Framework for Work-Space Planning Using Four-Dimensional BIM in Construction Projects

Abstract

Each participant in a building construction project requires a dedicated work space in which to execute their activities. In this environment, inappropriate work-space planning in a construction site causes work-space problems, which results in a loss of productivity, safety hazards, and issues of poor quality. Therefore, the work space should be considered one of the most important resources and constraints to manage at a construction site. However, current construction planning techniques have proven to be insufficient for work-space planning because they do not account for the spatial feature of each activity. To establish a formalized work-space planning process, therefore, this paper categorizes work space by its function and movability and suggests a framework for a work-space planning process that contains five phases, including 4D building information model (BIM) generation, work-space requirement identification, work-space occupation representation, work-space problem identification, and work-space problem resolution. The proposed framework in this paper can improve the accuracy of work-space status representation and work-space problem identification by introducing the work-space occupation concept and the integrated work-space planning process that considers characteristics of activity, work space, and construction plan. In addition, this paper aims to ameliorate the work-space planning process through path analysis and a formalized work-space problem resolution process. To validate the proposed approach, a case project was tested. The result shows the efficiency and effectiveness of the proposed framework on improving the work-space planning process. Based on the result of this study, a project manager will be able to prevent possible work-space problems and their negative effects on project performance by devising a pertinent work-space plan during the preconstruction phase.

Full text

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in
Construction Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Framework for Work-Space Planning Using
Four-Dimensional BIM in Construction Projects
Byungjoo Choi1; Hyun-Soo Lee, Aff.M.ASCE2; Moonseo Park, Aff.M.ASCE3; Yong K. Cho,
Aff.M.ASCE4; and Hyunsoo Kim, S.M.ASCE5
1. Research Assistant, Engineering Research Institute, Seoul National Univ., Kwanak-ro 1, Kwanak-gu, Seoul 151-742, Korea. E-mail:
mill45@snu.ac.kr
2. Professor, Dept. of Architecture and Architectural Engineering, Seoul National Univ., Kwanak-ro 1, Kwanak-gu, Seoul 151-742,
Korea. E-mail: hyunslee@snu.ac.kr
3. Professor, Dept. of Architecture and Architectural Engineering, Seoul National Univ., Kwanak-ro 1, Kwanak-gu, Seoul 151-742, Korea
(corresponding author). E-mail: mspark@snu.ac.kr
4. Associate Professor, School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr., N.W., Atlanta,
GA, 30332. E-mail: yong.cho@ce.gatech.edu
5. Ph.D. Student, Dept. of Architecture and Architectural Engineering, Seoul National Univ., Kwanak-ro 1, Kwanak-gu, Seoul 151-742,
Korea. E-mail: verserk13@naver.com
Abstract
Each participant in a building construction project requires a dedicated work space in which to execute their activities. In
this environment, inappropriate work-space planning in a construction site causes work-space problems, which results in a
loss of productivity, safety hazards, and issues of poor quality. Therefore, the work space should be considered one of the
most important resources and constraints to manage at a construction site. However, current construction planning techniques
have proven to be insufficient for work-space planning because they do not account for the spatial feature of each activity.
To establish a formalized work-space planning process, therefore, this paper categorizes work space by its function and
movability and suggests a framework for a work-space planning process that contains five phases, including 4D building
information model (BIM) generation, work-space requirement identification, work-space occupation representation, work-
space problem identification, and work-space problem resolution. The proposed framework in this paper can improve the
accuracy of work-space status representation and work-space problem identification by introducing the work-space
occupation concept and the integrated work-space planning process that considers characteristics of activity, work space,
and construction plan. In addition, this paper aims to ameliorate the work-space planning process through path analysis and
a formalized work-space problem resolution process. To validate the proposed approach, a case project was tested. The result
shows the efficiency and effectiveness of the proposed framework on improving the work-space planning process. Based on
the result of this study, a project manager will be able to prevent possible work-space problems and their negative effects on
project performance by devising a pertinent work-space plan during the preconstruction phase.
Introduction
One of the distinctive features in a building construction project is limited site space (Bansal 2011; Chua et al. 2010; Said
and El-Rayes 2013). Regarding this constraint, each participant requires specific work space for their resources—such as
laborers, equipment, and materials—to execute their activities (Hammad et al. 2007; Riley and Sanvido 1997; Sadeghpour
et al. 2006). Inappropriate work-space planning leads to work-space problems, resulting in a loss of productivity, safety
hazards, and issues of poor quality (Kaming et al. 1998; Oglesby et al. 1989; Zhang et al. 2007). As a result, a project
manager should consider the work space as one of the consequential resources and constraints to be managed at a
construction site, alongside time, cost, laborer equipment, and material (Akinci et al. 2002a; Chavada et al. 2012; Dawood
and Mallasi 2006; Tommelein and Zouein 1993).
Work space for activity execution is differentiated from other resources. First, the location and size of a work space
occupied by a specific activity at a certain time is influenced by the nature of that activity and its construction plan (Riley
and Sanvido 1995). Second, work-space utilization by each activity shows dynamic changes in three dimensions in
accordance with time flow in a construction project (Akinci et al. 2002b; Tommelein and Zouein 1993; Winch and North

