Browsing by Author "Zhao, Jianyu"

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    Applying Heat Maps to Define Workspace in Construction Based on Real-Time Tracking System With Coordinate Positioning Information
    (2020) Zhao, Jianyu; Seppänen, Olli; Peltokorpi, Antti; Department of Civil Engineering; Structures – Structural Engineering, Mechanics and Computation
    he construction jobsites are regarded as highly dynamic and chaotic environment for both workers and management. To ensure efficient task performances, workspace is a key resource in construction sites. Nowadays the technology has enabled better management of onsite resources through location-based methods within lean construction principles, such as Location-Based Management System (LBMS) and Takt planning. Those methods aim to optimize workspace in construction sites consisting of multiple tasks and to eliminate waste related to product and labour flows. To contribute to enhancing those lean construction approaches with attempts to obtain real and objective data, we have developed a real-time positioning system based on Bluetooth Low Energy (BLE) technology where coordinates of workers can be obtained, and heat maps of task-related workspace are generated in real time. This paper aims to develop automated process of generation of workspace based on coordinates of workers and to explore various uses of workspace heat maps to serve the purposes of lean construction principles. The successful implementation of the system in China is analysed and the results suggest that heat maps which use dimensional and temporal positioning data, could be an efficient and convenient method to define workspace of crews onsite.
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    A case study on the implementation of location tracking technologies for productivity monitoring : understanding workers’ acceptance and socio-technical implications
    (Frontiers Media, 2023) Murguia, Danny; Urbina, Alonso; Zhao, Jianyu; Oti-Sarpong, Kwadwo; Seppänen, Olli; Brioso, Xavier; Pontificia Universidad Católica del Perú; Solita Oy; University of Cambridge; Department of Civil Engineering; Department of Civil Engineering
    Automated real-time data collection is becoming more prevalent in construction, with workers’ location data being a pivotal component in detecting poor logistics and inefficient construction flows. However, the collection of location data for productivity monitoring raises significant concerns about privacy and wellbeing implications for workers. Implementing such technological solutions requires an understanding of how humans may respond to sensor-based automated data collection, making this a socio-technical issue. This study identifies the drivers of construction workers’ acceptance of radio-based location tracking technology for productivity measurement using a modified Technology Acceptance Model (TAM) and offers a sociotechnical understanding of technology acceptance with implications for managing how new technologies are introduced on construction projects. Using a large residential project in Lima, Peru as a case study, construction workers were monitored using Bluetooth Low Energy (BLE) technology, and data were gathered using mixed methods. A k-means clustering analysis showed two forms of acceptance among workers: supporters (37%) and acceptance with reservations (63%). Partial least squares Structural Equation Modelling (PLS-SEM) results showed that perceived usefulness and perceived stress underpinned workers’ attitudes and intention to accept the technology. Perceived privacy risk, however, emerged as the sole most significant predictor at the end of the monitoring process. Findings further suggest that workers’ acceptance of the technology is influenced by the perception that it is also beneficial for safety management. Building on the preceding, the paper highlights the need for employee orientation focused on addressing perceived privacy concerns by leveraging positive perceptions about using monitoring technologies for improving onsite safety, logistics and productivity. This requires management of construction firms to develop narratives that reflect their goals for rolling out technologies in ways that ensure workers’ buy-in, and a re-focus on problem framing and collective approaches to identifying functional and less intrusive forms of monitoring technologies.
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    Data Analysis on Applying Real Time Tracking in Production Control of Construction
    (2018-02-12) Zhao, Jianyu; Olivieri, Hylton; Seppänen, Olli; Peltokorpi, Antti; Badihi, Behnam; Lundström, Pontus; Department of Civil Engineering; Department of Communications and Networking; Department of Civil Engineering
    The interest in production control has increased over recent years, especially among lean construction practitioners. Despite of advanced planning and control methods, the data of on-site processes are still typically collected manually. At the same time, technology has been developed to the point where it is possible to remotely locate people, equipment and products in supply chains. Therefore, how to obtain and manage data in construction based on real time tracking is critical to change production control to a more real-time and less laborious process. The availability of real-time, location-based data, opens possibilities to revolutionize production control. This paper proposes a prototype of an intelligent system for real time production control on construction site, defining the types of the tracking data, and investigating the utility of them. The prototype combines Bluetooth and WIFI network as connection methods, and locates resources and their movements in real-time, which can be used as a reference to explore proper solution on construction projects and potentially improve production efficiency, sustainability and management of workers.
