Bim Benefits And Challenges

Published Date: 02 Nov 2017

Chapter 2:

2-1 Introduction:

Usually, any construction project reflects the needs of different parties; the owner has his own goals and business plans, the architectural firm seeks to improve the architectural quality, reduce construction risks and improve the construction cost/time efficiency, while the contractor is trying to obtain the highest profit out of the construction process. Those goals need to be managed and harmonized. BIM is a tool, with the potential to achieve those goals.

BIM has been defined in various ways, and has a range of features, which can make the architectural/construction process clearer for all of the project parties. By using a 3D model in any phase of the construction, we can notice what has been achieved in any section of the building, how the construction process will go, and what the expected challenges are. Thus, a key benefit that comes out of using BIM for all the team members is that errors can be easily detected. However, at the same time, BIM can become a big challenge for team members who do not understand how to get the most out of BIM.

This chapter defines BIM, documents how important BIM is to the construction industry, and what are the benefits of using it. Also it discusses various BIM domains and states the overall challenges associated with three domains of BIM.

2-2 BIM features:

Who will benefit by enhancing BIM implementation during the Schematic design and Design Development phases, and subsequently who might apply the results of this study? Smart Market Report shows that architectural, structural, mechanical and plumbing system designers’ -in that order- are the most likely to use BIM. In 2008, architects were the most frequent BIM users with 54% usage. Engineers are slightly behind with 43% of all engineering disciplines using BIM. Electrical engineers lag behind mechanical and structural users (Figure 2-1), because typically electrical design elements are relatively small when compared to bulky structural systems, as well as that electrical coordination or modeling issues are often less critical than other systems (McGraw-Hill 2008).

As shown the expectation for 2009, was that two-thirds of architects would be either heavy or very heavy users, and that engineering was expected to see a 37% increase in usage.

Figure 2-1 BIM Users and Frequency of Modeling Elements with BIM.

Sources: (McGraw-Hill, 2008)

2-3 BIM Advantages:

After more than ten years of BIM use, it is clear that BIM has started to reach a certain level of maturity. Several BIM products are now available to serve various fields such as architecture, structural engineering, MEP engineering, and construction. On the other hand, an increasing number of developers are working on supporting technologies to extend BIM capabilities to cover different aspects of design, planning, and construction. Here, we will classify the major advantages of BIM (Figure 2-2); these advantages will be outlined and classified throughout the S.D and D.D. project phases.

2-3-1 BIM Advantages during the Schematic Design Phase:

Compared to the other project design phases, the BIM advantages in the Schematic Design phase are relatively limited. Some advantages of BIM in the Schematic Design Phase are reviewed.

Model Visualization (2D and 3D):

BIM is a design technology that has replaced CAD drawings with an intelligent 3D computer model that contains structured information for both quantitative information (length, area, volume, and etc.) and qualitative information (material, contents). This may comprise all the design elements such as architectural, structural, electrical, mechanical, and construction process management. Blueprints and 2D information (plans, sections, elevations, etc.) as well as all other construction documentations (list of materials, specifications, reports, and estimates) can be easily generated from the same BIM model.

BIM and Cost estimation:

Although cost estimation typically falls within the scope of work of the cost estimator, and includes material takeoffs, cost estimation is an important feature that helps architects making critical decisions in the early stages of the project. BIM has replaced manual takeoffs, counts, and measurements by generating cost estimations and materials quantification directly from the underlying model, which saves time spent by the estimator on digitizing the architect’s paper drawings, or importing their CAD drawings into a cost estimating package (Autodesk 2007).

2-3-2 BIM Advantages during the Design Development Phase:

According to the state of Wisconsin, department of Administration Division of State Facilities (DADS) report on the current state of BIM technologies and recommendations for implementation, the Design Development phase is one of the most critical phases in the building life cycle. When compared to non-BIM projects, BIM projects are developed to a significantly higher level of details in the Design Development phase, which adds more value and confidence to the design solutions, in addition to less revisions later in the construction documentation phases (The State of Wisconsin June 17 , 2009). In the next section, we will summarize some of the major advantages of BIM during the Design Development Phase.

