BIM for supply chain management in construction. Setting up contractor's BIM-based supply chain

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Scuola di Ingegneria Industriale e dell’Informazione

Master of Science in Management Engineering – Milano Bovisa

BIM for Supply Chain Management in Construction

Setting up Contractor’s BIM-based Supply Chain

Supervisor

| prof. Mauro MANCINI, Politecnico di Milano

Co-Supervisor

| Alessio Domenico LETO, Politecnico di Milano

Co-Supervisor

| prof. Carlo RAFELE, Politecnico di Torino

Student

| Marijana Zora Kuzmanović

ID Number

| 892241

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Acknowledgements

I wish to express my sincere gratitude to professor Mauro Mancini for providing me with the opportunity to work on this interesting topic. Throughout this research work, I have realized the beauty of BIM which triggered my sincere desire to continue exploring its potential.

During this journey, I was able to get in contact with BIM industry experts, hear their practical experience and feel their enthusiasm towards opportunities which BIM may unlock in construction, for which I am very grateful.

I also wish to thank to Alessio, who was always there to guide me and closely follow my work. Finally, I would not have made it up to here without the support of my mother and sister, closest friends and coinquilini who were a bit tired of listening to the newest BIM-related insights I was gathering throughout the work.

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Abstract

Construction enterprises mostly seek to implement BIM in the pre-construction phase, for 3D design visualization and clash detection (Bosch et al., 2017). However, BIM generated information is not fully exploited within the activities of construction management, fabrication, and erection (Aram et al., 2013), not to mention for reaching full collaboration along the complex construction supply chains. That complexity can be attributed to the high fragmentation present among the construction project actors, due to the presence of various multi-disciplinary companies with unintegrated operational processes for collaboration (Nam and Tatum, 1992; Robson et al., 2014; Dainty et al., 2001). Due to the project-based nature of their collaboration, not so much effort has been put in managing the supply chain, rather in risk shifting towards the upstream part of the chain and last tier suppliers (O’Brien et al., 2009). These practices result in poor communication among supply chain actors, based on 2D document management and a lot of rework. Direct consequences are lack of material delivery transparency and high variability of data long the supply chain, which continue prolonging the project deadlines and increasing the costs.

One of the methodologies which has a strong potential for enhancing the performance of construction supply chains is Building Information Modelling (BIM), as a technological enabler for up to date information exchange and collaboration between the actors (Eastman et al., 2008; Bankvall et al., 2010; Bryde et al., 2013).

In that sense, this research tries to define the potential BIM-enabled tools which could provide supply chain members with timely information exchange and allow them to take control of their highly interdependent activities. Taking control is very relevant since final value delivered to the Client is a direct function of the effective multi actor chain management, as around 75% of the value of the construction works is contributed by suppliers and subcontractors (Dubois and Gadde, 2000). Focus of the research has been set on the construction phase of project lifecycle, by listing proven BIM applications within the building components procurement, their production off-site, transportation and logistics as well as on-site assembly.

However, due to the socio-technological nature of BIM, exploration of sound environment for achieving transparent practices was needed, by investigating the current relationships among supply chain members as well as their perception regarding the constraints for achieving BIM-based supply chain management. These constrains may occur in different

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dimensions on inter-organizational level: social, organizational, technological and economic. Only after understanding the potential which may be achieved by managing supply chain with BIM and perceived constraints for reaching that potential, a guideline has been produced, mainly concerning main contractor as the initiator of such practices.

Finally, main finding is related to the potential reinforcement between BIM and supply chain. While the supply chain shall be stable and formed in a trusting environment (based on principles of partnerships for tighter integration) in order to grasp the full value of BIM, BIM can be used as a mean for regulating and tracking the information and material flows among the actors in a standardized code-based and transparent form. By doing so, each supply chain member is enriching building components with their piece of information and in the moment of those information creation throughout the well-defined and regulated collaboration processes enabled by BIM. Indeed, by pursuing such practices, value-added in terms of rich building information models may be handed over to the Clients (besides the physical assets) in the form of digital twins as a final result of successful collaboration. This way of working may shift the competition in the construction sector from price based to value based, as a result of supply chain management supported with BIM methodology. Furthermore, this strategy may allow construction SMEs to gain competitive advantage over the big industry players, by having whole supply chain by their side.

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Sommario

Le imprese di costruzione implementano il BIM principalmente nella fase di pianificazione, per la visualizzazione di progetti in 3D e per il rilevamento di conflitti (clash detection) tra gli elementi costruttivi (Bosch et al., 2017). Tuttavia, le informazioni generate dal BIM non vengono sfruttate appieno nell'ambito delle attività di gestione e installazione in cantiere (Aram et al., 2013), e la condivisione di tali informazioni è molto scarsa lungo le complesse catene di approvvigionamento del settore. Tale complessità può essere attribuita all'elevata frammentazione presente tra gli attori del progetto di costruzione, a causa della presenza di varie imprese multidisciplinari con processi operativi non fondati sulla collaborazione (Nam e Tatum, 1992; Robson et al., 2014; Dainty et al., 2001). A causa della sua natura basata sul progetto, il settore delle costruzioni non ha fatto molti sforzi nella gestione della catena di approvvigionamento o per condividere equamente i rischi tra gli attori (O’Brien et al., 2009). Le attuali pratiche comportano una scarsa comunicazione tra gli attori della catena di approvvigionamento, basata su una frequente rielaborazione dei documenti condivisi. Conseguenze dirette di questa situazione sono la mancanza di trasparenza nel conferimento dei materiali e l'elevata variabilità dei dati lungo la catena di approvvigionamento, con conseguenti aumenti dei costi e ritardi nella consegna del progetto. Una delle metodologie che sembrerebbe avere un forte potenziale nel miglioramento delle prestazioni delle catene di approvvigionamento nel settore delle costruzioni è il Building Information Modeling (BIM), una metodologia digitale basata sullo scambio delle informazioni e sulla collaborazione tra gli attori del progetto (Eastman et al., 2008; Bankvall et al., 2010; Bryde et al., 2013).

