4D MODEL BASED ANALYSIS OF RENOVATION PHASING SCHEDULES

A DISSERTATION PROPOSAL SUBMITTED TO THE DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING OF

STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS

FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

Peggy Ho April 5, 2007

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table of contents Abstract ....................................................................................................... 3 1.0 Introduction ............................................................................................. 4

1.1 Motivating Renovation Planning Examples ...................................................... 6 1.1.1 Motivating Example 1: A Courthouse Renovation ......................................... 6 1.1.2 Motivating Example 2: Office Building Renovation (1)................................... 6 1.1.3 Motivating Example 3: Office Building Renovation (2)................................... 6

1.2 Intuition............................................................................................... 7 2.0 Points of Departure .................................................................................... 7

2.1 4D Process Modeling ............................................................................. 7 2.2 Requirements Management ..................................................................... 8 2.3 4D Geometric Clash Detection and BIM-based Design Rule-Checking .................... 8

3.0 Proposed Solution ...................................................................................... 8 3.1 Renovation of a two-story building............................................................... 8 3.2 Occupant Requirements............................................................................ 9 3.3 Construction Requirements .......................................................................10 3.4 Existing and Final Building Configurations .....................................................10 3.5 Renovation Process Model ........................................................................11 3.6 Proposed method to check a phasing schedule................................................12 3.7 Proposed method to represent analysis in 4D .................................................14

4.0 Research Questions and Research Methodology ..................................................15 4.1 Research Questions .............................................................................16 4.2 Perform retrospective case studies ..........................................................16 4.3 Develop the representation and reasoning methods ......................................16 4.4 Develop prototype system to test and refine method.....................................16 4.5 Validate method and prototype system .....................................................17

5.0 Anticipated Contributions to Knowledge and Practice ..........................................17 5.1 Contributions to Knowledge ....................................................................17 5.2 Impact on Practice...............................................................................17 5.3 Broader Impacts on Theory and Practice.....................................................17

6.0 Research Schedule, Anticipated Risks, and Future Research Directions .....................18 6.1 Research Schedule ...............................................................................18 6.2 Anticipated Risks .................................................................................18 6.3 Future Research Directions .....................................................................18

Bibliography .................................................................................................19 Appendix .....................................................................................................20 Appendix .....................................................................................................20

Occupant Requirement Templates....................................................................20 Construction Requirement Template .................................................................20 Space Configuration Template.........................................................................20 Activity Template........................................................................................21 Global Variable Template ..............................................................................21

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Abstract Renovation planners must balance the execution of renovation work with the ongoing operational requirements of the building occupants. These occupant operations have specific requirements that affect the renovation schedule. During the design phase, planners must make trade-offs between satisfying occupant requirements and efficiently executing work when developing the phasing schedule. This problem is made even more challenging because of the changing design, scope, and requirements that are typical during the design phase, causing the planner to re-develop the schedule. It is difficult for planners to understand the benefits and disadvantages of phasing schedules during planning because no formalized metrics or methods exist to “check” the schedule. I propose to define a formal representation of renovation planning elements (i.e., occupant requirements, construction requirements, building configuration, and phase schedules) and to develop reasoning methods that utilize this formal representation to analyze renovation phasing schedules automatically in 4D (3D + time). The research challenge is to develop a representation of the major requirements considered during planning and to develop an analysis method that best captures the key metrics of the phasing schedule using 4D models. The research method involves: performing retrospective case studies; developing a formalized representation and automated reasoning methods; developing a prototype system to test and refine the methods; and validating the methods and prototype system. The purpose of retrospective case studies is to gather information to understand the major requirements, metrics, and limitations of 4D modeling for renovation planning. This drives the development of the representation and reasoning methods. A prototype system will be developed and refined using a gradual progression of cases (e.g., toy problems, intellective experiments, natural experiments). Retrospective validation and charrette testing will be used to validate the representation and reasoning method. The metrics for success in validation will be the ability of planners using my prototype system to analyze and understand a phasing schedule more wuickly and comprehensively than with traditional methods. The scientific contributions of this research are the representation of spatial and temporal requirements that extend beyond existing requirements models to incorporate phasing, and a methodology to automatically check these requirements against a phasing schedule by extending current 4D modeling methods. The practical implications of this research will be a method to enable planners to track phasing requirements, to evaluate the phasing schedule and impacts of changes with respect to project specific requirements more quickly and comprehensively.