BIM for Sustainability (BIM and LEED):

Although the intense analysis of a sustainable design proposition usually takes place in the Design Development phase (D.D), the foundation for sustainable design starts from the Schematic Design phase (S.D.) As a collection of software, BIM can support sustainable design through performance analysis. For example, linking BIM to energy analysis applications helps to evaluate the projected use of energy throughout the building life cycle. This integrated approach was not possible by using traditional CAD tools.

Another important feature of BIM applications is their ability to convert the model into non-proprietary formats that contains important design information. Formats such as Green Building XML (gbXML) are supported by various BIM products to enhance the design for LEED compliance and other sustainability goals. Krygiel and Nies indicated that BIM can aid in the following aspects of sustainable design (Krygiel and Nies 2008).

Building Orientation (to select the best building orientation that results in minimum energy costs)

Building Massing (to analyze building shape and optimize the building envelope)

Day-lighting analysis (Data analyses of daylight and shades that result in energy saving)

Water harvesting (to reduce water needs in a building)

Sustainable materials (to reduce material needs and to use recycled materials)

Energy modeling and HVAC design:

To reduce energy needs and analyze renewable energy options such as solar energy, air conditioning/air ventilation, heating, etc. Preparation for these energy performance analyses usually starts after architectural and HVAC design have progressed sufficiently to provide the required information to simulate the building, or at least have the required information or the fundamental design decisions that will be employed to start modeling. HVAC design tools have to import the original building geometry from BIM to create the thermal analysis of the building, and then identify building zones that have one or more spaces, which behave thermodynamically similar. The purpose of this is to adapt the designed HVAC systems to the geometries of the thermal zones, which they serve (Krygiel and Nies 2008).

According to the Smart Market Report, most green project designers (57%) find BIM provides a high level of assistance with their sustainable projects (Figure 2-2). Moreover, as BIM continues to develop, software developers and technology providers are working to enhance BIM to track LEED credits, and to address the sustainable design and construction demands (McGraw-Hill 2008).

Figure 2-2 BIM involvements in Green projects. Source: (McGraw-Hill 2008)

BIM for Mechanical/Plumping Design:

BIM offers a collaborative environment for MEP engineering in which they can work and extract drawings and documents directly from the model. BIM also helps engineers to design and simply modify their design by moving, editing, or dragging design elements directly on the screen. Subsequently all model views, drawing sheets and MEP documents are automatically updated whenever a change is made on the model. This is an important BIM feature, which is known as the "Parametric Change Engine" (Autodesk 2008).

BIM displays the layout of the mechanical system, so that users can get instant feedback on their designs and also can perform many engineering calculations directly in the model. For example, ducts and branch calculations, sizing main and fan sizing are analyzed using American Society of Heating, Refrigerating and Air-conditioning Engineers standards (ASHRAE.) Furthermore, a BIM analysis can automatically suggest a suitable modification for enhancing the design, such as, providing duct and pipe routing solutions between any two points. The software can help the designer find multiple suggested routing paths - allowing him to choose the best solution that improves the design, enabling it to reach its maximum performance and efficiency (Autodesk 2008).

BIM for Electrical Design:

The electrical power and lighting circuits of whole buildings and individual spaces can be easily modeled using BIM. Similar to the mechanical design, the electrical designer can create whole circuits that contain light fixtures, or power devices or equipment in the model, while defining wire types, voltage ranges, distribution systems, and finally connection to a distribution panel. By using the "Built-in electrical calculations engine", "BIM gives the designer instant feedback and calculates the estimated demand loads directly on the model so it helps to prevent overloads and mismatched voltages. BIM also validates the electrical model to make sure that circuit elements/equipment are connected and contribute properly. Then it automatically "wires" those elements and places abbreviations/indications explaining the electrical flow to the main panel (Autodesk 2008).