La presente tesi si propone l’obbiettivo di definire i potenziali strumenti basati sul BIM che potrebbero fornire ai membri della catena di approvvigionamento uno scambio tempestivo delle informazioni, consentendo loro il controllo delle attività altamente interdipendenti. Assumere il controllo di ciò che si sta producendo è molto rilevante, poiché il valore finale consegnato al cliente è una funzione diretta dell'effettiva gestione della catena multi-attore; infatti, circa il 75% del valore delle opere di costruzione è fornito da fornitori e subappaltatori (Dubois e Gadde, 2000). Il focus della ricerca è stato posto sulla fase costruttiva del progetto, elencando le applicazioni BIM già collaudate nell'approvvigionamento dei componenti dell'edificio, nella loro produzione fuori sede, nel trasporto e nella logistica, nonché nell'assemblaggio in situ. Tuttavia, a causa della natura

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socio-tecnologica del BIM, è stata necessaria l'esplorazione di un ambiente collaborativo per raggiungere pratiche trasparenti, indagando le relazioni attuali tra i membri della catena di approvvigionamento e la loro percezione riguardo ai vincoli per la realizzazione della catena di approvvigionamento basata sul BIM. Questi vincoli possono verificarsi secondo diverse dimensioni a livello inter-organizzativo: sociale, organizzativo, tecnologico ed economico. Solo dopo aver compreso il potenziale che può essere raggiunto gestendo la catena di approvvigionamento con il BIM e percependo i vincoli per raggiungere quel potenziale, è stata prodotta una linea guida, principalmente riguardante l’appaltatore principale, considerato come il precursore di tali pratiche.

Il risultato principale di tale lavoro è legato al potenziale rafforzamento tra la metodologia BIM e la catena di approvvigionamento. Mentre la catena di approvvigionamento deve essere stabile e formata in un ambiente pienamente collaborativo (basato su principi di partnership per una più stretta integrazione), il BIM può essere utilizzato come mezzo per regolare e tracciare i flussi di informazioni e materiali tra le parti interessate in una forma standardizzata, codificata e trasparente. In questo modo, ciascun membro della catena di approvvigionamento arricchisce i componenti dell'edificio delle loro informazioni, basandosi su processi di collaborazione ben definiti e regolamentati dal BIM. In effetti, perseguendo tali pratiche, il valore aggiunto in termini di modelli ricchi di informazioni può essere consegnato al cliente (oltre alle risorse fisiche) sotto forma del gemello digitale dell’edificio, quale risultato finale di una collaborazione ben riuscita. Questo modo di lavorare, in conseguenza della gestione della catena di approvvigionamento supportata dalla metodologia BIM, può incentivare una concorrenza basata sul valore aggiunto piuttosto che sul prezzo. Inoltre, questa strategia può consentire alle piccole e medie imprese delle costruzioni di ottenere un vantaggio competitivo rispetto alle grandi imprese del settore, sfruttando interamente la propria catena di approvvigionamento.

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List of Tables

Table 1. Areas for boosting construction productivity ... 22

Table 2. LOD requirements for certain BIM applications ... 29

Table 3. Typical configurations of construction supply chain ... 41

Table 4. Addressing Construction Supply Chain issues with BIM ... 53

Table 5. Profile of the interviewees ... 67

Table 6. Potential of BIM by construction supply chain area ... 71

Table 7. Perception regarding opportunities in SCM enabled by BIM ... 84

Table 8. Perception regarding supply chain areas of improvement ... 85

Table 9. Solving Construction Supply Chain issues with BIM ... 86

Table 10. Supplier selection criteria ... 90

Table 11. Nature of partnerships in the supply chain ... 91

Table 12. Barriers for supply chain partnerships ... 92

Table 13. Perceived constraints for BIM implementation ... 93

Table 14. Perceived BIM-based SCM feasibility for the Contractors ... 94

Table 15. Perceived BIM-based SCM feasibility for the Subcontractors/Suppliers ... 95

Table 16. How to incentivize suppliers for BIM-based SCM ... 95

Table 17. Future development of SCM with BIM ... 96

Table 18. Opportunities offered by BIM for supply chain management ... 115

List of Figures

Figure 1. Research Methodology adopted ... 18

Figure 2. Overall research framework ... 19

Figure 3. Core causes for low productivity in construction sector ... 22

Figure 4. BIM Maturity levels ... 24

Figure 5. Value of 3D BIM ... 26

Figure 6. Overview of different LODs ... 27

Figure 7. BIM process flow - Starting from 2D drawings ... 30

Figure 8. BIM process flow - Collaborative model ... 30

Figure 9. BIM process flow - Including fabricators ... 31

Figure 10. Areas of enterprise BIM-based transformation ... 34

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Figure 12. The 3 Vs of Construction Project Data ... 39

Figure 13. “The five rights” of logistics ... 44

Figure 14. General issues along the Construction Supply Chain ... 47

Figure 15. Traditional (left) and BIM-enabled (right) information exchange ... 54

Figure 16. Overview of the BIM-based supply chain model ... 55

Figure 18. Research Methodologies adopted ... 62

Figure 19. BIM for SCM survey questionnaire structure ... 65

Figure 20. Role of the companies in the supply chain ... 66

Figure 21. Annual turnover range ... 66

Figure 22. Types of projects executed ... 66

Figure 23. Number of employees ... 66

Figure 24. BIM-enabled material procurement ... 72

Figure 25. Visualizing status of prefabricated components ... 76

Figure 26. Connecting the supply chain with RFID tags ... 80

Figure 27. BIM-enabled components status monitoring ... 81

Figure 28. Overview of barriers perceived for BIM-based SCM ... 97

Figure 29. Guideline for setting up BIM-based SCM ... 109

Figure 31. Overview of barriers perceived for BIM-based SCM ... 116

Figure 32. BIM-based SCM implementation guideline ... 117

List of Abbreviations

BDOs | BIM Digital Objects

BIM | Building Information Modeling CDE | Common Data Environment CSC | Construction Supply Chain SC | Supply Chain

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1 Introduction

This chapter briefly explains the purpose of the research, methodology used for conducting the same as well as the overall structure of the thesis work.

1.1 Research Purpose

This research aims at understanding the potential applications of Building Information Modeling (BIM) for Supply Chain Management (SCM) in Construction industry, their benefits, barriers and enablers for implementation. Focus has been set on the construction phase of the project lifecycle, and the perspective taken was that of the general contractor, as the potential initiator of such practices and integrator of various project supply chain actors.