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    Hukka LVI- ja sähkötöissä
    (2021-11-26) Seppänen, Olli; Görsch, Christopher; Zhao, Jianyu; Kerttula, Juho; Viitala, Lauri; Rakennustekniikan laitos; Rakennetekniikka, mekaniikka ja laskenta
    Asennustyön lisäksi LVI- ja sähköasentajat käyttävät aikaa erilaisiin tukeviin toimintoihin, kuten materiaalien haalaukseen tai työstämiseen työmaalla. Tukevat toiminnot ovat nykyprosessissa välttämättömiä mutta niidenkin osuutta voidaan vähentää esimerkiksi työnjakoa muuttamalla tai esivalmistusastetta kasvattamalla. Erityisen kiinnostuksen kohteena tuottavuuden parantamisessa on kuitenkin aika, joka menee prosessin kannalta tarpeettomiin asioihin, esimerkiksi uudelleen tekemiseen tai odotteluun. Aiemmassa tutkimuksessa on tutkittu hukkaa hyödyntäen kypäräkameroita ja sisäpaikannusta mutta tutkimukset eivät keskittyneet yksittäisiin työlajeihin. Tämän tutkimuksen tavoitteena oli keskittyä LVI- ja sähkötöihin ja selvittää hukatun ajan määrää sekä sen juurisyitä ja tehdä tuloksiin pohjautuvia suosituksia tuottavuuden parantamiseksi. Tavoitteena oli päästä aiempia tutkimuksia syvemmälle hukan juurisyihin yhdistelemällä sekä määrällistä että laadullista tietoa ja luokittelemalla asentajien ajankäytön lisäksi hukatun ajan tyyppejä ja asentajilta puuttuvia aloitusedellytyksiä. Työmaatutkimusta tehtiin neljällä työmaalla. Tietoa kerättiin kypäräkameroilla ja sisäpaikannuksella sekä haastattelemalla työmaatutkimukseen osallistuneita asentajia. Viestinnän toimivuutta selvitettiin laajalla kyselytutkimuksella ja sen pohjalta tehdyillä haastatteluilla. Sähkötöissä asennusajan osuus oli 24 % ja putkitöissä 15 %. Asennusajan matala osuus selittyi erityisesti materiaalilogistiikan haasteilla putkitöissä ja edeltävien tehtävien valmiudella sähkötöissä. Mukaan valikoitui erilaisia työmaita, joilla oli omat erityispiirteensä. Työ oli tuottavinta kaikkein laajimmalla kauppakeskustyömaalla (asennustyön osuus 25 %), jossa pääurakoitsija oli kehittänyt tuotannonohjausta ottamalla käyttöön tahtituotantomenetelmän. Työmaalla, joissa asennukset olivat viivästyneet koronapandemiasta johtuen asennustyön osuus oli vain 14 %. Viestinnän suhteen päätulos oli, että asentajat tarvitsevat huomattavasti enemmän tietoa kuin saavat nykyprosessissa ja heillä on halua osallistua enemmän esimerkiksi työnsuunnitteluun. Kaikkien asentajien tuottavuus kärsi merkittävästi suunnittelun haasteista. Tärkeimmät keinot tuottavuuden parantamiseksi ovat suunnittelun laadun parannus, työnsuunnittelun kehitys, materiaalilogistiikan kehitys sekä esivalmistusasteen nosto. Suunnitelmien yhteensovitus tehdään nykyään työmaalla asentajien toimesta. Prosessi pitäisi siirtää suunnitteluvaiheeseen, koska se selittää ison osan hukatusta ajasta. Suunnittelun laadun parannus on myös edellytys laajemmalle esivalmistukselle, joka voi tapahtua tehtaalla tai työmaalla sille varatussa tilassa. Työnsuunnitteluun pitäisi osallistaa enemmän työryhmien edustajia ja tarvitaan jatkuvasti päivittyvä aikataulu, josta kaikki näkevät, mitä pitäisi tehdä seuraavaksi. Materiaalilogistiikka on tärkeässä roolissa erityisesti putkitöissä. Kehitystä tarvitaan varastojen hallintaan ja materiaalitilauksiin. Kaikki materiaalit olisi hyvä olla pyörillä, jotta ne olisivat helposti siirrettävissä ja logistiikkapalveluita tulisi hyödyntää nykyistä enemmän.