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in
Construction Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
2006). Therefore, an integrated approach embracing the dynamic and complex features of a work space is required for a
desirable work-space plan.
However, current construction planning techniques—such as Gantt chart, network diagram, and critical path method
(CPM)— have limitations in that they cannot account for the spatial feature of each activity and consider only construction
schedules (Chau et al. 2004; Mallasi 2006; Wang et al. 2004). Although the more sophisticated technique of line of balance
(LOB) considers the spatial feature of the activity, it is still insufficient for work-space planning because it assumes that only
one crew is able to occupy each work zone at a time (Akinci et al. 2002a). Owing to the lack of a formalized process for
work-space planning, current work-space planning at the construction site relies on the planner’s intuitive and empirical
knowledge (Akinci et al. 2002c; Sadeghpour et al. 2006). In this circumstance, even for experienced project managers, it is
challenging to completely comprehend the complex and dynamic features of a work space; thus, mangers have experienced
difficulties in proactively preventing work-space problems and their negative effects (Guo 2002; Kelsey et al. 2001; Winch
and North 2006). Moreover, recently increased requirements for a short duration schedule at large and complex projects in
an urban area make it more difficult to design a finework space plan (Hammad et al. 2007; Said and El-Rayes 2013; Wang
et al. 2004).
In recent years, there have been numerous efforts attempting to manage the dynamic and complicated feature of the
building construction process. Among these efforts, a recent achievement in the 4D building information model (BIM),
which links objects in 3D BIM and their corresponding activities in a project schedule, has demonstrated advances in
efficiently handling dynamic and complicated changes during the construction process. This study proposes a formalized
work-space planning process in the 4D BIM environment to proactively handle incidences of work-space problems and to
eliminate waste elements in a construction project.
There are two branches in a space planning–related area: (1) the space scheduling problem that is focused on work space
for activity execution; and (2) the site layout problem that deals with the location and size of temporary facilities at a
construction site (Winch and North 2006). Among these two areas, the space scheduling issue is more suitable for handling
the dynamic and complex features of a work space in a construction process because the site layout is predetermined before
the construction starts. Therefore, this study is focused on the space scheduling problem that deals with activity execution
spaces from a dynamic perspective. In addition, this study assumes that the site layout of the construction project is
established before the work-space planning process starts.
To achieve the purpose, this paper starts with critical reviews of previous related studies that investigate work-space
representation and planning. Then, work space is classified by its function and movability. Based on the critical reviews of
the preliminary studies and work space classification, this study proposes a work-space planning process that contains 4D
BIM generation, work-space requirement identification, work-space occupation representation, work-space problem
identification, and work-space problem resolution. Then, a case study applied with the suggested framework is presented.
Finally, conclusions and recommendations for future research are offered.
Related Research
The purpose of work-space planning in a building construction project is to prevent work-space problems and unnecessary
waste by predicting the work-space utilization status of each participant. Therefore, work-space planning includes a
representation of workspace occupation status, work-space problems identification, and resolution. For an effective work-
space planning process, diverse approaches have been suggested with regard to representing the state of work-space
utilization and managing work-space problems. Table 1 summarizes the major features of previous studies that investigate
the work-space planning process as well as the improvements made by this study. Thabet and Beliveau (1994) suggested a
scheduling method integrating space demand and availability by comparing required space and available space for each
activity in a specific work block. In a follow-up study, Thabet and Beliveau (1994) developed a space-constrained and
resource-constrained scheduling system. Riley and Sanvido (1995) defined 13
construction work-space types and their behavior patterns in multistory building construction projects using site visits,
interviews, and document reviews for 10 case project studies. Riley and Sanvido (1997) developed a methodology for work-
space planning in a construction project through empirical studies on the space planning process. Guo (2002) attempted to
identify work-space conflict in a construction project by manually overlapping work-space demands for each activity on a
project’s CAD drawings, and also proposed criteria for wor- space conflict resolution and a concept for path-space

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in
Construction Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
verification. Akinci et al. (2002a, b) developed a 4D workplanner space generator that automatically generates the work
space for each object through the spatial relationship between objects and the work space defined by the construction method.
Then Akinci et al. (2002c) suggested a method for categorizing and prioritizing identified work-space conflicts. Dawood
Table 1. Review on Related Studies and Improvement in this Study
and Mallasi (2006) developed a PECASO 4D simulator introducing three work-rate distribution types and 12 work execution
patterns to identify work-space conflicts in a construction site. Chavada et al. (2012) suggested a more pragmatic model than
that of previous studies in terms of workspace generation, allocation, and management for each activity in a 4D/5D BIM
environment.
Despite the number of previous studies that have considerably ameliorated the work-space planning process, these studies
have several important limitations regarding work space–utilization status representation, work space problem identification,
and resolution. A majority of previous studies assume that resources for activity execution occupy their required work space
for the entire duration of the activity. However, some activities in a schedule plan could be broken down into several
subactivities, and those activities are completed by executing their subactivities. Instead of the activity occupying the whole
required space during the entire activity duration, subactivities pass through part of the required space several times as they
complete their own task (Riley and Sanvido 1995). In this respect, previous studies’ assumptions fail to achieve an accurate
representation of work-space utilization status. Moreover, previous studies only consider a schedule plan in the workspace
planning process, and they overlook detailed plans to achieve the schedule plan such as an activity execution plan or a
material management plan. Therefore, the location and size of the work space represented in the previous studies are difficult
to update with modifications to these detailed plans. Third, previous studies are not able to reflect the different nature of
workspace types because all types of work spaces are generated by the identical method regardless of the characteristics of
each work-space type. For example, most previous studies identify work spaces for workers and materials through the
identical method although space generation principles for those work spaces are different from one another. This study has
attempted to further improve the findings of previous studies by: (1) differentiating the work-space requirement and work-
space occupation for each activity; (2) integrating characteristics of the work space, activity, and construction plan to
represent work-space occupation; and (3) presenting a formalized procedure for work-space problem resolution.
In this study, the work-space requirement is defined as an entire space that is required for all resources of an activity
during the entire duration of the activity. The work-space occupation is a partial space of the work-space requirement that is
used by workers, materials, or equipment during a unit time period. To execute activity, work-space occupation successively
passes through the work-space requirement during activity duration. As described in Fig. 1, the suggested framework in this
study is able to distinguish between unrealistic and realistic work-space problems in the construction process. If Activity A
and Activity B in Fig. 1 concurrently start, their work-space requirement overlaps, and the previous studies perceive this
Reference
Work-space problem
identification
Operating
environment
Activity execution
progress representation
Integration of
construction plan
and work space
Work-space
problem
resolution
Thabet and Beliveau
(1994)
Guo (2002)
Limited (Congestion)
Yes
CAD
CAD
Workspace occupies
allocated areas for entire
duration of activity
Not mentioned
Manually reflect when
construction plan changes
Not mentioned
Criteria for work-
space conflict
resolution
Akinci et al. (2002b, c)
Yes
4D CAD
Determination of work
space by construction
methods
Prioritization of
work-space conflict
Dawood and Mallasi
(2006)
Yes
4D CAD
12 types of execution
pattern and three types of
work rate
Manually reflect when
construction plan changes
Mentioned conflict
resolution process in
the case study
Chavada et al. (2012)
Yes
4D BIM
Required work space
occupies whole work
space during activity
duration
Enumeration of
possible
solutions for work-
space conflict
This paper
Yes
4D BIM
Differentiated work-
space requirement and
work-space occupation
Integration of activity
execution plan and material
management plan
Formalized procedure
for work-space
conflict resolution