The relevance of this exploratory research mainly lies in the lack of BIM utilization for enhancing construction industry collaboration, especially those related to the complexity of supply chain management. Namely, construction enterprises mostly seek to implement BIM in the pre-construction phase, for 3D design visualization and clash detection (Bosch et al., 2017). However, BIM generated information is not fully exploited within the activities of construction management, fabrication, and erection (Aram et al., 2013), not to mention for reaching full collaboration along the supply chain. Therefore, initial part of the research focuses on understanding the potential applications in which BIM may support execution of complex and highly intertwined supply chain management activates. That complexity can be attributed to the high fragmentation present among the construction project stakeholders, due to the presence of various multi-disciplinary companies with unintegrated operational processes for collaboration (Nam and Tatum, 1992; Robson et al., 2014; Dainty et al., 2001). Since the overall performance of the supply chain is dependent on multiple actors besides the contractor (designers, numerous subcontractors and suppliers of building materials/components), tools and methodologies for transparent and real-time communication are needed to improve the overall process of value delivery to the Client. Moreover, by effectively managing the supply chain, contractors should be able to take more control of their processes and reduce wastes in terms of quality, costs and time which are still present. Indeed, taking control is crucial due to the mutual interdependence among supply chain actors, who shall maintain their relationships until the project targets have been achieved (Frazier, 1983). One of the methodologies which has a strong potential for

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harmonizing project-based supply chains is Building Information Modelling (BIM), as a technological enabler for up to date information exchange and collaboration between the actors (Eastman et al., 2008; Bankvall et al., 2010; Bryde et al., 2013).

Moreover, it was also needed to gather the perception regarding the feasibility of achieving transparent supply chain practices offered by BIM. Therefore, survey questionnaire has been distributed on a European level (and wider) in order to understand whether the main barriers perceived by multidisciplinary supply chain members for adopting such transparent supply chain practices may be country specific and/or related to their openness for partnering and collaboration. The inspiration for such survey arises after reviewing significant research efforts within the Dutch construction industry (Papadonikolaki et al. 2015; 2016, 2017), with a focus on inter-organizational level of BIM applications for harmonizing information flows and relationships across the supply chain. However, peculiarity of Dutch industry is related to well established SCM practices due to the culture of long-term partnerships which may already be ready to grasp BIM as a technological enabler. Thus, Costa et al. (2019) propose a further research addressing countries with more significant construction activities segmentation, since the barriers and relationships among actors could be context specific.

Finally, after the perception of the practitioners regarding feasibility of achieving collaborative SCM practices has been gathered, this research tries to provide a guideline in the form of three blocks as enablers for reaching the state of BIM-ed supply chain: people, process and technology, as the connection of these three may enable integration. These guidelines have been established after investigating practitioners’ opinion on potential ways in which barriers for collaboration may be overcome.

1.2 Research Methodology

In order to cover the above-mentioned research topic in a comprehensive way, answering to the three research questions has been set as a main objective of the thesis (represented below). The first one concerns structuring the applications of BIM for improving different areas of the project supply chain and benefits which may be achieved, while the second one deals with understanding the perceived barriers which may arise when trying to achieve such practices. Thus, the first question aims at answering the WHAT and WHY part of the topic BIM for Supply Chain Management, to map the potential applications and benefits

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which stem from implementation of BIM for information and material management practices. However, certain resistance for BIM adoption may arise, thus posing the need for second research question. Finally, the third question seeks to gather insights from the practice by understanding the processes of collaboration enabled by BIM and core enabling factors for reaching those. Therefore, the third question answers the HOW part of actually setting up the BIM-enabled supply chain. The three research questions and structure of the answers for those are presented below.

RQ.1 Which are the opportunities and trends of BIM-based Supply Chain?

Following the logic of material and information flows from defining them within the 3D environment to their installation on site, opportunities have been classified within four “big blocks” of construction supply chain:

§ Procurement of building material/components;

§ Off-site production of building materials/components;

§ Transportation and Logistics; § On-site Assembly/Construction.

However, since the construction supply chain actors and activities are tightly intertwined, consideration of overall benefits regarding information and material flows will be presented as well.

RQ.2 Which are the common barriers for establishing BIM-based Supply Chain?

Innovative technological tools such as BIM impose various barriers for adoption within the single organization per se. However, in order to reach above-mentioned opportunities along the whole project supply chain, observation of barriers on inter-organizational level is needed as well. For the sake of understanding multidimensional factors influencing the adoption of BIM for supply chain management, the barriers have been clustered into four main blocks:

§ Economic – Lack of financial resources for investing into BIM solutions;

§ Organizational – Complexity of integrating processes and defining responsibilities;

§ Technological - Appropriate software infrastructure for collaboration;

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RQ. 3 How could a Contractor set up a BIM-based Supply Chain?

The answer to this research question seeks to provide a guideline and the key success factors for setting up a BIM-enabled project supply chain, mostly concerning people, processes and technology, from inter-organizational perspective, since supply chain actors are highly interdependent and final value delivered to the Client is a direct function of multidisciplinary collaboration.

Throughout the research work, different methods were utilized for gathering specific insights related to the three above-mentioned research questions. The choice of the methodology for answering the specific research questions is presented in the Figure 1 below.

Figure 1. Research Methodology adopted 1.3 Structure of the Thesis work

The following chapter (Chapter 2), Literature review, seeks to gather the existing research on the two distinct topics of BIM and SCM separately, starting from understanding the basic concepts of Building Information Modeling and its transformative power as a technological support in the construction industry. Secondly, overview of construction supply chain and current supply chain management practices have been presented, as a base for understanding the issues which construction project actors are facing nowadays. Finally, these two are merged together in a structured form to present potential of BIM for improving collaborative practices along the supply chain, mostly concerning the downsides

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stemming from the ways that current project supply chain operate. Finally, output of this chapter are the gaps found in the literature, which have been used as a base for setting up the research questions, as well as hypothesis under which the research has continued. The third chapter, Research Methodology, presents the goals of the work in the form of research questions stemming from gaps identified in the literature, methodology used (literature review, survey and interviews) for reaching those goals and overall planned structure of the guidelines in which unification of the findings will be presented. Due to the exploratory nature of the research, a mixed method was used to gather the data from multiple sources.