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    Indoor Tracking of Construction Workers Using BLE: Mobile Beacons and Fixed Gateways vs. Fixed Beacons and Mobile Gateways
    (IGLC.net, 2019) Dror, Erez; Zhao, Jianyu; Sacks, Rafael; Seppänen, Olli; Department of Civil Engineering; Structures – Structural Engineering, Mechanics and Computation; Technion - Israel Institute of Technology
    Automatic resource location monitoring in construction projects empowers managers to make data driven decisions that improve project workflow. Monitoring data can be processed to measure workflow quality and thus for better understanding of effectiveness and efficiency. We compare two methods for deployment of Bluetooth Low Energy (BLE) beacons for indoor resource monitoring - mobile beacons and fixed gateways (MB) vs. fixed beacons and mobile gateways (FB). BLE beacons can be fixed to walls or carried by workers, and can be fixed to material containers and equipment. Using gateways, such as raspberry pi computers or smartphones, one can easily and automatically monitor resource locations. Several field experiments were conducted, both in the laboratory and in construction sites in Finland, Israel, Peru, Netherlands and China. Technical aspects such as setup, direct cost, feasibility and accuracy were compared for two methods - mobile beacons and fixed gateways vs. fixed beacons and mobile gateways - and the performance of each method in providing the data needed for lean construction workflow assessment was assessed. Both methods are effective in monitoring resource locations but differ in their feasibility of implementation in construction sites and in the utility of the data they provide in terms of identifying value adding activities.
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    Intelligent Construction Site: On Low Cost Automated Indoor Localization Using Bluetooth Low Energy Beacons
    (2019-11) Badihi, Behnam; Zhao, Jianyu; Zhuang, Siyan; Seppänen, Olli; Jäntti, Riku; Communication Engineering; Structures – Structural Engineering, Mechanics and Computation; Department of Civil Engineering; Department of Communications and Networking
    The construction jobsites are highly dynamic environments involved with labor-intensive and manual tasks that suffer from inefficiency and mis-management. To remedy these issues, production control within the scope of lean construction has been a hot topic in academia and industry. To this end, we have developed a real-time coordination-based tracking system using low-cost Bluetooth Low Energy beacons. This system is implemented according to the trilateration method in order to acquire the real-time location of resources and movement trajectory in the construction jobsites. The prototype is tested and implemented in the real construction site in China. The results show that the implemented tracking system can be used in the construction sites depending on the accuracy level required in the project.