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in
Construction Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
overlap as a work-space conflict. However, the work-space conflict does not actually occur because Activities A and B
occupy the overlapped space on different days. In this study, this phenomenon is defined as an unrealistic work-space
problem.
Work-Space Types
Before suggesting a framework for the work-space planning process, characteristics of a work space should be
comprehended. To integrate the characteristics of a work space with the work-space planning process, this study classified
work space by its function and movability. Classification by its function helps represent the whole work-space requirement
without exception, and classification by movability is useful in identifying the cause of work-space problems and providing
a pertinent resolution strategy for each issue.
Classification by Function
The function of work space explains why a specific work space is required for the activity execution. Among several efforts
to categorize work-space types, Riley and Sanvido (1995) classified work spaces into 13 work-space types by observing the
construction process. Based on Riley and Sanvido’s (1995) classification, this study defines six functional work-space types
by merging the work-space types that perform the same functions, as described in Fig. 2.
Work space in a construction project could be categorized as direct work space or indirect work space depending on its
function. Direct work space is associated with the execution of specific activity in a direct way, and the location and size of
the work space is determined by the geometric features of the related object or construction plan for the activity. Direct work
space includes: (1) object space, which is the area occupied by a building component itself such as a wall, doors, or windows;
(2) working space, which is the area required for crews or equipment to execute a specific activity that contributes physical
changes in a construction project; and (3) storage space, which is the area for storing materials for each activity execution in
a construction project.
Indirect work space has either an indirect relationship with the execution of a specific activity or is associated with the
execution of multiple activities. The location and size of an indirect work space is determined by site layout or predefined
spatial relationships with the direct work space. Indirect work space includes: (1) setup space, which is the area for operating
the overall construction
Fig. 1. Concept of work-space requirement and work-space occupation

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in
Construction Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Fig. 2. Work-space classification structure
project, such as a tower crane and lift car; (2) path space, which is the area required for the movement of resources, such as a laborer or
equipment material; and (3) unavailable space or the unusable area resulting from the protection of established building components or
safety issues caused by certain activity executions. Table 2 summarizes the definition and important attributes of each workspace type.
In this study, to represent the whole work space without exception, requirements of the direct work space are identified by integrating
information about objects, construction methods, and materials. Then, the status of direct work-space occupation is represented by reflecting
the activity execution plan and material management plan. Finally, the status of indirect work-space occupation is represented by referring
to the occupied direct work space and other construction plans. Through these processes, project managers are able to accurately predict the
status of work-space utilization in a construction project and to identify all possible work-space problems in advance.
Classification by Movability
Work-space classification by its attributes contributes to the effective enhancement of the comprehension and utilization of the work-space
characteristics information. Among several work-space attributes, movability is one of the most paramount properties because it assists in
identifying the causes of workspace problems and detects apposite resolution strategies for each issue. Therefore, this study classifies work
space into fixed work space and flexible work space by movability, as indicated in Fig. 2.
Fixed work space is a space that is not able to arbitrarily change its location. For instance, the location of working space is determined
by a spatial relationship with an object defined by a selected construction method. A project manager is not able to change the location of
working space unless the construction method selection changes; thus, working space is categorized as fixed work space. On the other hand,
the location of flexible work space varies by the modification of the construction plan. In general, a project manager plans how to distribute
materials for a specific activity before the activity execution. The material allocation plan could be modified by a project manager’s
managerial decision, and thus the location of storage space for the materials would also change according to the revised plan. In this case,
storage space is categorized as flexible work space. However, not all storage spaces are categorized as flexible work space because the
movability of storage space is determined by the characteristics of the materials. For example, the storage space for plumbing and duct
materials required by mechanical electrical plumbing (MEP) work is flexible work space because those materials are stored at a specific