Following chapter – Findings presents the insights gathered from practitioners from two sources: survey and interviews, which are mainly answering to HOW question of establishing BIM-based supply chain management and barriers which may appear when doing so. However, in this chapter literature was used as well, as a secondary source to answer to the question WHAT, by listing proven potential applications of BIM for different supply chain areas (the four big blocks above-mentioned). Finally, the findings are unified in form of a structured guideline for establishing BIM-based supply chain solution, which is the ultimate goal of the research work, presented in Figure 2 below.

Figure 2. Overall research framework

Finally, the fifth chapter Discussion and Conclusion sums up the overall research work done, presents the limitations of the study as well as suggestions for future research work.

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2 Literature Review

The aim of this chapter is to have a comprehensive overview of the academic research regarding Building Information Modelling, Construction Supply Chain (CSC) and the integration of the two, with the focus on the Supply Chain of the Contractors and their interaction with other Construction Supply Chain actors, mainly throughout the construction phase. Overview is crucial to provide possible directions for supply chain management improvement with the support of BIM as a technological enabler for real-time information sharing and integration among the stakeholders.

Therefore, main outcome of the literature review is a draft of the hypothesis about the current state of CSC and BIM, as well as identification of research gaps which are crucial for setting up the research questions and overall objectives of the work.

2.1 Challenge in the Construction Sector

Construction sector has been criticized for many inefficiencies, among which productivity stagnation and low digitalization index (McKinsey Global Institute, 2017). On the one side, demand for construction is expected to grow to $17.5 trillion by 2030 (Boston Consulting Group, 2015), while there is the question whether the supply side (construction enterprises) is ready to cope with it. This era of digital disruption shall not be considered as a threat for traditional players due to accelerating number of new entrants with innovative solutions, but rather as an opportunity to learn, collaborate and increase competitiveness on the market. The opportunity is certainly there, and contractors shall seize it, while changing their day-to-day business practices is certainly needed.

As researched by McKinsey Global Institute (2017), the core of the construction industry stagnation can be attributed to: “Misaligned incentives among owners and contractors and with market failures such as fragmentation and opacity”.

In order to understand the directions needed for change, it is relevant to identify issues the industry has been facing according to their source of origin. Namely, Figure 3 below demonstrates issues at three different levels, such as those related to external forces, industry dynamics and firm’s operational practices. Within the following chapters, scope of the research will focus on the latter two.

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Figure 3. Core causes for low productivity in construction sector

Source: Adopted from McKinsey Global Institute, 2017

Nevertheless, according to McKinsey Global Institute (2017) there are some macro areas from which the change of practices could start, with a potential of increasing sector’s productivity by 50 to 60%. Those relevant to the scope of the research work are presented in Table 1 below.

Table 1. Areas for boosting construction productivity

Source: Adopted from McKinsey Global Institute, 2017

First potential area of improvement concerns industry practices, where collaboration and partnerships as seen as good starting point for change. On the other hand, advancement in supply chain management practices and technology (digitalization) can significantly impact the productivity of the sector and are related to the capabilities of the firm. Implementation of technologically advanced solutions can secure the solid competitive positioning of the companies, while lowering costs and increasing productivity of day-to-day business. As

Area of improvement Possible direction Impact on

productivity

Collaboration and contracting

Seek for collaboration practices – Integrated Project Delivery (IPD), long-term partnerships and “single source

of truth” 8-9%

Procurement and supply chain management

Digitalize procurement and supply chain flows, improve contractor-supplier transparency and reduce delays, strive

for just-in-time principle 7-8%

Technology Make BIM universal, use cloud and IoT for accurate real _{time data} 14-15% § Increasing project complexity; § Extensive regulation; § Informalities and potential for corruption. § Lack of transparency within the sector; § High industry

fragmentation;

§ Contractual incentives are misaligned.

EXTERNAL FORCES INDUSTRY DYNAMICS

§ Underinvestment in digitalization, innovation and capital;

§ Poor project management and execution practices.

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reported by Boston Consulting Group (2017), digital solutions can provide annual global cost savings up to $1.2 trillion in the engineering and construction phase (concerning non-residential projects only).

Therefore, the following section of the literature review will focus on investigating issues and opportunities within these areas previously mentioned, where the area of technological solutions will tackle solely BIM as the technological enabler.

2.2 Building Information Modeling

This sub-section deals with the general definitions and characteristics of Building Information Modeling (BIM), as well as its transformative power within the construction enterprises. It covers those BIM-related topics relevant for understanding its application for supply chain management in the following chapters.

2.2.1 Understanding the “Digital Evolution”

Construction industry has been facing the era of digital disruption. As any other industry, construction has experienced the gradual process of digital transition by the introduction of CAD (Computer Aided Design) which had at first allowed practitioners to switch from hand-made to digital drawings in 2D format. This disruption brings new opportunities and benefits to the industry actors, but some challenges arise as well within the need for innovative operations of project delivery. In order to understand properly both the benefits and the challenges, an overview of the BIM definitions is presented below.

“A BIM is a digital representation of physical and functional characteristics of a facility. As such it serves as a shared knowledge resource for information about a facility forming a reliable basis

for decisions during its lifecycle from inception onward. “

- National BIM Standard

“A digital representation of the building process used to facilitate the exchange and

interoperability of information in digital format.”

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“BIM is a verb or an adjective phrase to describe tools, processes and technologies that are facilitated by digital, machine-readable documentation about a building, its performance, its

planning, its construction and later its operation.”

- Eastman et al., 2011 From the definitions above, three keywords regarding BIM can be extracted:

digital, information and process.

Interestingly, no definition mentions modelling. Even tough 3D modeling of facilities is enabled with BIM, key letter here is “I” and the information or insight which BIM is able to provide to project actors, through the usage of digital technologies and establishment of new ways of working (processes).

There are various maturity levels which can be implemented starting from 0 to 3, where they have all evolved starting from CAD and 2D drawings. By saying evolved, it is not just a simple evolution passing from 2D drawing to 3D models and objects, but it is a new data environment, able to store various information, as well as new way of working. As Weisheng et al. (2019) note, BIM is “live”, while any of the 2D CAD drawings can be considered quite static. This can be clearly seen in the Figure 4 by representing the evolution of BIM maturity models, initially defined by the UK National Standard.