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    Production Control Using Real-Time Monitoring in Construction
    (Aalto University, 2022) Zhao, Jianyu; Olivieri, Hylton, Prof., IPT - Institute for Technological Research, Brazil; Rakennustekniikan laitos; Department of Civil Engineering; Insinööritieteiden korkeakoulu; School of Engineering; Seppänen, Olli, Prof., Department of Civil Engineering, Aalto University, Finland; Peltokorpi, Antti, Prof., Aalto University, Department of Civil Engineering, Finland
    Construction projects are known to be full of complexity because they interconnect high quantities of elements, including labor, tasks, and components. The complexity often results in risks such as poor work productivity and interruptions of production workflows, which further leads to unexpected and wasteful activities on-site. A well-functional production control system in construction is important in enabling smooth workflows with minimal waste and variability. Waste measurement is difficult and complex through conventional measurement techniques in construction. For instance, notable waste happens in labor movement and material flows, but the challenges of measuring the waste are still hard to address in construction. Therefore, it is of great benefit to develop a scalable and automated system that measures wasteful events and improves site operations in construction. If an automated real-time monitoring system in construction can be implemented with ease and satisfactory coverage and accuracy, it is then possible to assess the movement of labor and materials on-site. Next, the analyses of movement can be conducted to reflect upon the magnitude of variability at the project and task levels, which helps waste elimination and improvement of production control. The overall objective of the research is to improve production control in construction by estimating workers' presence on-site at the project and task levels to support task progress monitoring and to assess task workflow and material management practice. First, the thesis demonstrates how the proposed real-time monitoring system can be implemented in different types of indoor construction projects. The data accuracy and coverage of the system were evaluated, and heuristics were also proposed to improve the system's coverage. With this method, presence indices were calculated, matching previous studies in which value-added time was evaluated and the data were collected manually. Second, the thesis illustrates how the system can be installed to detect task start and finish times, measuring and validating task progress data automatically. Third, the thesis also shows how the proposed system could be applied for the automated detection and analyses of time-matching level of materials and workers based on their uninterrupted presence, which can be used to evaluate the kitting material solution practice. From a research perspective, this study makes it possible to measure the impact of construction management or digitalization interventions on the long-term presence of workers and materials in work locations. From a practical standpoint, managers can use the suggested presence information to compare efficiency in different projects. For project management, the daily measurement of presence in work locations could identify problems that are currently unknown to the management or highlight the impact of problems, e.g., the productivity impacts of delays.
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    Real-time resource tracking for analyzing value-adding time in construction
    (Elsevier, 2019-08-01) Zhao, Jianyu; Seppänen, Olli; Peltokorpi, Antti; Badihi, Behnam; Olivieri, Hylton; Department of Civil Engineering; Department of Communications and Networking; Structures – Structural Engineering, Mechanics and Computation
    Improving the effectiveness of production control has attracted the interest of researchers and lean construction practitioners over recent years, through techniques such as Last Planner System (LPS) and Location-based Management System (LBMS). However, in these techniques, data collection and analysis still remain manual. Remotely locating workers on site has been suggested as a potential technology to collect crucial data required for production control. The purpose of this study is to test the applicability of a real-time tracking system for collecting data for production control in different types of construction projects. We applied Bluetooth Low Energy (BLE) technology in real-time tracking of workers in three case projects, including residential, office building, and plumbing renovation. We compared various tracking device placement strategies and analyzed the share of uninterrupted presence of workers in work locations based on the collected data. The findings show that both location-based and time-based information of workers can be obtained in real time from the proposed system, but issues of accuracy and coverage need to be considered when defining the data collection plan for each project. Accuracy and coverage issues can be resolved to a significant degree by applying heuristics in data analysis rather than investing in a more sophisticated tracking technology. The conclusion is that real-time tracking technologies are ready for implementation when certain heuristics and guidelines for installation are followed. It is possible to calculate a real-time presence index on a construction site. These data could be used to evaluate the impact of construction management interventions on waste on-site.