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
assigned block at a site by the material allocation plan. On the other hand, owing to the difficulty of movement, storage space for brick
materials required for masonry work should be located adjacent to the working space for the activity. Therefore, storage space for a brick
material is categorized as fixed work space.
In direct work space, object space and working space are classified as fixed work space. In the case of storage space, work-space type based
on movability is determined by the characteristics of the materials as previously described. Unavailable space is a type of fixed work space
because working space and object space, which determine the location of the unavailable space, belong to fixed work space. Finally work-
space types by movability for setup space and path space are determined by the flexibility of the construction plan that defines the location
of the work space.
Work-Space Planning Process
Based on the previous work-space classification, this section discusses the work-space planning process that deals with the dynamic and
complicated features of work space in a construction project. Fig. 3 presents a schematic diagram for the overall work-space planning process.
The work-space planning process proposed in this study consists of five phases: (1) 4D BIM, which is able to simulate changes in a
construction project using linkages between objects in 3D BIM and corresponding activities in the project schedule plan, is generated; (2)
the working and storage-space requirements for activities are identified in light of information about construction methods and materials for
activity execution; (3) the status of work-space occupation for all types of work space is represented by reflecting the construction plan,
such as the activity execution plan or material management plan; (4) work-space problems are identified through the spatial clash-detection
algorithm and path analysis process; and (5) a pertinent solution for the identified work-space problem is presented by considering
characteristics of the activity, work space, and construction plan. The details of each phase are discussed in the subsequent sections.
The work-space planning process suggested in this study automatically generates work space and identifies work-space problems when
required information and detailed construction plans are offered. For automated work-space requirement identification, this study builds
required databases for typical types of activities at a construction site (e.g., piping work, ductwork, cable tray work, masonry work, plastering
work, drywall work, waterproofing work, and ceiling work). Meanwhile, a formalized tool for devising a detailed construction plan, which
is necessary for work-space occupation representation, is not sufficient in the construction project.
In this regard, the work-space generation function in the developed framework can be applied to a visualization tool in the decision making
process for those construction plans. Before representing work-space occupation, project managers are able to devise detailed construction
plans based on the identified work-space requirements in their construction project.
Table 2. Functional Work-Space Classification
Type of work space
Definition
Location and size of work space
Generation and expiration of work space
Direct work space
Object space
Areas occupied by building
components such as walls, doors, and
windows
Geometric features of building
components determine the location and
size of the space
Object space is generated at starting point
of linked activity and preserved until
project completion
Working space
Areas required for laborers and
equipment required to execute each
activity on the site
Spatial relationship with corresponding
object defined by construction method
determines the location and size of the space
Working space is generated at the starting
point of the activity and expires at the
ending point of the activity
Storage space
Areas required for materials storage
before consuming them for executing
each activity
Geometric feature of material and quantity
of corresponding activity determine size of
the space; material management plan
determines location of the space
Storage space is generated at the starting
point of the activity and expires at the
ending point of the activity
Indirect work space
Setup space
Areas required to operate overall
construction project (e.g., tower crane,
scaffolding, and lift car)
Temporary facility layout determines the
location and size of the space
Setup space is generated at the starting
point of the independent activity or related
activity and expires at the end point of the
activity
Path space
Areas required for movement of
laborers, equipment, and materials in a
construction project
Construction method for the activity and
geometric feature of materials determines
the minimum path width and height
Defined minimum path width and height is
required during corresponding activity
duration
Unavai-lable space
Areas that are prohibited to use owing
to a safety issue related to the execution
of a specific activity and the protection
of certain building components
Hazardous condition defined by
construction method and object protection
condition determines the location and size
of the space
Unavailable space is preserved during
corresponding activity duration or object
protection duration determined by the
object feature

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
4D BIM Generation
The first task for work-space planning is to generate a 4D BIM for a project. A BIM is a digital representation of the physical and functional
characteristics of a facility and the related project life cycle information; it uses the object-based parametric modeling method [Eastman et
al. 2008; National Institute of Building Sciences (NIBS) 2013]. Each object in BIM is defined by parameters and relationships between
parameters that determine geometric and additional properties of the object. As described in Fig. 3, 4D BIM is able to integrate information
of building components and project schedule by linking between each object in 3D BIM and the corresponding activity in a schedule plan.
4D BIM can represent dynamic geometric changes in a building construction project and is useful in identifying work-space changes in
accordance with the construction process. To represent the status of work-space occupation and to identify work space–related problems,
this study utilized information about activity schedule, object quantity, and the geometric properties of the project that were contained in 4D
BIM.
Work-Space Requirement Identification
The work-space requirement identification phase is a process to identify the entire working and storage-space requirements for the execution
of a specific activity. The detailed process for this phase is shown in Fig. 4.
The construction method and material information databases are necessary for work-space requirement identification. The construction
method database contains information about construction method selection criteria for each activity type and the spatial relationship between
the object and working space that each construction method requires. The material information database includes information about the
physical features of each material, as well as the quantitative relationship between activities and materials. To widen the application of the
suggested framework, this study builds a construction method database (DB) and material information DB for typical finish activities in the
construction project. For example, this study defines typical construction methods for wall finish activities (i.e., standing work, work
platform, rolling scaffolding, scissor lift, suspended platform, and aerial work platform). However, in the case of a project-specific
construction method or material, a project manager should define the
information about those elements according to the established database structure.
To identify the working space requirement, each activity extracted from 4D BIM is classified as an activity type through the work
breakdown structure (WBS). A construction method for each activity is selected from candidate construction methods for the activity type
by considering the corresponding object’s properties in 4D BIM. Afterward, the working space requirement for the activity execution is
identified using the spatial relationship between working space and an object predefined in the construction method database (A in Fig. 4).
Akinci et al. (2002a) suggested a method to generate the work space for each object using the spatial relationship between an object and the
work space, presented in the form of a transformation matrix. Based on this method, the whole requirement of working space for each
activity could be identified. Fig. 5 describes the detailed process of work-space requirement identification for a masonry work activity
example. An object in 4D BIM contains activity properties and physical properties of the object. The activity property (masonry work)
identifies the construction method’s candidates (A in Fig. 5), and physical property (wall height ¼ 4.0 m) determines the definitive
construction method. The rolling scaffolding is selected among the construction method’s candidates for the masonry work because the