Figure 4. BIM Maturity levels

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One of the core differences among above shown BIM maturities is the ability to collaborate and create smooth and interoperable workflow, depending on the tools used. Firstly, BIM Level 0 can be considered as a traditional construction practice pre-BIM period, where specifications, quantities and cost estimates are produced manually, from 2D drawings rather than derived from a 3D model. Data exchange can occur in the 2D paper/electronic form. However, main difference between the levels 1, 2 and 3 could be noted as access granted to the models used and level of integration among parties achieved, where Succar (2009) has labelled the levels as Object-based modelling, Model-based collaboration and Network-based integration respectively. The potentials for collaboration within the levels are following:

§ Level 1 - Object-based modelling introduces the concept of object-based modelling in single-disciplinary form in order to support 3D visualization, but without modifiable parametric attributes. Thus, this level is supporting solely the design project lifecycle stage, with no signs of model interchanges and collaborations. § Level 2 - Model-based collaboration enables the creation of BIM federated model,

which allows multidisciplinary project actors to share their parametric-based 3D models within the common file formats such as Industry Foundation Classes (IFCs) as well as working within the Common Data Environment (CDE). Furthermore, this level introduces the other two BIM dimensions, 4D and 5D, by offering interoperability with scheduling software or cost estimation databases respectively. However, usage of certain standards related to files exchange and import/export interoperability is needed to allow the smooth collaboration.

§ Even though majority of the industry actors are currently within Level 1 or 2, the

main goal is reaching Level 3 - Network-based integration and putting the concept of “Open BIM” and Integrated Project Delivery (IPD) into practice. Within Level 3, complete information transparency and real-time modifications sharing is possible, since all the parties can work on a collaborative single project cloud-based model. Example of tools allowing this way of working are Autodesk 360 and Graphisoft BIMX, where each project actor has access to the field relevant to his role on the project. Furthermore, thanks to the power of real-time connection via cloud, data coming from different sensors and devices may be integrated into this environment. Nevertheless, as a prerequisite for its implementation, redefinition of contractual

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relationships and processes, as well as revision of risk-allocation practices is needed (Succar, 2009).

Another classification of BIM practices can be seen from the “dimensional” perspective. When speaking about BIM, most would think of parametric-enabled modeling such as architectural, structural, MEP or other, with the specific geometry data and specifications. Indeed, these three dimensions allow the project team to spot the design gaps at early stages of the project lifecycle, by having the possibility of clash detection and evaluation of different design alternatives.

§ The core value of 3D BIM can be demonstrated with the Figure 5 below (AIA, 2007), which can be considered as the “mainstream” curve of BIM’s role within AEC industry, initially developed by Patrick MacLeamy describing the integrated project delivery. Namely, BIM as a mean for prototyping and visualization allows anticipation of project risks, mainly concerning ability to influence costs before design issues in following phases occur. By early visualizing the discipline-specific models in one BIM model, costs of design changes in early phases are lower than those which may arise during the following project phases when the team and machinery are already on the site and consume financial resources.

Figure 5. Value of 3D BIM

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Speaking of 3D models, another question arises and is related to the Level of Definition or Level of model Detail (LOD) required from each party contributing to the common BIM environment. LODs required from various disciplines (structural, MEP, architectural) rise accordingly to the project lifecycle stage in which a certain deliverable is needed. There is no need for very detailed modelling of each and every part of the future facility, since the process should be efficient and actually ease the assembly on the site. Furthermore, higher level of detail may be required for components ordering or production. Overview of the possible LODs is shown in Figure 6 below.

Figure 6. Overview of different LODs

Source: American Institute of Architects, 2007

Furthermore, by continuing to add dimensions over the 3rd_{, BIM gives the possibility of}

answering to different project needs. Possible dimensions are listed below. § 4D – Adding time

By adding time as a dimension, BIM gives an overview of both spatial and temporal aspects of the project, thus providing all the project actors with the unambiguous logic behind the activities sequencing. By connecting the project schedule with the 3D model of the structure

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and installations, alternatives of activities sequencing and installation plans can be evaluated beforehand.

Moreover, time and space flows of specialized contractors (e.g. mechanical, electrical, plumbing) on site can be visualized and managed more efficiently. Not only human resources can be managed more accurately, but also flows of materials and equipment. This is possible with the visualization of accesses to the site and throughout the site, representation of large equipment and scaffolding locations and their alternatives, as well as material storage areas.

All the above-mentioned functionalities can help optimization of on-site logistics, concerning people and material flows, which will be tackled more in detail within following sections.

§ 5D – Adding cost

The 5th_{dimension allows more accurate and automatized quantity take off and cost}

estimation processes. BIM tools are able to compute the number of specific components, space area and volume, quantities of certain materials, etc. This functionality significantly reduces the probability of human errors and time waste, which may arise when computing these quantities manually from 2D drawings. Nevertheless, mistakes related to the input data can arise when developing the model itself.

Finally, when combining the previous dimensions and LODs, the Table 2 below outlines the requirements of specific LOD in different project lifecycle phases. Certainly, this table differs by project, where the specific requirements shall be specified within the BIM Execution Plan (BEP).

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Project

Phase LOD 100 LOD 200 LOD 300 LOD 400 LOD 500

Design (3D) Non-geometric line, area or volume, not distinguishable by type or material Three-dimension generic object, with material but no layout or location Specific object with dimensions, capacities and space relationships Shop drawing/fabrication with manufacturing and installation-related information As built Scheduling (4D) Total project construction duration Time-scaled, ordered appearance of major activities Time-scaled, ordered appearance of detailed assemblies Fabrication and

assembly details N.A.

Cost Estimation (5D) Conceptual cost estimation Estimated cost based on measurement of generic element Estimated cost based on measurement of specific assembly Committed purchase price of specific assembly at buy out As-built cost Table 2. LOD requirements for certain BIM applications

Source: Adopted from Bedrick, 2008, Weisheng et al., 2019

One perspective which is missing the responsibility of project parties involved and their contribution to BIM CDE. Following chapter tackles this from the perspective of possible BIM information and document flows.

2.2.2 Setting up the BIM process for the Contractor

After having an overview of BIM level boundaries and opportunities they offer to project actors, this section deals with the BIM process flow, mostly from the perspective of the construction contractor and concerning the design and pre-construction project lifecycle phases.

As Sacks et al. (2018) note, the general document and information flows depend on the owner of the first construction model to enter the BIM flow. Initial example (Figure 7) deals with the case when the Contractor develops a construction model from 2D drawing, thus more traditional approach.