BIM for Structural Design:

The Structural design process has been improved by using BIM for structural analysis and simulation. The BIM model includes all structural elements of the projects such as beams, girders, columns, panels, etc. Thus, some advanced BIM applications make it possible to simulate the construction process before excavation begins at the job site whilst simultaneously preparing whole project documents. Another important feature of BIM is that it is used as a conflict-resolution tool between the structural and MEP elements (Kymmell 2008).

Driving Model Analysis: The structural analysis model can be derived directly from BIM, which helps save time for analysis preparation.

Driving Data Analysis: Because data and design results are stored in the BIM model, quantity take-offs can be easily and fully automated. Also, analysis models may be derived automatically.

Design changes and time saving: In 2D practice, the issue with design changes is that they are often individually in various places, and in diverse documents, which requires significant time and effort. Design changes in BIM are automatically updated through all documents at once. The 3D model maintains the major benefit of requiring only one local change, which is then automatically applied throughout. This means better design flexibility and less time and money.

Clash detection: In addition to project coordination and construction simulation, BIM offers an important feature called "clash detection" in which conflicts between the structural elements and the MEP components are revealed. The importance of the clash detection feature is that it can discover these conflicts virtually, prior to construction, so they don't affect the bottom line or the project completion date. Obviously, this saves re-work time and construction budget revisions.

BIM and Constructability Analysis:

Constructability analysis is a valuable part of the pre-construction phase, and refers to the assessment of requirements and circumstances pertaining to the construction process, in order to achieve the desired result (i.e., how can the materials be best assembled?). The BIM process in the construction phase applies both to project team management (people-related) and to process management. BIM also continues to be useful for planning purposes that carry over into the construction phase. Some of the key benefits and advantages of BIM are shown in figure 2-3

Material and fabrication

Specification

Direct fabrication

Site layout

Constructability

Final preparation and communication

The Construction Schedule (4D- 5D)

Final Cost estimating

Constructability

Analysis

Schedule and sequence analysis

Assembly sequence/space studies

The construction schedule (4D & 5D)

Cash flow analysis

Shop drawings and Fabrication

Construction Process Management

Post-occupancy evaluation - Facility management

Post Construction

Construction Documents Phase

Post Construction Phase

Architects & Contractors

BIM

Schematic Design Phase

2D/3D documentation

Animation/rendering

Primary Cost estimation

Energy modeling and HVAC design

Sustainable materials

Day lighting analysis

Building massing

Building orientation

Sun shading

Acoustics

Water use

Life cycle analysis

LEED documentation

LEED

Arch

MEP design

Clash detection/interference checking

MEP

Structural design

Clash detection/interference checking

Structural analysis

System co-ordination

Structural design

Design Development Phase

Architects, MEP Engineers, Structural Engineers & Contractors

Figure 2-3 BIM features over the different project phases. Source: researcher

2-4 BIM Domains:

Based on the previously introduced BIM definitions, we can see that although BIM is considered one of the best visualization tools, it is not limited to 3D applications, nor is it a single piece of software. BIM has evolved into much more than a visualization tool; it is a new management process and a collaborative environment. From the researcher's point of view, the best way to describe BIM for this dissertation is as "a process of collaboration and interaction environment between the different project parties." McGraw-Hill Smart 2008 Market Report supported this definition by asserting BIM as, "The process of creating and using digital models for design, construction and/or operations of projects." (McGraw-Hill 2008, pp.17)

In addition, according to the US National Building Information Modeling Standard (US NBIMS), BIM can be defined as; "Building Information Modeling (BIM) is a data based digital representation of functional and physical characteristics of a building from earliest conception to demolition …. BIM, most importantly, is a collaboration of different stakeholders at various phases of the building life cycle to explore, insert, extract, update or modify building information in the BIM database to support and reflect the roles of that stakeholder."(NBIMS-Committee 2010)

This dissertation does not focus on BIM applications or how to better use the software. It discusses the major changes to the existing process model of the traditional architectural project phases and the new methods of data sharing than most CAD architects and engineers are used to. The dissertation also concerns the actions, systems, integrated practice and management processes that are often integral to this change.

