleaner Production, 2017
Improving productivity and innovation is a central challenge in all industries, but particularly ... more Improving productivity and innovation is a central challenge in all industries, but particularly in construction where improvements have been slow. The Swedish Transportation Administration, the largest public client in Sweden, has launched a research and innovation program to increase productivity by foster an industrial approach and identify ways to increase the standardization of products and processes. The use of customizable platforms in bridge construction is in this paper explored as a tool for increasing the standardization. Especially the connection between the product and process platforms is exemplified using a developed bridge concept by a Swedish contractor. The development of modular platforms needs to consider which components and processes that can be specified (standardized) in advance and which that needs to be uniquely adapted to the specific project. Also, the encapsulation of knowledge in standardized design and construction modules in supporting platforms and configuration tools turn tacit personal know-how into formal explicit knowledge that can be managed and continuously improved by the construction company.
Integrating design and production : A component-oriented framework for industrialized housing
This research proposes a component-oriented framework integrating design and production, which en... more This research proposes a component-oriented framework integrating design and production, which enables customer and designer together to customize housing design and avoid ad-hoc design in order to ...
The different stages in construction projects are often separated with little interaction between... more The different stages in construction projects are often separated with little interaction between the different trades. Many researchers proclaim that this separation between design and production limits the buildability of construction design. Thus there is a need for providing knowledge of rules and constraints imposed from production into the design of construction products. A way of integrating production knowledge into design is by implementing platforms in construction products. This study will however investigate if and how configurators could function as carriers of both product and process (production) knowledge within platform thinking. Previous work developing configurators has mainly focused on the efficiency of the design phase and is usually not linked to production improvements and simplifications. By defining a platform for a certain bridge variant within its market segment, the technical solutions can be designed to be flexible while ensuring good buildability in the construction phase. The developed configurator is built in SolidWorks and parametrically coupled using Tacton Studio. The first version generates geometrical drawings, whereas validation of the generated drawings from the configurator compared with the previous designed drawings from a single case study shows that parametric modelling configurators can be used for increasing buildability and efficiency at site.
Projekt: Konfigurationssystem för teknikplattformar
Syfte Syftet med projektet ar att utreda hur utveckling och uppdateringar av tekniska plattforma... more Syfte Syftet med projektet ar att utreda hur utveckling och uppdateringar av tekniska plattformar skall astadkommas och utformas. I en industriell process ar aterkopplingen och uppdateringen av de ...
IABSE Congress Report, 2016
Construction is traditionally a trade that produces unique, one-off products designed specificall... more Construction is traditionally a trade that produces unique, one-off products designed specifically according to the project requirements. However, recently developed flexible product and process platforms in industrialized house building based on the theory of mass customisation offer products that can be customized to a large extent with affordable costs. In this paper we present a framework for how a product and process platform can be developed and used in a traditional engineer-to-order design and construction of transport infrastructure products. The framework is exemplified in a case study, where a typical concrete bridge type is modularised and customized using a product configurator. A database driven simulation model using process patterns and values stored in the platform, is then constructed to test the buildability of the bridge configuration. The results presented provide evidence that product and process platforms can support the design, and planning process of transport infrastructure projects, by integrating product and process information. The results specifically demonstrate how product configuration and database-driven simulation can be used to evaluate the effects of design alternatives and construction methods on performance measures such as productivity and environmental impact.
Condition assessment of a concrete railway bridge in northern Sweden
Fracture mechanics applied to bond
produkt-och-projektutveckling-av-industriellabyggkoncept(15db853c-323b-42d4-9812-ad16ae756f67).ht... more produkt-och-projektutveckling-av-industriellabyggkoncept(15db853c-323b-42d4-9812-ad16ae756f67).html Total number of authors: 7 General rights Unless other specific re-use rights are stated the following general rights apply: Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research.
Evolutionary Game Analysis on the Emission Reduction Decision-Making Behavior of Public Building Owners Based on Carbon Trading
ICCREM 2016, 2017
A probability study of finite element analyses of near surface mounted carbon fibre reinforced polymer bonded to reinforce concrete
8th International Symposium on Fibre Reinforcement for Concrete Structures, 2007
Quantitative analysis using 4D models : an explorative study
Fatigue tension crack growth in plain concrete a creep problem
The VIPP project : results from a case study of the practical application of 3D- and 4D-modelling techniques in design and construction
The VIPP project : results from a case study of the practical application of 3D- and 4D-modelling... more The VIPP project : results from a case study of the practical application of 3D- and 4D-modelling techniques in design and construction
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Papers by Thomas Olofsson