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1.0 Introduction The US Census Bureau reported that almost half the volume of construction on commercial buildings in 2002 was attributable to renovation projects (U.S. Census Bureau 2004). Several unique considerations make renovation planning different than planning for new construction. Whiteman and Irwig (1988) note that coordination constraints (i.e., coordination with occupants) and physical constraints (i.e., the existing building) must be considered when planning renovation projects. On renovation projects, trade-offs between the efficient execution of renovation work and ongoing operational requirements of existing occupants must be made. The absence of a consistent set of metrics makes these trade-offs difficult to understand and are not easily observable. Phase planning typically occurs during the design stage of a renovation project. Its purpose is to develop a high-level project phasing schedule that best meets both occupant and construction requirements. A phase schedule describes the relationships between occupants and construction work. Typically, it only shows the high-level construction activities and dates of occupant moves. During phase planning, planners must work with occupants to understand not only requirements for the final design, but also the occupant requirements during renovation (e.g., the best and worst times to move). The problem is further exacerbated because unforeseen changes in requirements, scope, or design affect the phasing schedule, causing planners to re-plan the project. During design, multiple stakeholders are often involved in the design process (Haymaker et al. 2005); this is no different with respect to phase planning. Multiple stakeholders with differing requirements are involved in phase planning, so planners must analyze the schedule from multiple perspectives. Therefore, a major management challenge exists to understand the benefits and disadvantages of a phasing schedule from multiple stakeholder perspectives. Three motivating engineering examples are presented in Section 1.1 to highlight such challenges. Table 1 summarizes the challenges of renovation planning and their effects on project managers (Section 1.1), their respective theoretical limitations (Section 2.0), my proposed research contributions (Section 4.1), and anticipated practice contributions (Section 4.2). While the challenges described below are not only found in renovation projects, the domain of this research is limited to the phase planning during the design stage of building renovation projects.

Table 1. An overview of the challenges of renovation planning and their respective effects on planners, theoretical limitations, research contributions and anticipated practical contributions of my research.

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Challenges in Renovation Planning Effect on Planners Theoretical Limitations Research Contributions Anticipated Practical

Contributions

Challenge 1. Difficult to keep track of requirements

Need to track the requirements of multiple

stakeholders

Only focus on construction OR spatial requirements,

not both

A requirements management model that extends to include

the temporal aspect of requirements

More comprehensive

way to track requirements

Challenge 2. Difficult to evaluate a schedule

Difficult to compare phasing alternatives consistently

and understand trade-offs

4D modeling methods lack the ability to critique project-

specific schedule requirments

A method that extends phasing representation and analysis

methods (i.e., 4D modeling) to evaluate project-specific

requirements

More comprehensive

metrics to evaluate a schedule

Challenge 3. Difficult to evaluate impact of

changes

Need to re-plan phasing schedule every time a requirement changes

4D modeling methods do not show the impact of changing requirements

A method that extends phasing representation and analysis

methods (i.e., 4D modeling) to evaluate project-specific

requirements

More comprehensive

metrics to evaluate the impact of

changes

1.1 Motivating Renovation Planning Examples The following renovation planning examples highlight the different challenges described in Figure 1. Motivating example 1 underscores the difficulty in managing multiple stakeholders and multiple requirements. Motivating example 2 emphasizes the uncertain nature of requirements during phase planning and difficulty in understanding the impact on the schedule. Motivating example 3 shows that no formal metrics exist to evaluate and compare different schedules comprehensively.

1.1.1 Motivating Example 1: A Courthouse Renovation Motivating example 1 involves the phasing of a federal courthouse renovation project. Three separate phase plans were created from different stakeholders: a project consultant, the owner’s regional project team, and the owner’s headquarter project team. The owner wanted to compare each plan to determine the best renovation strategy. Because all plans were presented inconsistently (i.e., a process diagram, a Microsoft Word document, a Microsoft Excel document), I observed that the project consultant had difficulty in comparing the plans. In addition, the owner’s plans (both regional and headquarter) failed to take into account several non-court occupants because the major focus was on the court occupants. A result was insufficient space allocated for non-court occupants, a major flaw resulting in the need for two extra floors on the terrace of the building, and an extended project schedule. As part of my research, I observed the project consultant’s iterative process of developing a phase plan. First, the planner established the requirements and metrics used to develop the phase plan. The metrics for evaluation were total costs (i.e., renovation cost and move costs), project duration, and satisfaction of occupant requirements. This involved understanding the occupant’s future needs, as well as the needs of the building. The scope of the project was then based on these requirements. Second, the planner determined the final locations of each occupant based upon the occupant’s future needs. Finally, after establishing the requirements and building configuration, a phase plan was established that best accommodated both the occupant and construction requirements. In this way, the phase planning was a constant iterative process of changing not only the phasing plan, but also the final location of tenants and/or the scope of building work. Therefore, I observed, it is important for the planner to have all this information easily accessible and changeable to plan the renovation process.

1.1.2 Motivating Example 2: Office Building Renovation (1) Motivating example 2 is based upon the renovation of a 16-story federal office building. The schedule was first changed based upon changing construction requirements (i.e., the addition of a curtain wall to the building façade). The next phasing change occurred due a change in the existing building configuration, when an occupant moved into a vacant floor which was intended to be used as swing space. Although the project manager had several ideas on how to change the schedule, it was not immediately apparent how to revise the existing schedule to accommodate this change.

1.1.3 Motivating Example 3: Office Building Renovation (2) Motivating example 3 is based upon the renovation of a 17-story federal office building that is occupied by 23 tenants. The original plan was first chosen from a set of three alternatives. The metrics for initial evaluation of phasing alternatives were total costs (i.e., renovation cost and move costs), project duration, and number of occupant primary and secondary moves. The original phasing plan, however, changed due to an unforeseen requirement: an additional tenant needed to move into the building. The planner had to reconfigure the building to accommodate

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this change and update the phasing schedule accordingly. The update changed the phasing sequence and/or final location for 10 of the original 23 occupants. Some tenants benefited from this change (e.g., their duration in temporary swing space was reduced), while other tenants were forced out of the building to make room for the additional tenant. No formal or established metrics existed to compare these trade-offs between the original phasing plan and the new one systematically.

