BIM PxP: Knowing the execution plan essentials

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By John Dickinson, PhD, P.Eng., and Paul Woodard, PhD

Construction surveys are suggesting building information modelling (BIM) is experiencing strong, continuing growth in use by stakeholders throughout the industry.1 This means BIM is being employed by more practitioners to document greater project scopes for increasingly diverse purposes over extended project phases.

The good news is, by its very nature, the more BIM is used, the more valuable it becomes. However, along with this increased utility of data, there is an exponentially growing burden of complexity and potential for conflicts and confusion.

Like any other aspect of a project, BIM use needs to be managed to ensure it controls, rather than increases, risk and costs. Perhaps the foremost industry tool to address this is the BIM Project Execution Plan (PxP), also known by various other names, including:

  • BIM Deployment Plan;
  • BIM Execution Plan (BXP, BEP); and
  • Project BIM Plan (PBP).

Its intent is to set out the priorities, policies, and procedures to be used by everyone involved. A poor or incomplete plan can quickly sink a project by failing to establish expectations and by leaving team members’ mechanisms for collaboration to chance.

The PxP does not replace traditional construction contracts and agreements, but rather provides a complementary, formalized, and descriptive record of how BIM will be applied to fulfil the contracted construction project. It is also important to specify in writing which document takes precedence in cases where, despite reasonable efforts or perhaps due to a lack of effort, the contract and the BIM plan differ. Ultimately having everyone agree to a BIM plan greatly increases stakeholder understanding and compliance, which, in turn, reduces risk and promotes project success.

Making a plan capturing all the details that need to be covered can be challenging. This is especially true the first time a project leader tries to craft a PxP. Adopting and modifying an existing BIM plan or protocol (the latter being more commonly publically available as parts of contracts) is one approach, but requires finding a baseline example for sufficiently similar project circumstances. (For more, see “BIM Plan vs. BIM Protocol.”)

Unfortunately, this route can lead planners to not fully consider the unique circumstances, goals, and stakeholder capabilities of the current project. The result may be unnecessary or insufficient BIM requirements, leading to wasted effort and potential misunderstanding.

Alternatively, using a standardized plan development process and available generic templates can greatly reduce the effort required. This also helps ensure the resulting plan specifies BIM logistics sufficient for the project objectives without undue overhead. Reusable templates are particularly valuable for capturing elements such as:

  • references to standards;
  • descriptions of processes;
  • comprehensive lists of roles and responsibilities;
  • modelling requirements for all interactions; and
  • underlying software requirements.

The familiar layout of common templates is also beneficial when seeking buy-in of stakeholders.

Structure of a project execution plan
One of the most widely referenced and accessible BIM planning guides and templates is the National BIM Standard (NBIMS) Project Execution Plan v2.1, which was developed at Penn State University.2 Also referred to as the NBIMS Guide, it has been endorsed by both the Institute for BIM in Canada (IBC) and the buildingSMART Alliance (bSa).

At a generic level, the plan can be broken into three parts as shown in Figure 1:

  • “Uses and Goals;”
  • “Processes and Exchanges;” and
  • “Supporting Infrastructure.”

NBIMS Guide takes a needs-based approach to ensure project goals and stakeholder capabilities are considered before any BIM uses are selected for the project. The team also needs to build a good understanding of the processes that will be followed to achieve the expected BIM uses by identifying tasks and the information (model) flow. Detailed reviews of the required information from models for each task follows based on use and information sources. Finally, the PxP establishes and records the technology, data, and model structure requirements, along with collaboration and quality control procedures.

Uses and goals (NBIMSGuide, Sections 1−3)
Two main elements are considered before BIM uses for a project are selected: business goals and the capabilities (sometimes anticipated) of the project participants. Even basic business goals can be contradictory (e.g. cost versus quality); these must be realistically prioritized for the project. Specific BIM uses can then be identified that support each goal’s achievement (Figure 2).

There is a tendency to be overly optimistic about what can be achieved with BIM. For this reason, analysis is necessary to assess which uses are practical and will deliver tangible benefits for the effort required. This requires considering who is involved, the value and cost of BIM to each stakeholder, and the capability of participants to deliver the resources required. Once this initial work is done, the decisions about goals and uses can be made, and the high-level BIM roles and responsibilities of the participants can be recorded.

Processes and exchanges (NBIMSGuide, Sections 4−5)
Once the project’s BIM uses are selected, the work needs to be broken into tasks and the flow of BIM information must be identified. The goal is to capture how information will be shared, which project participant will create the models (and when), and what specific information will need to be included in the models.

Describing in any detail how to create a process map is beyond this article’s scope, but the process is typically modelled at two levels. Usually a single Level 1 map is created to cover the overall main project tasks and deliverables (Figure 3). Level 2 maps are created for each task identified at Level 1 to examine the roles of individual stakeholders and flow of modelled information in that task (Figure 4).

Attention to detail here is important as these maps define the regular flow of project activities and support the later identification of information requirements—which elements and what level of development—for each model to be shared or exchanged in the project. The NBIMS Guide provides generic process maps that can be customized to particular circumstances if necessary.