BIM is the core management of information and the complex relationships between the social and technical resources that represent the complexity, collaboration, and interrelationships of today's organizations and environments. The focus is on managing projects to get the right information to the right place in the proper time frame. The scope of this research is not to cover every option and all of the currently available or emerging tools and systems, but its main goal is to resolve problems that are caused by inconsistent information, which can be interpreted differently by each BIM player.

By using the 'conceptual clustering' of observable activities and the discovering of roles and interactions in the AEC industry, Michalski has identified three main domains for BIM where information is being exchanged rapidly between these domains: Technology, Process and Policy (Underwood and Isikdag 2010) (Michalski, 1987). Each of these domains has its players, requirements and deliverables. Those players can be individuals, teams, organizations or other groupings (Figure 2-4) (Underwood and Isikdag, 2010, p.66). A complete BIM process model is when these three BIM domains interact within the AECO industry, this forms the whole BIM process model. It is important to understand that failure of the process can be caused by inconsistent and ambiguous information that is being transferred either between the players of the same domain, or between the players of two or three of these domains.

BIM Domains

Figure 2-4 The three main domains of Building Information Modeling (BIM)

Source: (Underwood and Isikdag 2010)(pp.66).

2-4-1 Technology Domain:

The BIM "Technology" domain includes organizations, and software and hardware vendors that focus on the technical aspects of BIM use; the players of this domain could help to directly and indirectly enhance efficiency and profitability of BIM related procedures by developing software, hardware, equipment and networking systems.

2-4-2 Policy Domain:

The "Policy" domain contains a group of players from insurance companies, universities and research centers, etc. who focus on preparing practitioners, delivering research, distributing benefits, allocating risks and minimizing conflicts within the AEC industry (Underwood and Isikdag 2010, p.66). Although the roles of this group don’t appear to be clearly articulated in the current BIM modeling procedures, these roles are vitally important because they lead to changes in the AEC industry.

2-4-3 Process Domain:

The last domain, which is the focus of this dissertation, is the "Process" domain. This domain includes BIM members who handle BIM documents and information. This group includes facility managers, owners, engineers, contractors, architects, etc. This information can be used for ownership and operations of buildings or construction operations (Underwood and Isikdag, 2010, p.66).

2-5 Expected Challenges related to the BIM Domains:

In the early stages of this research, the researcher attempted to classify BIM challenges inside mid-size architectural firms into two types, exogenous and indigenous. The exogenous challenges are mainly the issues that oppose BIM implementation between internal/external entities, such as the communication and contractual issues between architectural team and the contractor. While indigenous challenges are the issues that are to a given firm, for example the communication between the architectural team and BIM manager, or interoperability of files between the different BIM players but within the same organization. It was later found that it is difficult to use this type of classification because of the regular exchange of information, team dynamics and contractual relationships usually occur between -or within- two BIM domains. Thus, it became important to understand that BIM issues cannot be classified within a single domain, but interactions and transfer of knowledge between the players of separate domains are most critical.

Underwood and Isikdag give two cases in which BIM issues could occur between two BIM domains, they state "Case 1: when a BIM deliverable requires input from two or more players or fields. For example, the development and implementation of non-proprietary interoperable schema (like Industry Foundation Classes) necessitates the joint effort of Policy players (researchers) as well as Technology players (software developers). Case 2: when players pertaining to one field generate deliverables classified in another. For example, the Australian Institute of Architects is an industry body' - whose members are Process players (architects) - generating Policy deliverables (guidelines and best practices). (Underwood and Isikdag 2010, p.72).

In this dissertation, the researcher tried to map most of BIM challenges from different literature resources before starting the "on site" data collection phase. Although these challenges may or may not be found in mid-size firms, and need to be uncovered and verified through other verification methods, but mapping of these challenges helped formulate the interview questions, and to identify some important aspects for consideration during the case studies. In the following section we will classify these challenges in relation to the three BIM domains.