1.2 Intuition Phase planning for renovation projects requires four fundamental elements: occupant requirements, construction requirements, representation of the building configuration, and a phase schedule. Phase planning is the process of developing a feasible renovation plan which balances construction and occupant requirements. This inherently requires planners to check requirements against a phasing plan. Based upon the motivating renovation planning examples, it is clear that the checking process needs to be quicker and must provide a more consistent analysis than traditional methods. This can be accomplished through an automatic analysis process. The checking process can be automated because the common denominators for the fundamental elements are spatial and temporal attributes. Spatial and temporal attributes provide the necessary link between requirements and phasing, which will allow planners to evaluate a phasing schedule against a set of requirements. In addition to project-specific requirements, a phasing schedule should also be evaluated with a set of project-independent, global metrics (e.g., move costs, renovation costs, duration, number of occupants with secondary moves). A formalized process would allow planners to manage requirements for phasing and comprehensively evaluate and compare phasing schedules.

2.0 Points of Departure There are three main points of departure for this research: process modeling, requirements management, and 4D model-based analysis methods. Process modeling and 4D model-based analysis methods have focused only on construction activities (and not the occupant), which is insufficient for renovation planning. Requirements management research has mainly been centered on spatial requirements of the finished space, which is also insufficient for occupants who are moving during renovation. The proposed research would extend both of these points of departures to include modeling of temporal requirements and occupant processes.

2.1 4D Process Modeling This research builds upon prior research on representing processes as Component, Action, and Resource (<CAR>) entities (Aalami 1998; Darwiche et al. 1989). Checking requirements against a phasing schedule requires the activities in the schedule and the requirements to be represented as <CAR> entities to allow a computer-interpretable way to understand the transformation of spaces (<C>). This research extends this representation to describe occupant moves and generation of temporary swing spaces. For example, for occupant moves, the <C> representation is elaborated to both the original (“move from”) occupant location to the destination (“move to”) location. This extension enables an automated activity elaboration method to correctly represent these activities in 4D. The challenge with this extension is to ensure that the methodology consistently and accurately elaborates the necessary and required activities.

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2.2 Requirements Management This research builds on the Requirements Model Specification developed by Kiviniemi (2005). His work focuses on how occupant design requirements can be linked to a building product model. In particular, Kiviniemi’s Requirements Model is applicable to this research in the following ways:

1) A requirement model is separate from the product model 2) The concept of Cascading Requirements is used for repetitive requirements 3) It supports the functionalry to compare requirements to design solutions

This proposed research extends upon Kiviniemi’s requirements structure to include temporal requirements needed during the renovation period. The challenge with this extension is to ensure that all major temporal requirements are able to be represented and able to be automatically checked in 4D.

2.3 4D Geometric Clash Detection and BIM-based Design Rule-Checking This research builds up existing model-based requirement checking software (e.g., Solibri Model Checker, and geometric clash detection software such as Navisworks ClashDetective and Timeliner (Navisworks Inc 2006)). Building Information Modeling (BIM)-model checkers have specific static requirements that the BIM model is checked against, but do not have the ability to check temporal requirements. 4D-model checkers can check temporal requirements, but are limited to geometric conflicts and focus solely on construction activities (Akinci et al. 2002; Mallasi 2006; Wang et al. 2004). This research would extend current 4D analysis research by developing a method to input both static and temporal requirements of both occupants and construction and check them against the phasing schedule.

3.0 Proposed Solution The big idea of this research is to define an automated method to check renovation phasing plans against occupant and construction requirements using 4D models. To accomplish this, I first define an ontology for the fundamental renovation elements: 1) occupant requirements, 2) construction requirements, 3) building space configuration, and 4) phasing schedule. Based upon these representations, I then define a method to analyze the phasing schedule with respect to the requirements and global metrics. Finally, I define a representation for visualizing conflicts and unsatisfied requirements in 4D. I plan to develop a prototype system and test the proposed solution to validation my contribution (Section 3.0). A fictitious, but realistic, example of a renovation planning problem and its proposed solution is provided in the following sections. In this example, the planner must evaluate the phasing schedule against a specific set of requirements. Each renovation element (i.e., existing and final building configurations, the occupant and construction requirements, and the phasing schedule) are described as well as the proposed reasoning method and visualization output.

3.1 Renovation of a two-story building This example involves the renovation of a two-story building with five occupants, an elevator system, and lobby. Figure 1 shows the existing and final layout of the building.