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Figure 7. BIM process flow - Starting from 2D drawings

Source: Sacks et al., 2018

This traditional approach can cause inefficiencies when changes in the design model have been made since there is a lack of parametric components and connection between the construction and design model, thus causing time waste in model updates. This limits the potential of the BIM solely on 3D (clash detection, constructability review, visualization) and 4D (visual planning), diminishing the possibility of the 5th_{dimension. This occurs due}

to inability to extract quantities from 3D model in order to support procurement and production control (Sacks et al., 2018).

Figure 8. BIM process flow - Collaborative model

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Another case, more advanced, is the one where the integration of designers’ and contractors’ models into a common collaborative model arises (Figure 8 above). Since the 3D models are produces separately, risk of modifications update is still present as in previous case, while the benefits of higher accuracy appear.

Important thing to emphasize in this case is the nature of the shared model itself, which can be distinguished into 2 cases (Sacks et al., 2018):

1. Single platform model, where multidisciplinary models can be opened and modified in a single BIM platform, thus allowing real-time updates;

2. Federated model, in which modifications to each single multidisciplinary model are done in discipline-specific models and must be imported again into a BIM integration tool (e.g. Autodesk Navisworks Manage, Solibri, VICO Office or other).

The benefits of BIM collaboration can amplify when fabricators are included within a model (Figure 9), especially in the case of providing their own 3D models (not the 2D shop drawings which require additional effort in modelling afterwards). By integrating their 3D models, information such as production details about specific systems and components is provided. AGC (2010) argue that his integration can be considered as a path towards Integrated Project Delivery, thus unlocking the collaboration potential of BIM. Multidisciplinary actors such as architects, designers, contractors, and subcontractors work together from the early phases of the project, which is enabled by a joint contract.

Figure 9. BIM process flow - Including fabricators

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Nevertheless, the usage of specific models and decisions regarding the information and document flows shall be specified within the BIM Execution Plan. By doing so, responsibilities regarding specific deliveries are clearly defined, mostly concerning the time of the delivery, their required LOD as well as software used for model delivery and communication (Hardin and McCool, 2015).

After having an overview of the possible document flows with BIM, another topic, related to interoperability of data coming from various sources will be briefly discussed in the section below.

2.2.3 Interoperability allows collaboration

BIM manager: “All right, so everyone using CAD needs to be saving down DWG s to 2010 for Frank. Make sure you save those in the CAD folder and not the Native folder. We’re going to be using Tekla BIMsight for coordination. If you’re using Revit, then you’ll need to export to IFC for BIMsight but export to DWG for the CAD users. Don’t forget to save down to 2010.”

- Hardin and McCool, 2015 In order to allow BIM to unlock its collaborative potential, interoperability among project actors’ deliverables must be enabled, as well application of certain BIM related standards regarding information and document management. Given the complexity of construction supply chain due to the involvement of many actors which generate data in different formats and software infrastructures, some standards and procedures seem necessary indeed. This complexity leads to inefficiencies in terms of work duplication, time waste for information gathering and poor decision-making based on fragmented or outdated data, due to the lack of the whole picture of the project (Ernst & Young, 2018). Furthermore, given the multiple source of data in construction projects, which is being generatedevery day both from site-related or office-related activities, real time connection among actors is crucial. Thus, Sacks et al. (2018) explain the two most common approaches for achieving easily such interoperability among project actors:

§ Usage of software infrastructure from the same vendor;

§ Usage of software from different vendors which support input/outputs files within the same industry standard.

The potential of the two solutions differ, where the first one allows solid integration among the multidisciplinary design models. As Sacks et al. (2018) notes, in a case when there have

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been some modifications within the architectural model, mechanical model will experience the same changes accordingly. In the second case, objects within the models shall be defined in a proprietary or open-source way (e.g. Industry Foundation Classes) to allow interoperability among various formats of data. This case could seem more realistic, especially since inter-organizational data exchanges are needed (e.g. architectural design has been generated by a consultant external to the Contractor’s enterprise). Given the emergence of new technologies in construction such as IoT and drones or mobile devices, interoperability is needed to capture and share this real-time data from site. In general, these issues can be tackled with APIs (Application Program Interfaces) in the form of plugins as well, by creating well-functioning digital ecosystems.

Even when trying to achieve the 4th_{dimension of BIM, intra-organizational capability}

among the design and planning team shall be established. For example, if structural design has been done in Revit and project schedule in MS Project or Primavera P6, Navisworks or Synchro is needed as an integrative tool to connect this data, while following certain coding principles.

However, practitioners are still lost in this sense, since there is no unique standard specifying which software infrastructure and formats shall be used for data sharing, thus posing additional re-works and costs for the purpose of data visualization, search and exchange. In order to allow smooth data exchange, a clear definition of software infrastructures and data formats which will be in use throughout the project development shall be specified within the BIM Execution Plan.

By tackling the interoperability point, a more comprehensive picture of BIM has been created, mostly in its transformative power within and among the construction enterprises. Accordingly, next section deals with one of the prerequisites for establishing BIM processes – change.

2.2.4 BIM transforms enterprises

“The heart of transformation is the biggest challenge for most people — change.” - Ernst & Young, 2018 Indeed, BIM can offer various advantages, but the road to those applications can be quite long. What is important to be stressed is that BIM shall not be seen only as an application of a specific software (i.e. Revit or Navisworks) inside the company’s premises for obtaining

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short term project-based benefits, but more as a methodology and mindset for future construction supply chain optimization and effective multi actor collaboration within and outside the enterprise boundaries. As noted by McKinsey (2019), success of BIM implementation will ultimately depend on enterprise capability to establish smooth new ways of working. However, in pursuance of this flow, a clear strategy and vision of BIM shall be defined beforehand, with a clear roadmap explaining how to achieve those.

Even though application of BIM has been mainly conducted by the bigger or innovative players within the AEC industry, its more intensive diffusion is expected to come. It is worth mentioning that contractors and reinforcement manufacturers reflect a lower rate of BIM adoption compared to architects and engineers (Aram et al., 2013). Study conducted by Bosch et al. (2017) discovers lack of demand, both external (from clients and partners) and internal (within the enterprise) as a barrier for BIM adoption. Following barriers are concerning high investments needed for setting up hardware and software infrastructure, as well as those related to the lack of competences and user-friendliness of the solutions from the market.