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    Real-time Tracking for Intelligent Construction Site Platform in Finland and China: Implementation, Data Analysis and Use Cases
    (2019) Zhao, Jianyu; Zhang, Jinyue; Seppänen, Olli; Structures – Structural Engineering, Mechanics and Computation; Tianjin University; Department of Civil Engineering
    Production control, especially lean construction approaches, has necessitated the needs of eliminating waste onsite. Though the collaborative methods such as Location-Based Management System (LBMS) and Last Planner System (LPS) have proven the improvement of productivities, the process of data collection has still remained manual, which could result in inaccuracy and incompletion. Automatically locating workers has been proposed to enable a method for production control in construction projects onsite. Thus, a platform is sought where an easy and passive tracking system is designed to enhance the production control processes. In recent years, Finland is experiencing crucial transition from traditional production to digitalization formation while China has been a model where massive construction takes place as cities are expanding over the economic booming. The extensive building activities require a smooth and automated tracking system that can control and manage resources onsite to monitor in real time and examine the productivities more efficiently. This paper presents case studies in Finnish and Chinese construction sites where the proposed real-time tracking system was implemented, and the tracking data were analyzed for purposes of operations management. The model combines Bluetooth Low Energy (BLE) technology and 3G/4G network as connection methods, and explores the movements and time information of workers onsite, aiming to establish an intelligent construction site platform, which can be used for managing resource flow within lean principles in Finland and China.
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    Risk Assessment of Housing Market Segments: The Lender’s Perspective
    (2018-10-26) Wilhelmsson, Mats; Zhao, Jianyu; KTH Royal Institute of Technology; Department of Civil Engineering
    It is well known that risk factors influence how investment portfolios perform from a lender’s perspective; therefore, a thorough risk assessment of the housing market is vital. The aim of this paper was to analyze the risks from housing apartments in different housing market segments by using the Stockholm, Sweden, owner-occupied apartment market as a case study. By applying quantitative and systems engineering methods, we (1) established the relationship between the overall housing market and several housing market segments, (2) analyzed the results from the quantitative model, and (3) finally provided a feasible portfolio regarding risk control based on the given data. The goal was to determine how different housing segment factors could reveal risk towards the overall market and offer better outlooks for risk management when it comes to housing apartments. The results indicated that the risk could be reduced at the same time as the return increased. From a lender’s perspective, this could reduce the overall risk.
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    Using real-time indoor resource positioning to track the progress of tasks in construction sites
    (FRONTIERS MEDIA SA, 2021-04-29) Zhao, Jianyu; Pikas, Ergo; Seppänen, Olli; Peltokorpi, Antti; Department of Civil Engineering; Structures – Structural Engineering, Mechanics and Computation
    Lean construction methods have demonstrated potential to improve construction productivity. For example, the location-based management system and the last planner system have increased the reliability of planning and control in construction production. However, these benefits are often reduced because of inaccurate manual data collection. To alleviate these problems, technologies for automated monitoring of workers have been developed to identify site events in chaotic environments. This paper aims to investigate whether a Bluetooth low-energy-based real-time indoor positioning system can monitor task progress from workers’ presence. Our findings suggest that the proposed system is a feasible solution for monitoring task-level progress when there are explicit dependencies between tasks. This method could automatically detect task start and finish times and estimate the hours required to complete a task. This enables the measurement of waste hidden inside tasks, which allows for interventions for improving flows and eliminating waste.
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    Using Real-Time Tracking of Materials and Labor for Kit-Based Logistics Management in Construction
    (FRONTIERS MEDIA SA, 2021-09-03) Zhao, Jianyu; Zheng, Yuan; Seppänen, Olli; Tetik, Müge; Peltokorpi, Antti; Department of Civil Engineering; Structures – Structural Engineering, Mechanics and Computation
    Improved productivity and the elimination of waste are key goals for lean methods in construction production control. One such lean method is a kit-based logistics management in which task-based materials are delivered just-in-time and aligned with assembly operations on-site. Digital platforms could enable a situational awareness of work and material flows, potentially increasing the benefit and applicability of kitting. The aim of the current research is to utilize a real-time indoor tracking of material and labor flows to evaluate an assembly kit–based management of construction projects. We propose a linked data framework to connect labor, material, and scheduling information to integrate heterogenous data. The contribution of the study is threefold: first, a feasible method is developed to enable real-time detection of work and material flows inside the building for logistics management purposes. Second, several key performance indicators for effective evaluation of kit-based production flow in construction are provided, which allows management to tackle root causes of problems and to enhance timely and productive logistic solutions. Thirdly, by applying the linked data method, the study introduces a novel approach to integrate heterogenous data from both indoor tracking and schedules.