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E

F

CD BA

E Lobby

BDA

Lobby

Level 2 Level 1

Existing Configuration

Final Configuration

Level 2 Level 1 Figure 1: Existing and Final Configuration of Building Occupants

3.2 Occupant Requirements As with all phasing problems, each occupant (e.g., a department) has different space and time requirements based upon its business functions. For example, an office that has many people coming in and out should be located near the lobby or an office with very specialized equipment and space functions should be moved only once. I define Occupant Requirement Templates (ORT) to store information about occupant requirements (See Appendix). These requirement templates are extensions from Kiviniemi’s (2005) requirements model. Occupant requirements are organized into two classifications: space and time. Occupant space requirements deal with characteristics of the product model, whereas occupant time requirements deal with characteristics of the occupant move process. For each requirement there is a required value and unit and method to measure the requirement, as well as an effective period. The effective period relates the requirement to when it should be checked in the phasing schedule. Different requirements have different effective periods. For example, requirements may only be required after the renovation (e.g., tenant adjacency), while other requirements must be met throughout the entire renovation process (e.g., security). Each requirement also has a status, which prioritizes the requirements. The status of each requirement can be: established hard, established soft, or tentative. Established hard requirements are those that must be satisfied in the plan, while established soft requirements are requests which may be satisfied only after the satisfaction of established hard requirements. Tentative requirements have the lowest priority, in that they are pending requirements that the planner would like to investigate. Planners may indicate the status of requirements during the planning process to help determine tradeoffs between schedules with respect to the satisfaction of requirements. Table 2 shows the user-entered requirements for the two-story example.

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Table 2. Project-specific occupant requirements for two-story example

Occupant Requirement ID OR-1 OR-2 OR-3 OR-4Occupant A A B B

Requirement Type Functional Adjacency SF Number of Moves Tenant AdjacencyRequirement Rank Hard Hard Hard HardValue Lobby 2250 1 EEffective Period Total Duration End Date Total Duration End Date

Occupant Requirement ID OR-5 OR-6 OR-7Occupant B D ERequirement Type SF Space Attribute Space AttributeRequirement Rank Tentative Hard HardValue 1800 Courtroom SecureEffective Period End Date End Date Total Duration

Project-Specific Occupant Requirements

3.3 Construction Requirements I define Construction Requirement Templates (CRT) to define construction requirements. The CRT is based upon Component and Action (<CA>) entities previously defined in the construction literature (Aalami 1998; Darwiche et al. 1989). Construction requirements define the scope of the specific project and project-independent processes. Construction requirements are also hierarchically ordered with requirements first broken down into space and time. Space requirements indicate how renovation activities relate to spaces (e.g., elevator renovation prohibits elevator access to floors). Time requirements indicate sequencing requirements between renovation activities (e.g., process piping must be done top down). These construction requirements are user-inputted. In the proposed method of analysis, the Scheduling constraints <S> are checked against applicable requirements (e.g., CR-2 and CR-3). Construction requirements also have an effective period and requirement status. Table 3 shows the construction requirements in the two-story example. Table 3. Project-specific construction requirements for two-story example

Construction Requirement ID CR-1 CR-2 CR-3 CR-4Requirement Type Unavailable Predecessor Concurrent Transform

Requirement Status Hard Hard Soft HardComponent 2-5, 1-4 2-1,2-2,2-3,2-4 2-1,2-2,2-3,2-4 Space 1-2Action Renovate Renovate RenovateValue 1-1,1-2,1-3,2-1,2-2,2-3,2-4 1-1,1-2,1-3 CourtroomEffective Period During Activity During Activity During Activity End Date

Project Specific Construction Requirements

3.4 Existing and Final Building Configurations Planners must also define the characteristics of the existing and final building configuration. Because existing spaces may be aggregated or divided into different spaces, unique space IDs must be assigned to the smallest division of space. Space IDs allow for automated tracking of spaces during the checking process. Each space must have the following attributes: an occupant, a function, and a square footage. By assigning attributes to the spaces at both the existing and final

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building configuration, a cross-check of renovation activities can be performed to ensure all renovated spaces have a specific construction activity attached. Figure 2 shows the space IDs for our two story project. Although the original Level 2 West space occupied by Occupant C was originally one large space, the space is broken up into two separate spaces to represent the division of space in the final design. Table 4 shows the attributes of each space in the existing and final building configuration.

2-2

2-4

2-11-21-1

2-5 1-4

1-32-3

Space IDs

Level 2 Level 1 Figure 2: Unique Space IDs are established for each space in the two-story example Table 4. Existing, Final, and Temporary space information for two-story example

Space ID 1-1 1-2 1-3 1-4 2-1 2-2 2-3 2-4 2-5Occupant A B Building Building C D E C BuildingAttributes Office Office Lobby Elevator Office Courtroom Office Office Elevator

Public Secure Secure PublicSF 2250 2250 2700 900 1800 2250 1350 1800 900

Space ID 1-1 1-2 1-3 1-4 2-1 2-2 2-3 2-4 2-5Occupant A D Building Building B E E F BuildinAttributes Office Courtroom Lobby Elevator Office Office Office Office Elevator

Secure Public Secure Secure PublicSF 2250 2250 2700 900 1800 2250 1350 1800 900

Space ID O-1 O-2 O-100Occupant C D FAttributes Office Courtroom Office

SecureSF 3600 2250 2250

Existing

Final

Computer Generated Temp Space

g

3.5 Renovation Process Model Planners must also specify the phasing schedule to analyze. Each phasing activity (both occupant and construction) in the schedule must be specified based upon the Component, Action, Resource, and Sequencing Constraints (<CARS>) activity representation (Aalami 1998). Construction activities have only one component, while occupant move activities have two separate components: a starting space and an ending space. Planners must also specify which occupant is

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moving. It may be possible to automatically populate some attributes in the process model directly from the project schedule. Table 5. Template for user-input of renovation schedule