That being said, BIM does really transform enterprises, both on intra- and inter-organizational level. However, the areas of enterprise transformation stemming from BIM implementation can be presented as in Figure 10 below:

Figure 10. Areas of enterprise BIM-based transformation

Source: Hardin and McCool, 2015

Hardin and McCool (2015) label these areas of transformation as: “Three-legged stool as key success factors of BIM.”

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Tools / Technology

Probably, when thinking of BIM implementation, companies initially think of which software infrastructure to adopt. These solutions may be integrated with the existing ones of company’s practices or may require developing radically innovative ones. When speaking about inter-organizational relations, the question of interoperability of data exchange outside company’s borders must be tackled for achieving successful communication, as mentioned in the previous section.

Process

One of the main challenges could be the re-designing of the processes and interactions among the stakeholders. Whichever BIM solution the enterprise decides to implement, it would probably differ from the existing organizational practices and procedures. Therefore, the project actors shall not expect the new tools to be used in the same way as in the previous processes but should rather think of how to establish new workflows.

Behavior

When implementing BIM, traditional mindset and practices should be left aside, since new ways of working are required. This innovative working procedures shall be carefully introduced to the employees via specifically designed training sessions. However, there shall be an internal innovation team, responsible for designing and execution of these trainings, as well as implementation of BIM strategy overall (Aconex Group, 2018). Nevertheless, the top management shall be on board as well. All this has a certain cost, but it shall be offset by value added from BIM adoption in the long term. After all, the people are those who will drive the adoption of BIM, thus employee training costs may exceed those of setting up hardware and software infrastructure (Sacks et al., 2018).

Finally, as anticipated, establishing a clear BIM strategy and roadmap is needed, in which the three above-mentioned factors shall be well defined. As a report by Ernst & Young (2018) notes, a clear digital strategy is an engine for the sound transformation path.

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2.3 Construction Supply Chain

“We will need a new supply chain to deliver our new products to our new set of customers. This supply chain is the bridge between the customer needs of a market segment and the value-added of a product.

If we can’t connect the two, then we have a showstopper.”

- Walker William, 2016 Another relevant part of the research is understanding the construction supply chain itself. This section will firstly tackle the overview of supply chain actors and flows among them, as well as supply chain configurations in terms of diverse material flows. These configurations are strictly related to the quote above. Namely, peculiarity regarding CSC lies in its uniqueness for each and every construction project, because customer (Owner) is the one which dictates the project requirements. Secondly “big blocks” of construction material supply chain will be explained in detail (procurement of building materials / components, production of building materials / components, transportation and logistics, on-site assembly), following the logic of material flows towards the construction site. Finally, core issues and integration trends among supply chain actors will be presented in the final sections.

2.3.1 Construction Supply Chain | Flows and Stakeholders In 1992, Christopher has defined supply chain as:

“The set of a downstream flow of material, an upstream flow of transactions and a bidirectional flow of information.”

From the definition above, we can clearly identify three different flows within this chain: material, financial and information. Later, a supply chain was considered to actually constitute a network rather than a chain, as the multiple organizations that form it, simultaneously generate different and multiple information streams (Christopher, 2005). Therefore, the research on construction supply chain has been and may be conducted from various perspectives, either intra-organizational, inter-organizational or cross-organizational (Vrijhoef and London, 2009). The intra-cross-organizational level concerns material production chains, such as concrete (Aram et al., 2013) and specialized construction operations. Despite material, information and financial flows, CSC is more complex, thus requiring the observation of people, transportation routines and work equipment as well (Cox and Ireland, 2002). In order to observe the inter-organizational SC level, the lack of

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standardization along the supply chain and soft skills, such as trust and leadership and commitment (Kim et al., 2010) shall also be taken into account.

However, in order to understand the nature of the construction supply chains, the definitions of construction projects are presented below:

“An endeavour in which human, material and financial resources are organized in a novel way, to undertake a unique scope of work, of given specification, within constraints of cost and time, so

as to achieve beneficial change defined by quantitative and qualitative objectives.”

- Turner, 1999

“A project is a temporary endeavor undertaken to create a unique product, service, or result.”

- PMBOK The abovementioned novelty can be identified within the construction supply chain as well, due to its unique configuration, unique processes and stakeholders involved, as well as its temporary nature. This could exactly be the point in which CSC differs from the manufacturing one, since the construction supply chain is project based.

Construction Supply Chain Actors

What can be noticed from the definitions above is the configuration of the chain itself, with multiple actors upstream contributing to the final value delivered to the Client downstream. Those actors form the different tiers of construction supply chain (Lundesjö, 2015):

§ Tier 1 companies | Main Contractors and Designers (structural, MEP, architectural) They are usually the closest to the Client and have a contractual relationship; § Tier 2 companies| Subcontractors (specialist/trade contractors or manufacturers)

They usually have a direct contractual relationship with the main contractor/tier 1; § Tier 3 companies | Manufacturers and material distributors

They could form a contractual relationship with tier 2 enterprises (as well as tier 1), in order to supply materials or building components needed for specialist works. As Lundesjö (2015) notes, tier 2 and 3 companies are hired to perform a certain work package for the main contractor. Subcontractors can have a contract for installing specific/specialized construction works, such as mechanical, electrical, piping, roofing, façade, masonry/bricks. However, they may offer additional services such as design, supply, and maintenance of their work package installed. Thus, the final value delivered is

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a direct function of the effective multi actor chain management, since around 75% of the value of the final works stems from works of suppliers and subcontractors (Dubois and Gadde, 2000).

These last two tiers are exactly the spot where the fragmentation effects in the supply chain arise, due to a large number of small, labor intensive companies and competition-based relationships with conflicting inter-organizational culture(Nam & Tatum, 1992; Robson et al., 2014; Dainty et al., 2001). This puts the general contractor in a position of supply chain manager or integrator. Since contractor is usually responsible for the quality of the final product delivered, compliance with certain rules and procedures by subcontractors is needed. As Lundesjö (2015) claims, compliance may be related to management of distribution, deliveries and storage of materials. Since subcontractors are responsible for their own supply chains within this complex network, this poses additional difficulties for the general contractor in managing the flows and diminishes the visibility and effective communication along the distant parties in the chain (e.g. between contractor and building component manufacturer).