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
height of the wall object associated with the activity is more than 3.0 m but less than 5.0 m; thus, the working space requirement of the
activity is identified by repeating the unit work space for the rolling scaffolding work to all of the wall objects. To determine the storage-
space requirement, the quantities of each material needed to perform an activity are calculated by the quantity of the activity in 4D BIM and
the quantitative relationship between the activity and the material in the material information database. The total size of the storage space
for the material is established using geometric information of the materials found in the material information database. Then, the location of
the fixed storage space, which should be adjacent to the working space owing to the nature of the material, is determined using the predefined
spatial relationship between the working space and storage space
Fig. 7. Work-space occupation representation

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Work-Space Occupation Representation
Work-space occupation representation is a phase that describes the state of the work-space utilization for all types of work space by reflecting
the construction plan, such as activity execution plan and material management plan. The detailed process of this stage is delineated in Fig.
7. An activity execution plan is a detailed plan for achieving each activity’s schedule in an activity level. It determines the number of crews
for each activity and each crew’s execution pattern in a construction site. This study adopts Riley and Sanvido’s (1995) workspace pattern
analysis to define the activity execution pattern of each work unit. The material management plan is aimed at providing the necessary
materials for workers when an activity should be performed, including purchasing work, supply planning, and how to handle materials at a
construction site. To represent the workspace occupation, a working space–occupation pattern is identified based on the size of each work
unit defined in the construction method database and the number of work units and the activity execution pattern defined in the activity
execution plan. Then, the velocity of each work unit passing along with the identified pattern is established by the activity quantity and
duration derived from 4D BIM; the working space occupied by work units during a specific time period is represented based on the velocity
(A in Fig. 7).
The state of the storage space occupied by each material is determined by the order interval of each material and material allocation plan.
A material allocation plan is a part of the material management plan that decides how many subunits it will divide the delivered materials
into and how it will lay out those units. First, the total size of the storage space occupation for each material during one order interval is
calculated by dividing the total size of the storage space requirement by the number orders for each material. The number orders for each
material can be calculated by dividing the total duration of the corresponding activity by the order interval of each material. Then, the
location and size of the storage space occupation for delivered materials are represented by referring to the manager’s material allocation
plan. In the case of fixed storage, location is determined using a predefined spatial relationship between storage space and working space (B
in Fig. 7).
Table 3. Detail Criteria for Minimum Size of Path Space
Path
Reference for the straight line size
Laborer
Size of laborer
Work unit
Size of laborer and work unit in construction
method DB
Material distribution
Size of laborer and material package in
material information DB
Material transportation
Size of laborer and material unit in material
information DB

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Object space occupation would be perceived by the result of 4D BIM simulation (C in Fig. 7), and the location and size of the setup space
are determined using the project manager’s site layout (D in Fig. 7). Finally, unavailable space is represented using a spatial relationship
with the object space, which is defined by the protection condition in the object property, or using a spatial relationship with the working
space, which is defined by the hazardous condition in the construction method database (E in Fig. 7).
Work-Space Problem Identification
In this study, the work-space problem is defined as a situation when the work space for conducting an activity is not available. This situation
can occur when different activities are required to occupy a specific space during the same time period or when resources for activity
execution cannot be accessed at their work space because of obstructions created by other work spaces. Therefore, the workspace problem
identification should include detecting not only work-space conflicts but also blocked paths.
Virtual spatial collisions in a 3D model are detected by the algorithm that generates minimized bounding volumes of the objects and
identifies the interference between each bounding volume. A 3D bounding volume is categorized by its shape into bounding spheres (BS),
axis-aligned bounding boxes (AABB), or oriented bounding boxes (OBB), as described in Fig. 8. BS identifies a spatial collision by
comparing the sum of two bounding spheres’ radii and the distance between the centers of two spheres (Talmaki and Kamat 2012). AABB
detects a spatial collision by comparing the minimum and maximum coordinate values of the two bounding boxes that are parallel to their
coordinate axes. OBB generates minimized bounding boxes around objects regardless of the objects’ axis orientations and determines a
spatial collision between the two bounding boxes by identifying the existence of a separating axis (DeLoura et al. 2000; Moller and Haines
2002). AABB is much simpler spatial collision detecting method than OBB because AABB needs six times of comparison calculation,
whereas OBB requires 15 times to detect spatial conflicts. However, OBB is able to detect conflicts more precisely than AABB if the object
in the model is complicated or rotated (Tu and Yu 2009). When most objects at a job site are located parallel to a certain axis in a typical
form, such as a box shape, AABB is the desirable method for identifying a spatial collision, but OBB is more pertinent to the emerging
irregularshaped building project, which contains numerous atypical objects.
In this study, path analysis is defined as a process investigating whether or not available path space for all the resources at a construction
site exists. For path analysis, the wall follower algorithm— which is one of the best-known rules for a maze problem—was adopted in this
study (Madhavan et al. 2009). The wall follower algorithm finds an available path using the following steps: (1) it creates a straight line
from a starting point to a destination point; and (2) when the line encounters an obstacle, the line moves along the surface of the obstacle

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
until it meets the predefined straight line again. As described in Fig. 9, the algorithm determines that a path does not exist when a moving
line spins around at the same place or when the line reaches the boundary of the map (Sedgewick 2001).