Activity Activity ID Duration Start Date End DateComponent <C> Activity <A>

Resource <R>

Schedule Constraint (from MSP) <S>

End Space Attribute Start Space End Space Occupant

Two Story Plan 1 1 74 days 3/6/2007 8:00 6/15/2007 17:002

Renovate Elevators 3 10 days 3/6/2007 8:00 3/19/2007 17:00 2-5,1-4 Renovate 1 ElevatorMove out C to Off-site Swing 4 2 days 3/20/2007 8:00 3/21/2007 17:00 3 2-1,2-4 O-1 CMove out D to Off-site Swing 5 2 days 3/20/2007 8:00 3/21/2007 17:00 4SS 2-2 O-2 DConstruct C for temp swing space 6 5 days 3/22/2007 8:00 3/28/2007 17:00 2-1,2-4 TempConstruct 1 5 OfficeMove E in to temp swing 7 2 days 3/29/2007 8:00 3/30/2007 17:00 6 2-3 2-4 ERenovate Level 2 east space 8 10 days 4/2/2007 8:00 4/13/2007 17:00 2-2, 2-3 Build Out 1 7

Office, Secure

Move E into Level 2 East 9 2 days 4/16/2007 8:00 4/17/2007 17:00 8 2-4 2-2,2-3 ERenovate Level 2 west 10 10 days 4/18/2007 8:00 5/1/2007 17:00 2-1,2-4 Build Out 1 9 OfficeMove B into Level 2 West 11 2 days 5/2/2007 8:00 5/3/2007 17:00 10 1-2 2-1 BMove F into Level 2 West 12 2 days 5/2/2007 8:00 5/3/2007 17:00 10 O-100 2-4 FMove A into Level 1 East Space 13 2 days 5/4/2007 8:00 5/7/2007 17:00 12 1-1 1-2 ARenovate Level 1 West Space 14 10 days 5/8/2007 8:00 5/21/2007 17:00 1-1 Build Out 1 13 OfficeMove A back to Level 1 West Space 15 2 days 5/22/2007 8:00 5/23/2007 17:00 14 1-2 1-1 ARenovate Level 1 East Space 16 10 days 5/24/2007 8:00 6/6/2007 17:00 1-2 Build Out 1 15

Courtroom, Secure

Move D from swing to Level 1 Space 17 2 days 6/7/2007 8:00 6/8/2007 17:00 16 O-2 1-2 DRenovate Lobby 18 5 days 6/11/2007 8:00 6/15/2007 17:00 1-3 Renovate 1 17 Lobby

Construction Occpant MoveImported From Microsoft Project

3.6 Proposed method to check a phasing schedule In 4D modeling, the modeling software determines what activities to represent and when to represent them (Aalami 1998). My proposed method builds on these 4D modeling methods. Figure 3 shows the proposed method to check the phasing schedule. At each user-specified interval, my system first determines the state of all spaces in the model during each specified time interval (Table 7). My system then checks which requirements are in effect (Table 6) and measures whether or not they have been satisfied. This automated process provides quick feedback on phasing schedules, which makes the benefits and disadvantages of the schedule readily understood and observable.

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Determine requirements in effect

Use analysis algorithm

Store results in database

For requirements NOT satisfied,Create “Conflict Activities” in phasing schedule

For eachsnapshot date

For each req

Figure 3: Reasoning method to check phasing schedule The satisfaction of requirements is only one type of metric used to evaluate the schedule. During this analysis, global metrics that are separate from project specific requirements will also be measured. These metrics include: swing space utilization, percentage of tenants with primary and secondary moves, move costs, construction costs, and percentages of different requirement types satisfied. Global metrics are measured and updated at each time period. Figure 13 shows the results of these metrics for the two-story example. Table 6. At each time interval, the computer is able to interpret the status of each space (in orange). Spaces in blue highlight changes in the space attributes as a result of renovation activities.

Existing 3/6/07 8:00 3/8/07 8:00 3/10/07 8:00 3/12/07 8:001-1Occupant A A A A AAttributes Office Office Office Office Office

1-2Occupant B B B B BAttributes Office Office Office Office Office

1-3Occupant Building Building Building Building BuildingAttributes Lobby Lobby Lobby Lobby Lobby

1-4Occupant Building Construction Construction Construction ConstructionAttributes Elevator Elevator Elevator Elevator Elevator

Public Public Public Public Public2-1Occupant C C C C CAttributes Office Office Office Office Office

2-2Occupant D D D D DAttributes Courtroom Courtroom Courtroom Courtroom Courtroom

Secure Secure Secure Secure Secure2-3Occupant E E E E EAttributes Office Office Office Office Office

Secure Secure Secure Secure Secure2-4Occupant C C C C CAttributes Office Office Office Office Office

2-5Occupant Building Construction Construction Construction ConstructionAttributes Elevator Elevator Elevator Elevator Elevator

Public Public Public Public Public

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Table 7. Based upon the status of the spaces at each interval, my proposed method is able to determine if a requirement is in effect (in yellow) and if it is satisfied.