Whenever one professional shares modelled information with another, there needs to be an understanding of what information is expected. The information-exchange worksheets (Figure 5) help define the information requirements of the model recipient and identify which model creators will author information elements. It is important to establish these exchanges early, before they become an issue during the project. The results of these worksheets often become an important part of the project contracts.

The information-exchange descriptions usually include specification of the level of development (LOD) definitions being used. (For more, see “Level of Development.”) They also include specific notes on what may or may not be required in the model (e.g. conduit smaller than 38 mm [1.5 in.] in diameter).

Supporting infrastructure (NBIMSGuide, Sections 6−11)
The logistics of a BIM project are typically not very glamorous or complicated, but finalizing them with the team is important for project success. The logistics convert all the decisions made in building the plan into well-defined tasks, processes, or deliverables over a significant range of fundamental operational aspects.

  1. ‘Facility data requirements’ include any client-side BIM deliverable expectations, usually for facility or asset management purposes.
  2. ‘Collaboration procedures’ record planned meeting strategies, exchange procedures (e.g. frequency, file format, naming, location, and servers), access rights, and related roles and responsibilities.
  3. ‘Quality control (QC)’ outlines the requisite model checks, review processes and any tolerances or standards to which the models must adhere.
  4. ‘Technology requirements’ cover software versions and hardware recommendations.
  5. BIM models can become very large so most projects work with multiple distinct, but correlated, models according to disciplines, systems, floors, and/or zones as defined beforehand in the ‘Model Structure’ section.
  6. ‘Project BIM deliverables’ simply serves to itemize the overall expected BIM-related deliverables for the project, when they are due, and their formats.

The most complete plans are created when all the major stakeholders are involved from the beginning, but this is uncommon. There are several possible ways to build a plan without knowing the BIM capabilities or needs of future project participants.

The simplest approach is to plan for future participants to have only the bare minimum of BIM capabilities, although this artificially limits the potential benefits. Alternatively, pre-certifying or qualifying potential partners allows for the selection of more advanced uses of BIM and improved project advantages. The most flexible and perhaps the most demanding approach requires revisiting the plan as stakeholders are engaged to incorporate their capabilities and interests into the project.

The question often arises about whether the PxP is a contract document or a ‘gentlemen’s agreement.’ Sadly, there is no easy answer to this question. However, there is starting to be a general agreement around the idea the BIM protocol (which is typically limited to the logistics of BIM use and the details of the information exchanges) will form part of the contract documents through the use of a contract appendix, addendum, or exhibit as appropriate. In the United States, examples of these documents include Associated General Contractors of America (AGC) ConsensusDocs 301, Building Information Modeling Addendum, and American Institute of Architects (AIA) 202, BIM Protocol.

In this country, the Institute for BIM in Canada is poised to release IBC 100-2103, Contract Appendix, which has been written to suit current standard Canadian contract forms, such as:

  • Canadian Construction Documents Committee (CCDC) 2, 2008 Stipulated Price Contract;
  • Association of Consulting Engineering Companies (ACEC) 31, Engineering Agreement Between Client and Engineer; and
  • Royal Architectural Institute of Canada (RAIC) 6, Canadian Standard Form of Contract for Architectural Services.

It also supports other delivery methods such as design-build and construction management.

The IBC appendix intends to:

  • secure stakeholder agreement to share model content during the project;
  • keep copyright with the model author(s);
  • license content for project use;
  • indemnify authors for model misuse (applications outside limits specified in the appendix); and
  • establish protocols for modelling and model management, while not altering traditional architecture, engineering, contractor, and owner roles.

IBC plans to release the appendix with an accompanying LOD, authorized uses, and a model element table template (IBC 201-2013) with user guide.

Standardized approved contract tools are expected to go a long way toward smoothing one of the major hurdles currently being faced by Canadian BIM adopters. However, project execution planning tools are also needed. IBC has also developed three BIM PxP Toolkits based on the NBIMS Guide that complement the contract documents. The toolkits provide illustrative guides to how information and decisions come together to form a BIM plan for fictional, but realistic, construction project cases.

The different toolkits are designed to cover the use of BIM in different project phases and project structures, including during the Design Development Phase for a design-bid-build project, for facility management (FM) hand-over in a design-build project, and during the Construction Phase in a construction management project. Each toolkit includes several companion documents to make it useful to management as well as practitioners; they include:

  • an overview;
  • executive summary;
  • completed BIM PxP example;
  • detailed illustrated guide describing the creation of the PxP; and
  • reusable templates to allow readers to modify and adopt the PxP for their projects.

As building information modelling sees increased use in construction projects (especially where information will be shared between multiple stakeholders), execution plans will become increasingly important, if not mandatory. While their creation can be time-consuming, these plans help identify and address BIM-related ambiguities that would otherwise only be discovered during project execution.

Templates, guides, and toolkits further help the creation of PxPs. These tools are also maturing as the use of BIM increases, and can bring value and help manage risks on most modern construction projects.


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