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning
Using 4D BIM in Construction Projects.” ASCE Journal of Construction Engineering and
Management, 140(9), 04014041
Fig. 12. Work-space occupation representation for drywall framework
Because diverse paths can be necessary at a construction site, path analysis should be conducted for
every type of path required to execute an activity. Therefore, path analysis should include: (1) a laborer’s
working space; (3) a material allocation path from an entrance to the storage space; and (4) a material
transportation path from a storage space to the working space. The width of a straight line in the wall
follower algorithm, which defines the minimum wideness of the necessary path space, is determined by
the physical feature of the resource for the associated space. The detailed criteria of the minimum size
of path space are described in Table 3.
The project manager can obtain the information of characteristics of activity and work space at the
location where work space problems possibly happen through a systematic approach from the 4D BIM
generation phase to the work space–problem identification phase. In addition to the systematic approach
that helps to get objective information about the work space problem, a managerial approach for the
whole project perspective that considers a relationship with other activities is also required.
Work-Space Problem Resolution
In the work-space problem resolution phase, pertinent strategies are devised for the identified work-
space problems by considering characteristics of an activity, work space, and construction plans. In other
words, the project manager should consider the movability of the work space, the criticality of any
activity, the activity execution plan, and the material management plan to resolve the workspace
problems by the following:
1. Change the location of flexible work space: If there is a flexible work space among conflicted work
spaces, the work-space problem could be resolved by changing the work-space location. When
determining the location of the changed work space, the project manager should consider not only
the location of the conflicted work space but also the location of other work spaces that are occupied
by other activities at the same time. Moreover, the relocation of the path space resulting from the
applied strategy has to be considered to prevent secondary work-space problems.
2. Change the schedule plan for noncritical activity: In the case inwhich every conflicted work space is
a fixed work space, the work-space problems could be resolved by deferring a start date or changing
the duration of the noncritical activity among the problematic activities. In order not to affect the total
duration of the project, the schedule change for noncritical activity should be designed within the
total float of the activity. The continuity of the activity should also be considered.
3. Change the activity construction plan: The activity executionplan and the material management plan
are factors that determine the final status of work-space utilization in the workspace occupation
representation phase. Therefore, the project manager can change the location of the working space
and the related indirect work space through the modification of the activity execution pattern.
Moreover, a work-space problem could be solved by revising the material management plan. When
planning to change the construction plan, the project manager should consider the possible
productivity loss and cost increase caused by the change.
4. Change the schedule plan for critical activity: The work-spaceproblem that cannot be resolved by
Steps 1–3 is resolved by changing a schedule plan for a critical activity. Changing the schedule plan
for the critical activity may cause a project delay, it can prevent further damages caused by negative
project
1
ST
Work Unit
2
nd
Work Unit
3
rd
Work Unit
Workspace Occupation
Status on 1
ST
Day
Workspace Occupation
Status on 2
nd
Day
2
nd
Work Unit
1
ST
Work Unit
3
rd
Work Unit
Workspace Occupation
Status on 3
rd
Day
1
ST
Work Unit
3
rd
Work Unit
2
nd
Work Unit

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
managementissues—such as unnecessary rework, safety hazard, and issues ofpoor quality—owing to theinterference of thework space.
When changing the schedule plan for critical activities, the project manager should examine whether or not the critical path is changed
because of the changed schedule plan.
5. Change the activity logic: Some work-space problems between object space and fixed work space may not be resolved by Steps 1–4.
This type of work space problem occurs when the project manager fails to consider the work space for an activity when determining the
activity sequence. Therefore, this type of work-space problem could be prevented by changing an activity-performing logic with the
consideration of the work space for the activity.
6. Validation of selected resolution strategy: Finally, the validation of the selected work space–problem resolution strategy from the
preceding process is examined by again inputting the strategy into the work-space planning process. In this process, the project manager
can confirm the validity of the selected strategy through the identification of secondary workspace problems by the selected strategy.
Case Study
A research building construction project at Seoul National University in South Korea was examined to validate the proposed framework in
this study. The case project was a one-floor finish work of the 1,850-m2 floor building; this project was to take 90 days and be composed of
23 activities, including vertical piping and finishing. First, 4D BIM was generated with the combination of 3D BIM and an initial construction
schedule.
A required work space for each activity was identified based on the attributes of the object in 4D BIM, construction methods, and materials
for activity execution. The AABB method was used to identify the work-space requirement because most objects in the case project were
located parallel to the project’s local axes in a box shape. Fig. 10 explains an example of the work-space identification for a drywall
framework activity. The rolling scaffolding was determined as a construction method for framing drywall. The entire work-space
requirement of the drywall framework activity was identified by replicating the unit work space for a rolling scaffolding work to all of the
associated objects, as described in Fig. 10.
The project manager in the case project devised an activity execution plan, which divided the entire floor into three work zones—
classroom zone (left), corridor zone (center), and laboratory zone (right)—that consider the schedule plans and quantity of the activity, as
described in Fig. 11. The size of each work unit was the same as the one for the rolling scaffolding (1,800 × 1,200 mm). Based on this
process, a daily occupation status of working space for the activity could be represented as Fig. 12.
Through the process from 4D BIM generation to work-space occupation representation as explained with the example of drywall
framework activity, the work-space occupation status for all 23 activities could be represented. Table 4 shows the detailed information on
work-space occupation representation for several activities of the case project.
After representing the work-space occupation for all activities, possible work-space problems could be identified using spatial collision
detection and path analysis. For example, Fig. 13 displays the spatial conflict between the working spaces for drywall framework activity
and object space for cable tray. This work-space problem could be resolved by changing the schedule of cable tray work execution, which
was originally scheduled for execution before the drywall framework activity for the convenience of table lift movement. By putting the
cable tray work execution after the drywall finish work activity, the productivity was somewhat lowered by the inconvenience of table lift
movement during the cable tray work, but it actually prevented a delay of the project by avoiding more serious rework problems resulting
from work-space interferences.
A total of 37 work space problems were identified by spatial collision detection (31 problems) and path analysis (six problems) from the
case study, and Table 5 summarizes a part of the identified work-space problems. The correct location of a work-space problem was
perceived by the values in the work-space problem location information boxes in Table 5, which indicates the maximum and minimum x-,
y-, and z-coordinate values for the conflicted rectangular space identified by the AABB algorithm. This study improves the precision of
work-space problem identification by including six more work-space problems by path analysis. Moreover, this study also improves the
accuracy of work-space problem identification by removing 40 unrealistic work-space problems in the case project. For example, among
plastering work and drywall finish work, which overlap for 6 days in a schedule plan, 17 workspace conflicts were detected based on the
work-space requirement concept. However, 13 of those conflicts are eliminated by workspace occupation representation suggested in this
study. This implies that the plastering work and the drywall finish work use the same 13 spaces on different dates although both activities
are concurrently executed. In addition, this study completes work-space problem identification by adding one more work-space conflict
identified by path analysis.