Requirement 3/6/2007 8:00 3/8/2007 8:00 3/10/2007 8:00 3/12/2007 8:00 3/14/2007 8:00OR-1 Satisfied Satisfied Satisfied Satisfied SatisfiedOR-2OR-3 0 0 0 0 0OR-4OR-5OR-6OR-7 Satisfied Satisfied Satisfied Satisfied SatisfiedCR-1 Satisfied Satisfied Satisfied Satisfied SatisfiedCR-2 Satisfied Satisfied Satisfied Satisfied SatisfiedCR-3 Satisfied Satisfied Satisfied Satisfied SatisfiedCR-4

3.7 Proposed method to represent analysis in 4D Based upon the unsatisfied requirements identified in the analysis phase, I have developed a method to represent the results in 4D. Since the representation and reasoning process are based upon space and time, the representation of the results can be readily done in 4D. Because conflicts have associated space and time components, this process simply involves adding activities to the process schedule. Figure 11 shows the activities that are added to the phasing schedule. In the 4D analysis output, these spaces are highlighted in red (Figure 12).

Figure 4: Conflicts and unsatisfied requirements are translated into that activities are added to the phasing schedule. As part of this research, I plan to develop a user-interface to allow planners to manage, evaluate, and visualize the phase schedule. Figure 12 shows a mock-up of a user-interface (UI). This user-interface is based upon the UI in Solibri Model Checker (Solibri Inc 2007), a BIM-based requirements checking software. Figure 13 shows a mock-up of an executive dashboard module which would allow project managers to comprehensively understand the benefits and disadvantages of a phasing schedule and enables comparison with other alternatives.

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Figure 5: Based upon the conflict analysis described in Section 1.3.6, users have a way to manage requirements, evaluate, and visually understand the unsatisfied requirements.

RenovationRequirementsInterface

>> Occupant Requirement>> Construction Requirement>> Space>> Activities/Schedule>> Global Values

ResultsOccupant Requirement ID OR-7Occupant ERequirement Type Space AttributeRequirement Rank Hard

Conflicts:OR-7, 3/30-4/15 – Space does not have function “Secure” for Occupant EValue Secure

Effective Period Total Duration

Table 8. An executive dashboard shows a comprehensive set of metrics, visualization of satisfaction of requirements, and enables evaluation of impacts of changes.

Global Variables % of Tentative Occupant RequirementsCost/sf move to temp off-site swing space $15 Previous Phasing Schedule EvaluationsCost/sf move in building $10 Schedule v1Construction Cost/sf $40 Schedule v2

Schedule v3

Satisfaction of Requirements 0% 100%

Total SF-Days (not including Building Common) 532,800 sf-days Occupant RequirementsTotal Vacant SF-Days 37,800 sf-days % Hard Requirements Met 83%Swing space utilization: sf-vacant days/totalsf-days 93% % Soft Requirements Met N/AMax renovation crew required 1 crew % Tentative Requirements Met 100%Total Duration 74 daysConstruction Cost $324,000 Construction RequirementsMove Cost $87,750 % Hard Requirements Met 100%% Occupants with Primary Move 50% % Soft Requirements Met 50%% Occupants with Secondary Move 50% % Tentative Requirements Met N/A

Global MetricsGlobal Metrics

Global DataExecutive Dashboard

0.09%Date

2/10/20072/14/20073/1/2007

Process Metrics

4.0 Research Questions and Research Methodology Based upon my fundamental points of departure, I have developed two research questions and defined a research methodology to carry out this research. The research method involves performing retrospective case studies, developing a computer-interpretable representation and automated reasoning methods, developing a prototype system to test and refine the method, and validating the method and prototype system. These tasks are sequential, concurrent, and iterative throughout the entire research project.

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4.1 Research Questions RQ(1): How can renovation planning elements (i.e., occupant requirements, construction requirements, building configuration, and phasing schedule) be formally represented to enable automatic analysis of phasing schedules with respect to requirements? To address RQ(1), I will develop an ontology to represent renovation planning elements that extend current requirements management and process modeling theory. RQ(2): What method can utilize a formalized representation of renovation planning elements to automatically analyze phasing schedules to enable planners to understand the benefits and disadvantages of a phasing schedule comprehensively? To answer RQ(2), I plan to develop a set of reasoning methods that utilize the ontology from RQ(1) to analyze a phasing schedule automatically and thereby extend current 4D model-based analysis methods. The challenges and metrics for success in answering these questions are detailed in the following research tasks.

4.2 Perform retrospective case studies Retrospective case studies will be performed to understand the types of occupant and construction requirements and schedule evaluation metrics considered during renovation planning. 4D models of renovation projects will be created to understand the current capabilities and limitations of using 4D modeling for renovation planning. The objective of this task is to gather specific metrics and requirements used by planners to develop, manage, and evaluate renovation plans. The information gathered during this period drives the development of the representation and reasoning method described in the next section. The results of my initial motivating retrospective case studies are detailed in Section 1.1.

4.3 Develop the representation and reasoning methods Developing the representation and reasoning methods will involve finding representation and reasoning methods that best capture the information gathered during the retrospective case studies. The representation of the planning elements needs to be generic enough to represent the major occupant and construction requirements and simple enough to be analyzed automatically. The reasoning method developed should be able to utilize the formally represented information and comprehensively analyze and output the results according to the schedule evaluation metrics. The definition of the representation and development of the reasoning methods are closely linked and will require constant iterative cycles between the two tasks. Please see the Appendix for the proposed representation and reasoning method. An example using the proposed method was provided in Section 1.3.