2.5.1 Expected Challenges of the Technology Domain:

Expected challenges within the technology domain are represented by BIM software and hardware issues. In this section we will shed light on the most important of these issues:

Interoperability: The current lack of interoperability between the different BIM applications is one of the biggest issues for BIM implementation. Research conducted by Newforma suggests that instead of depending on a single building model, typically some project team members depend on a number of purpose-built models including (Howell 2006):

Conceptual 3D design model (for example, using SketchUp)

Geometric design detailed model (for example, using Bentley Architecture, Structural, and HVAC products)

Finite element analysis structural model (for example, using STAAD)

Steel fabrication Structural model (for example, using Tekla’s Xsteel)

Design coordination model (for example, assembled from multiple sources of design information via NavisWorks)

Construction sequencing and planning model (for example, using Graphisoft’s Virtual Construction solutions)

Hospital Equipment inventory model (for example, using Codebook)

Energy analysis model (for example, using DOE-2 or Energy Plus)

Fire/life safety and egress model (for example, using IES "virtual building environment")

Cost model (for example, using Timberline)

Resource planning model (for example, using Primavera)

As a result, it seems that for a central BIM model it is unlikely that all project members will share a common model; Project teams deal with a collection of different software companies, each of which has their own trusted and preferred software applications for design and analysis. Throughout the different phases of a project life cycle and between different companies, it is very rare that a single product is being used on any one building project.

Forms of visualization: How does one properly view a BIM model? Using a 3-screens projection system by the Immersive Construction Lab while interviewing the project parties (Otto, Messner et al. 2005). If the project parties are to view the model on a single desktop computer, they may miss identifying some of the geometric elements as clearly and quickly as they can when using a large projection display. A feedback of the differences of using information through the desktop/flat screen and the 3-screens projection system could be presented and how it was obtained.

Information exchange: How is BIM information shared? BIM is a set of interactive software exchanging information with various formats. To effectively transfer between different BIM applications, a management strategy must be in place to support those different modeling tools, while not losing the embedded data and important features. This strategy can add complexity to the process.

File size: is one of the main issues and problems of the Technology Domain, and it also affects the Process Domain of BIM. BIM is considered a very specified set of details and large quantities of data that are included for each object in the 3D model, and that is why it generates a huge file size for the whole construction that limits the navigation, rendering, managing, and sharing of the model. In addition, typically one computer can’t manage all of these details, attributes, 3D models and information and be able to share it, and then go one step further and generate a 3D simulation and analysis via a high end up-to-date machines (the architect must have a good understanding of the capabilities of BIM applications to be able to handle those simulations).

Transferring from an old version to a new version: some BIM systems cannot access a newer file version, which arguably is a profit motive for some software vendors. This is a challenge when the firm is using different BIM applications.

2.5.2 Expected Challenges for the Policy Domain:

Although the importance of this domain is not explicitly clear in an office workflow, its role is important because it is a catalyst for the change in the AEC industry. Here we will discuss some issues related to this domain.

AIA policy Issues: An important issue that impacts BIM implementation is concerned with who will be responsible for any inaccuracies in the BIM model. Based on current AIA policies, the architect is only responsible for the design, while the contractor is only responsible for the construction process, while the integrated approach supported by BIM blurs the boundaries of responsibility between the project parties, as a result, risk and liability will become more of a concern (A.I.A 2008).

In September 2008, the AIA tried to foster the adoption of BIM within the design-building industry and at the same time it addressed a new cross-platform solution by announcing the new BIM document E202-2008. This document is not a stand-alone agreement document but must be attached to the AIA agreement of design, construction or services. This document eliminated some of the current limitations in managing the BIM environment inside the office, but still needs to be updated to more specifically address the duties of each party. The document identifies the model ownership, assigns the responsibility for creating or modifying each element of the model at each project phase, controls users downstream of the model, and promotes the interoperability between the users by establishing a standard file format (A.I.A 2008).

Model Copyrights and Legal Changes to BIM Documentation: It is normal for the team members to use proprietary information while creating BIM objects but they have to consider the copyrights of the data and the proprietary nature of the information, which are being used in the BIM model. In order to avoid inhibitions that discourage participants from fully realizing the model potential, this information should be protected.

2.5.3 Expected Challenges for the Process Domain:

The challenges associated with the Process domain can be described briefly as the following.