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Work-space conflicts between object space and working space most frequently occur (22 times) among total 37 work-space problems. The
working space for a construction activity is frequently interrupted by the object space for an MEP activity, implying that the lack of
communication between managers in different areas leads to an inappropriate work-space plan. In addition, the characteristic of the case
project —research facility requires more MEP systems than common buildings—also affects this result. However, work-space problems
related to unavailable space and setup space do not occur in the case project. This is because one-floor finish work requires relatively little
unavailable space and setup space.
Fig. 13. Work-space problem identification and resolution example
Table 6. Result of Work-Space Problem Resolution in the Case Study
Work-space problem resolution strategy
Number
Rank
Change the location of flexible work space
3
3
Change the schedule plan for noncritical activity
2
4
Change the activity construction plan
15
2
Change the schedule plan for critical activity
—
5
Change the activity logic
17
1
Drywall finish work
Cable tray work
Working space
for
cable tray work
Change the
activity logic
Cable traywork
Drywall framework
Working space
for D/W framework
Object space
for cable Tray
Storage space
for door frame

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Identified work-space problems were resolved by changing the location of storage space for
plastering work and vertical piping work (changing the location of flexible work space), delaying the
start date of the cold-room panel installation (changing the schedule plan for noncritical activity),
modifying the activity execution plan for horizontal piping work and plastering work (changing the
activity construction plan), dividing horizontal duct work into two phases, and changing the sequence
of the cable tray work (changing the activity logic). Table 6 presents how many times each strategy
was applied to solve the identified work-space problems in the case project. Changing the activity
logic strategy is the most frequently adopted solution for the work-space problems in the case project
(17 times). This implies that work space has to be considered from the early stage of scheduling that
determines the sequence of the activities. In addition, changing the activity construction plan is the
second frequent work-space problem resolution strategy in the case project (15 times). This means
that sharing work information with other activities before starting can be effective in preventing
potential work-space problems in a construction project.
The revised schedule plan by the aforementioned work space– problem resolution strategies
indicated a schedule delay because of a productivity decrease and other problems, implying that the
project manager failed to properly consider work space for activity execution during the scheduling
of the project. To complete the project without work-space problems, the project manager therefore
this case project, the project manager planned to implement the crashing strategy, which is a technique
adding additional resources to a critical path activity to catch up when there is a schedule delay, for
one of the critical activities—ceiling work. Although this crashing plan was expected to decrease unit
productivity resulting from additional resource input, it contributed to the improvement of the project
performance by reducing the uncertainty of the project by preventing the work-space problems.
Conclusions
This study suggested a framework for work-space planning process in a 4D BIM environment that
integrates the characteristics of activity, work space, and construction plan. From the case study,
possible work-space problems were successfully identified and the appropriate resolution strategy for
each work-space problem was suggested. The developed framework in this study improved the
accuracy of work-space status prediction and work-space problem identification by introducing the
work-space occupation concept.
The developed framework for the work-space planning process in this study can help the project
manager prepare construction plans that are free of work-space problems. A construction plan
that considers work space can help avoid severe problems—such as rework, a decrease in productivity,
safety hazards, and issues of poor quality—all of which are caused by work-space problems. In
addition, this study’s 4D BIM–based approach for work-space planning shows that the application
scope of BIM can expand into diverse and contextual information that is generated during the
construction process from the simple information that occurs as a consequence of the construction
project.
The framework can also contribute to an effective work-space planning process by using a work-
space occupation representation method that considers construction plan, characteristics of workspace
types, and activity. Moreover, this study can be helpful in ameliorating the work-space planning
process by including the path analysis process that has been overlooked in most of the previous studies.
Finally, the study can contribute to completing the holistic perspective of work-space planning process
by establishing a formalized work-space problem resolution process.
Despite these advantages, this study identified some limitations of the proposed approach. If there
is no abundant data source— such as construction method DB and material information DB—enormous
effort is required to prepare the input data. Also, generating the construction process reflecting BIM,
which is crucial for the suggested framework, requires much effort. Future research will eventually
address these limitations and help improve the construction planning process.