4.4 Develop prototype system to test and refine method Based upon the method developed in Section 3.3, I will build a prototype system to test and refine the proposed method. This system will utilize an extended requirements management and 4D modeling interface to input requirements and visualize the phasing sequence. The development and testing of the prototype system will occur concurrently with the early stages of validation. I will begin by using toy problems and intellective experiments (Thomsen et al. 1999) during this phase.

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4.5 Validate method and prototype system I plan to validate my research based upon elements of Thomsen’s evaluation trajectory. During the early stages of this phase, I plan to use toy problems and intellective experiments to validate the representation and reasoning method. During the latter stages of this phase, I plan to perform retrospective case studies to test my prototype system. I will also conduct a charrette test using at least 4 testers to validate the method and prototype system. Some users will be given the “traditional method” of renovation planning (i.e., paper-based project information and schedule), while others will use my prototype system. Both sets of users will be asked to first evaluate the schedule, and then evaluate impact of a change in requirements. The metrics and measurement methods for validation are: Speed: I will measure the time it takes each user to evaluate the schedule, and to evaluate the

impact of a requirement change. Comprehensiveness: I will measure the comprehensiveness in three ways:

• Representing multiple stakeholders – measure # of stakeholders considered • Evaluating schedules – measure # of metrics • Evaluating impact of a change – measure # of metrics

Generality: I will show that my system can handle different types of facility renovation requirements, can detect conflicts when the inputs change (e.g., requirement changes, alternative phasing schedules).

5.0 Anticipated Contributions to Knowledge and Practice 5.1 Contributions to Knowledge Two anticipated contributions to knowledge stem directly from the proposed research questions: Contribution (1): A formalized representation of renovation planning elements (i.e., occupant requirements, construction requirements, building configuration, and phasing schedule) that extend existing requirements models to include spatial and temporal requirements on renovation projects. This addresses my first research question. Contribution (2): A reasoning process that utilizes a formalized representation of renovation planning elements to enable automatic analysis of renovation phasing schedules. This reasoning process extends current 4D modeling methods that lack the ability to intelligently analyze renovation phasing schedules against requirements and extends current requirements-based BIM constraint checkers. This addresses my second research question.

5.2 Impact on Practice The ability to analyze renovation phasing schedules comprehensively will allow planners to efficiently use 4D modeling during the planning process. Planners will be able to plan interactively using my proposed method and prototype system, leading to faster, better schedules. Planners will also be able to evaluate phasing schedules and understand the trade-offs between them more comprehensively using this approach than with current best practices.

5.3 Broader Impacts on Theory and Practice In addition to the anticipated contributions and impact on practice, this proposed research can have a broader impact on the architecture, engineering, and construction (AEC) industry because

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it directly contributes to an integrated and value-based approach to project delivery in two specific ways. First, it enables the processes of other stakeholders (i.e., the occupant) to be visualized, instead of visualizing construction processes only. Second, a 4D model-based analysis of requirements fosters a process that promotes scheduling from a customer value-based perspective. By analyzing requirements using my proposed methods, a project manager can answer the question “How much value does this renovation schedule deliver to my customers?” and “How can I maximize the value of this renovation schedule for my customers?” instead of “Can I renovate the building with this renovation schedule?”

6.0 Research Schedule, Anticipated Risks, and Future Research Directions 6.1 Research Schedule Figure 14 shows my projected research schedule based upon the tasks described in Section 3.2 – 3.5. I plan to write my dissertation using the three journal paper format. Paper 1 will focus on the representation of the renovation elements for 4D model-based analysis. Paper 2 will focus on the reasoning methods for an automated analysis of phasing schedules. Papers 1 and 2 will include examples from retrospective case studies to show the representation and reasoning methods. Paper 3 will focus on utilizing a 4D model-based analysis to manage requirements and will include results from the charrette tests.

Figure 6: Projected Research Schedule

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Building up research background - 4D modeling on various projects 6/1/2005 6/31/2006

Case Studies (4D modeling and information gathering) 7/1/2006 6/30/2007

Literature Review 1/1/2007 8/31/2007

Qualification exam 4/5/2007 4/5/2007

Develop representation of renovation elements 4/1/2007 12/31/2007

Begin Journal Paper 1: Representation of Renovation Elements 9/1/2007 9/1/2007

Develop reasoning methods for analysis of phasing schedules 7/1/2007 3/31/2008

Begin Journal Paper 2: Reasoning Methods for Phasing Schedules 4/1/2008 4/1/2007

Develop prototype system 4/1/2007 6/30/2008

Testing and Validation 1/1/2008 8/31/2008

Begin Journal Paper 3: Semi-automated analysis for renovation 9/1/2008 9/1/2008

Thesis Defense 9/1/2008 9/1/2008

2006 2007 2008Research Task Start Finish 2005

6.2 Anticipated Risks The major risks for this research are two-fold. The first risk is the ability to assess requirements from the occupants. It may be difficult for the occupant to communicate what requirements they have, especially if they are not familiar with the process of moving in and out of swing space. To mitigate this risk, I will provide examples of requirements from other projects, where the occupants have similar processes (and, therefore, may have similar requirements). The second risk will be the ability to program the algorithms for the prototype system. To mitigate against this risk, I plan to submit a CIFE seed proposal for funding for a programmer.