Given that the general contractor has a position of a supply chain manager, multiple responsibilities shall be approached carefully. As Council of Supply Chain Management Professionals states:

“Supply chain management encompasses the planning and management of all activities involved in

sourcing, procurement, conversion and all logistics management activities. It also includes coordination and collaboration with channel partners, which can be suppliers,

intermediaries, third party service providers, and customers.”

Therefore, contractor should not think only about managing the information and material flows through different stages of their evolution throughout the project execution but shall consider the management of the stakeholders involved as well.

In order to have an idea about the complexity of information and material flows along the chain and positioning of different supply chain stakeholders, O’Brien et al. (2009) have presented the configuration of CSC, shown in Figure 11 below.

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Figure 11. Overview of the Construction Supply Chain Flows and Actors

Source: O’Brien et al., 2009 Construction Supply Chain Flows

For the sake of simplicity and understanding, information and material flows have been overviewed separately in the following discussion.

§ Information flows

Demonstration of information flows complexity can be seen in the amount of data generated within a large infrastructure project, where around 130 million emails, 55 million documents and 12 million workflows can be exchanged (Aconex Group, 2018). Further complexity concerns also variety and velocity of this data (Figure 12).

Figure 12. The 3 Vs of Construction Project Data

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The 3Vs list from figure above give just a glimpse of the data which could be generated in multiple formats, starting from the 3D design models, through planning and scheduling of activities, to the data gathered on the site during the execution. Due to construction companies’ inability to process this data, 95.5% of data gathered remains unused (Hill, 2017). To tackle this opportunity and exploit the “power of data”, construction industry shall initially employ new ways of working and higher level of collaboration practices, in order to be able to extract the value of the right data (insight) in a right moment and from the right party.

Finally, what is important to be noted is the interconnected nature of these data and their dependence on multiple supply chain actors. Information flows are usually readjusted multiple times since they have to be revised and approved by various actors in order to proceed flowing. As explained by O’Brien et al. (2009), the architect sends drawings to the engineer, who recreates the CAD drawings with engineering information added. After completion of design, the construction manager recreates the drawings to add construction ready details and associated information. This type of information management practices is highly inefficient. Issues stem from the lack of economic incentives for information sharing and the absence of effective tools and methodologies to do so. The consequences are project delays and errors, reflecting in the augmentation of the bullwhip effect (Lee and Billington, 1992) along the chain, where the building product manufacturers experience the highest level of information variability, as the upstream tier suppliers.

§ Material flows

As anticipated by Vrijhoef and Koskela (2000), CSC all the material flowsare converging to the construction site semi-processed or ready to be assembled. Indeed, construction site is an ad-hoc factory where all the material flows are transformed in their desired final form (Cox and Townsend, 1998).

However, different material flows belong to different supply chain configurations. Those chain configurations may depend on the location of material or component production (off or on site), as well as the degree of engineering design required. Therefore, even the concrete supply chain can range from prefabricated elements which are delivered and connected on site (e.g. beams or columns) to delivery of ready-mix concrete which is poured on site. The possible configurations of material supply chain can be seen in the Table 3below.

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Type of building component Description

Made-to-stock components (MTS) § _§ Mass produced components; _{Examples - standard plumbing fixtures,}

dry-wall panels, pipe sections.

Made-to-order components (MTO)

§ Predesigned but only fabricated once an order is placed;

§ Examples - prestressed hollow-core planks, windows, and doors selected from catalogs.

Engineered-to-order components (ETO)

§ Engineering design is required before the manufacturing;

§ Examples - Structural steel frames, precast concrete elements, façades, MEP systems or any other component

customized to fit a specific location and fulfill certain function.

§ Special case - Modular construction with off-site prefabrication.

Table 3. Typical configurations of construction supply chain

Source: Sacks et al., 2018

As Sacks et al. (2018) claim, due to the high level of engineering needed for ETO components, managing this material flow requires tight collaboration among the designers, components producers and those assembling the components on site. However, present material management practices demonstrate a lack of clear responsibilities and real-time communication among the supply chain actors (Perdomo-Rivera, 2004).

2.3.2 “Big blocks” of the Construction Supply Chain

In order to understand the construction supply chain and actors, this chapter will provide an overview of the main phases or “big blocks” through which the materials and related information flow, such as: Procurement of building materials/components, Production of building materials/components, Transportation and Logistics, Construction/On-site assembly. Description and definition for each block is provided, as well as pitfalls of the current practices. Overview is needed to later analyze whether and how those can be tackled by putting BIM into practice.

2.3.2.1 Procurement of building materials / components

Procurement in construction is quite a broad term, while being mainly related to the process of acquiring goods or services necessary for project execution. Charvat (2000) defines

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construction procurement as the process which enables the client to gather the project team and resources needed to translate project idea into reality. Namely, acquisition of services is related to the sourcing and contracting with construction subcontractors and material suppliers, or other parties required to carry out a project. However, scope of the research concerns acquisition of building materials, as it initiates the material flow towards the site (the downstream part of the chain) and is highly bound to the activities of the supply chain management.

Mission of the procurement department can be defined as following:

Acquiring the right products in the right quantity and within the project budget.

Therefore, needs of this department mainly concern a well-developed system for information gathering required for drafting Bills of Quantities (BoQs) for each building material/component, as well as their specifications and quality requirements. Indeed, in this way the department can send the requests for proposals (RFPs) to various components suppliers and evaluate their offers. After the supplier has been chosen based on the established criteria, following step is revising the shop drawings delivered by the suppliers before the production can start.

Procurement of materials is a dynamic process which can last throughout the whole construction phase, thus shall be synchronized and connected with the needs of material installation schedule on site. Special attention shall be given to those materials with long lead times. As Sears et al. (2015) note, purchase orders shall contain the information related to the time and location of material delivery, as well as specific requirements related to their receiving, off-loading, inspecting, storage, handling and installation on site.

However, making mistakes in this dynamic nature is not quite desirable, since it has drawbacks on other parties involved in the project supply chain. As Hadikusumo et al. (2005) claim, traditional material procurement can be quite time-consuming process of extracting material quantities and cost estimates, as well as informing the right supply chain actors when changes in the design occur. If delay or uncertainty is present in these activities, they will strongly affect the production of materials, their installation schedule on site, as well as schedule of other construction activities which they are pushing. Therefore, there is a need of tightly integrating the procurement and on-site logistics functions (Lundesjö, 2015) in order to prevent these types of drawbacks.