Communication Difficulties: From the literature review, one of the expected issues that the researcher may find in mid size firms is the lack of early stage of collaboration during the early stages between the different BIM stakeholders. Another aspect of this problem is that the early stage of collaboration between these stakeholders may be initiated through BIM but, as previously mentioned, there may be interoperability and formatting issues. This is because data and information exchange challenges have to be driven by the good understanding of the construction strategy and the methods of transferring this information on time and in the prober format.

Method of collaboration: collaboration between leaders of each team (MEP, Structural, Architectural, etc.) and their members is another significant challenge in mid-size firms. Since information often flows back and forth many times throughout a project, an important issue is to be able to manage the hierarchy between those users inside the firm.

Frequent design changes: ideas might become unrecognizable because of the back and forth interactions between different individuals. Currently, there is no better alternative then to accept this iterative process (Kymmell 2008). Some sources indicate that frequent design changes may consume much of BIM users’ efforts when the workflow is not well planned (Kymmell 2008) (Borzage 2006).

Controlling Data Feed: To be able to know and define who will control the data feed and updating of the model, is very important. It is typically the team leader’s responsibility to manage risk due to wrong data feed and missing information. Accordingly, the AIA document E202-2008 considers a scenario of splitting the responsibility of data feeding between the different architectural office team members. Also, the office team will typically try to identify who is responsible for any errors. This suggests that, there should be only one person responsible for data updating and feeding, which could slow the process and can add more time and cost to the project (A.I.A 2008).

Contractual responsibilities: A "Co-operation mechanism" in the form of defined contact responsibilities between BIM members is often missing. This mechanism should identify the relationships between all the BIM members. It should also encourage the co-operation between the project parties rather than create obstacles and challenges to collaboration. Michael Borzage, professor of construction management at CSU Chico, explains that the weakness of the design-bid-build project delivery approach within the workshops that Construction Simulation Lab offers to the industry, as follows.

"In the traditional design-bid-build project delivery approach, the design and construction portions are deliberately segregated by means of specific contracts with the Owner, the Architect and the Builder. While the reasons for employing this approach may be debated, there can be little disagreement that the owner loses opportunities for added value, and takes on additional risk in at least three important areas. First, the project budget is established early in the process, and serves as an important constraint in the project program."(Borzage 2006)

At the time of bidding, one of the shortcomings with respect to the owner is the "sticker shock" if the bid far exceed the proposed budget. It will be difficult to consider change at this point by identifying and reducing the areas of the project that are generating excessive costs, and the result is typically damage control. The Design-bid-build contractual method is a linear process, which does not support the implementation of BIM.

As previously mentioned, the challenges for BIM implementation usually occur through interactions between the three BIM domains, some of these challenges can impact one or more of the BIM domains simultaneously. Although the research started with mapping these challenges through the literature review, further on-site investigation was needed to determine the impact of these challenges on the BIM related workflow. Figure 2-5 summarizes the challenges associated with the three BIM domains.

Interoperability

Forms of visualization

The method of exchanging information

BIM File size

Transferring from an old version to a new version

Technology

Challenges

Tech Domains

(A) Technology domain components and challenges

Policy Challenges

AIA policy Issues

Model copyrights and legal

changes to BIM documentation

Process Domains

(B) Policy domain components and challenges

Communication Difficulties

Method of collaboration

Frequent design changes

Controlling Data Feed

Preparing for Backup plans

Contractual responsibilities

Risk Shifting

Process Challenges

f Domains

(C) Process domain components and challenges

Figure 2-4 Components and Challenges of BIM domains

2-6 Summary:

This chapter discussed BIM definitions and also describes some of the important features of BIM as categorized through the different project phases. The Chapter discusses the three BIM domains; Technology, Policy and Process as proposed by underwood and Isikdag. Based on these domains, the researcher elaborates the challenges that are currently being faced under each domain. The chapter introduces a general scope of all these issues that will be the foundation for the next phases of the research, but this literature overview will work as a reference for the remainder of the dissertation particularly during the phases of data collection and feedback gathering.