6.3 Future Research Directions Future extensions of this research will be to develop further both the representation and reasoning process. The representation can be extended to include other types of construction work (e.g., new construction, demolition), other stakeholders (e.g., regulatory) and the associated requirements of additional work processes and stakeholders.

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One limitation of this research is that components are only defined to the space-level. Future research can further detail the representation of components to include finer grained building elements, which can have temporal requirements on them. The reasoning process can be extended to fully automate the analysis process. Future research could involve reasoning about occupant and construction requirements to populate requirements automatically into the analysis. Another future research area would be to develop a method to generate phasing schedules automatically from occupant and construction requirements.

Bibliography Aalami, F. (1998). "Using Method Models to Generate 4D Production Models," Stanford

University, Stanford. Akinci, B., Fischer, M., Kunz, J., and Levitt, R. (2002). "Representing Work Spaces Generically

in Construction Method Models." Journal of Construction Engineering and Management, 128(4), 296-305.

Darwiche, A., Levitt, R., and Hayes-Roth, B. (1989). "OARPLAN: Generating Project Plans by Reasoning about Objects, Actions and Resources." AI EDAM, 2(3), 161-181.

Haymaker, J., Suter, B., Fischer, M., and Kunz, J. (2005). "Narratives: Extensible Distributed Multidisciplinary Parametric Models." ASCE International Conference on Computing in Civil Engineering, ASCE, Cancun, Mexico.

Kiviniemi, A. (2005). "Requirements Management Interface to Building Product Models," Stanford University, Stanford.

Mallasi, Z. (2006). "Dynamic quantification and analysis of the construction workspace congestion utilising 4D visualization." 21st International Symposium on Auotmation and Robotics in Construction, Elsevier, 640-655.

Navisworks Inc. (2006). "Navisworks Timeliner." Scottsdale. Solibri Inc. (2007). "Solibri Model Checker." Helsinki, BIM Analysis Software. Thomsen, J., Levitt, R., Kunz, J., Nass, C., and Fridsma, D. (1999). "A Trajectory for

Validating Computational Emulation Models of Organizations." Journal of Computational & Mathematical Organization Theory, 5(4), 385-401.

U.S. Census Bureau. (2004). "Industrial Building Construction: 2002." 2002 Economic Census. Wang, H. J., Zhang, J. P., Chau, K. W., and Anson, M. (2004). "4D dynamic management for

construction planning and resource utilization." Automation in Construction, 13(5), 575-589.

Whiteman, W., and Irwig, H. (1988). "Disturbance Scheduling Technique for Managing Renovation Work." Journal of Construction Engineering and Management, 114(2), 119-213.

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Appendix

Occupant Requirement Templates Occupant A A A A A A

Requirement Type Number of Moves Move Time Tenant AdjacencyFunctional Adjacency Required SF Required SF

Value "=1" June to November B Lobby 500 1000Unit Count Date Occupant Space Function sf sf

Analysis Algorithm

At each time interval, count number of times occupant has moved

During the dates specified, count the number of moves

During Effective Period, at each time interval, check is A space is adjacent to B space

During Effective Period, at each time interval, check is A space is adjacent to space with "Lobby" function

During Effective Period, at each time interval, check to see if A space has atleast 500 sf

During Effective Period, at each time interval, check to see if A space has atleast 500 sf

Effective Period Total duration Total Duration Final Location Total Duration

Start Date to when A moves to Final Location End Date

Occupant Requirement Templates

Figure 7: Occupant Requirement Templates define the process to measure occupant requirements

Construction Requirement Template

Requirement Type Predecessor Unavailable TransformComponent SP1 Reference Space (SP3) SP1Action Build Out Repair N/AValue Build Out SP2 SP1, SP2 CourtroomUnit <CA> Space Space Function

Analysis Algorithm

Make sure that SP1 BuildOut comes before SP2 BuildOut

During Effective Period, is SP1 or SP2 in use?

Check if SP1 has Space Function Courtroom

Effective Period Total DurationRequirement effective when SP3 has <CA> constraint End Date

Construction Requirement Template

Figure 8: Construction Requirement Templates define the process to measure construction requirements

Space Configuration Template

Space ID SP1 SP2 SP1 SP2 SP3 SP4 SP5Occupant A B B A C A BFunction Office Courtroom Courtroom Office Office Office CourtroomSF 5000 5000 5000 5000 1000 5000 5000

Space Configuration Template

Existing Final Temporary Off-siteUser-input Computer generated

Figure 9: Template to enter building configuration information

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Activity Template

Construction MovesActivity ID 5 Activity ID 7Component SP1 Start Component SP1Activity BuildOut End Component SP3Resource 1 crew Occupant ASequence Constraint 4 Start Date 5/20/2007End Space Function Courtroom End Date 5/25/2007Start Date 6/1/2007End Date 10/1/2007

Renovation Schedule Template

Figure 10: Template for user-input of renovation schedule

Global Variable Template

Global VariablesCost/sf move to temp off-site swing space $15Cost/sf move in building $10Renovation/sf $40

Global MetricsSwing space utilization: sf-vacant days/totalsf-daysMax renovation crew required

Total DurationTotal Cost% Hard Requirements Met% Soft Requirements Met% Tentative Requirements Met% Tenants move more than once

Global Data

Figure 11: Template for global data and metrics used for entire project

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