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Acknowledgments
This research was supported by a grant from Super-Tall Building R&D Project (13CHUD-B059157-05) and BIM R&D Program (13AUDP-
C067809-0) funded by the Ministry of Land, Infrastructure, and Transport of the Korean government.
References
Akinci, B., Fischer, M., and Kunz, J. (2002a). “Automated generation of work spaces required by construction activities.” Working Paper No. 58, Center for
Integrated Facility Engineering, Stanford Univ., Stanford, CA.
Akinci, B., Fischer, M, Kunz, J., and Levitt, R. (2002b). “Representing work spaces generically in construction method models.” J. Constr. Eng. Manage.,
10.1061/(ASCE)0733-9364(2002)128:4(296), 296–305.
Akinci, B., Fischer, M., Levitt, R., and Carlson, R. (2002c). “Formalization and automation of time-space conflict analysis.” J. Comput. Civ. Eng.,
10.1061/(ASCE)0887-3801(2002)16:2(124), 124–134.
Bansal, V. (2011). “Use of GIS and topology in the identification and resolution of space conflicts.” J. Comput. Civ. Eng., 10.1061/(ASCE)CP .1943-
5487.0000075, 159–171.
Chau, K. W., Anson, M., and Zhang, J. P. (2004). “Four-dimensional visualization of construction scheduling and site utilization.” J. Constr. Eng. Manage.,
10.1061/(ASCE)0733-9364(2004)130:4(598), 598–606.
Chavada, R., Dawood, N., and Kassem, M. (2012). “Construction workspace management: The development and application of a novel nD planning approach
and tool.” J. Inform. Technol. Constr., 17, 213–236.
Chua, D., Yeoh, K., and Song, Y. (2010). “Quantification of spatial temporal congestion in four-dimensional computer-aided design.” J. Constr. Eng.
Manage., 10.1061/(ASCE)CO.1943-7862.0000166, 641–649.
Dawood, N., and Mallasi, Z. (2006). “Construction workspace planning: Assignment and analysis utilizing 4D visualization technologies.” Comput. Aided
Civ. Infrastruct. Eng., 21(7), 498–513. DeLoura, M. A., et al. (2000). Game programming gems, Charles River Media, Hingham, MA, 502–516.
Eastman, C., Teicholz, P., Sacks, R., and Liston, K. (2008). BIM handbook: A guide to building information modeling for owners, managers, designers,
engineers, and contractors, Wiley, New York, 25–64.
Guo, S. J. (2002). “Identification and resolution of work space conflicts in building construction.” J. Constr. Eng. Manage., 10.1061/(ASCE) 0733-
9364(2002)128:4(287), 287–295.
Hammad, A., Zhang, C., Al-Hussein, M., and Cardinal, G. (2007). “Equipment workspace analysis in infrastructure projects.” Can. J. Civ. Eng., 34(10),
1247–1256.
Kaming, P. F., Holt, G. D., Kometa, S. T., and Olomolaiye, P. O. (1998). “Severity diagnosis of productivity problems—A reality analysis.” Int. J. Project
Manage., 16(2), 107–113.
Kelsey, J., Winch, G., and Penn, A. (2001). Understanding the project planning process: Requirements capture for the virtual construction site, Bartlett
Research, Univ. College London.
Madhavan, R., Tunstel, E. W., and Messina, E. R. (2009). Performance evaluation and benchmarking of intelligent systems, Springer, Boston, MA, 139–
168.
Mallasi, Z. (2006). “Dynamic quantification and analysis of the construction workspace congestion utilising 4D visualisation.” Autom. Constr., 15(5), 640–
655.
Moller, T., and Haines, E. (2002). Real time rendering, 2nd Ed., A. K. Peters, Natick, MA, 631–668.
National Institute of Building Sciences (NIBS). (2013). “National BIM
Standard-United States Version 2.” National BIM Standard-United States Project Committee, Washington, DC. 〈http://www
.nationalbimstandard.org/about.php〉 (Oct. 6, 2013).
Oglesby, C. H., Parker, H. W., and Howell, G. A. (1989). Productivity improvement in construction, McGraw-Hill, New York.
Riley, D. R., and Sanvido, V. E. (1995). “Patterns of construction-space use in multistory buildings.” J. Constr. Eng. Manage., 10.1061/(ASCE) 0733-
9364(1995)121:4(464), 464–473.
Riley, D. R., and Sanvido, V. E. (1997). “Space planning method for multistory building construction.” J. Constr. Eng. Manage., 10.1061/(ASCE) 0733-
9364(1997)123:2(171), 171–180.
Sadeghpour, F., Moselhi, O., and Alkass, S. T. (2006). “Computer-aided site layout planning.” J. Constr. Eng. Manage., 10.1061/(ASCE) 0733-
9364(2006)132:2(143), 143–151.
Said, H., and El-Rayes, K. (2013). “Optimal utilization of interior building spaces for material procurement and storage in congested construction sites.”
Autom. Constr., 31, 292–306.
Sedgewick, R. (2001). “Algorithms in C++ part 5: Graph algorithms.” Chapter 18, External searching, Pearson Education, London, 259–276.
Talmaki, S., and Kamat, V. (2014). “Real-time hybrid virtuality for prevention of excavation related utility strikes.” J. Comput. Civ. Eng., 10.1061/
(ASCE)CP.1943-5487.0000269, 04014001.
Thabet, W. Y., and Beliveau, Y. J. (1994). “Modeling work space to schedule repetitive floors in multistory buildings.” J. Constr. Eng. Manage.,
10.1061/(ASCE)0733-9364(1994)120:1(96), 96–116.

Choi, B., Park, M., Lee, H., Cho, Y., and Lee, H. (2014). “Framework for Workspace Planning Using 4D BIM in Construction
Projects.” ASCE Journal of Construction Engineering and Management, 140(9), 04014041
Tommelein, I. D., and Zouein, P. P. (1993). “Interactive dynamic layout planning.” J. Constr. Eng. Manage., 10.1061/(ASCE)07339364(1993)119:2(266),
266–287.
Tu, C., and Yu, L. (2009). “Research on collision detection algorithm Based on AABB-OBB Bounding Volume.” Proc., First Int. Workshop on Education
Technology and Computer Science, Institute of Electrical and Electronics Engineers (IEEE), New York, 331–333.
Wang, H. J., Zhang, J. P., Chau, K. W., and Anson, M. (2004). “4D dynamic management for construction planning and resource utilization.” Autom. Constr.,
13(5), 575–589.
Winch, G. M., and North, S. (2006). “Critical space analysis.” J. Constr. Eng. Manage., 10.1061/(ASCE)0733-9364(2006)132:5(473), 473–481.
Zhang, C., Hammad, A., Zayed, T. M., Wainer, G., and Pang, H. (2007). “Cell-based representation and analysis of spatial resources in construction
simulation.” Autom. Constr., 16(4), 436–448.