BIM Level 2

Level 2 Maturity is defined in the Department for Business, Innovation and Skill’s BIM Working Party strategy paper as:

‘A managed 3D environment held in separate discipline “BIM” tools with data attached. Commercial data will be managed by enterprise resource planning software and integrated by proprietary interfaces or bespoke middleware. This level of BIM may utilise 4D construction sequencing and/or 5D cost information.’¹

We shall clarify the meaning of 4D, 5D and other dimensions of BIM in Chapter 5. However, at this stage, the BIM Level 2 mandate establishes the importance of delivering information from the model(s) in accordance with predefined requirements.

PAS-1192

The PAS-1192 documentation is a suite of specifications introduced as a consequence of the Government’s BIM Strategy. Together, they provide guidance for collaborative project/asset information management through BIM. PAS-1192-2 describes the generic BIM workflows that should be adapted to the distinctive design, construction and asset management requirements of specific building projects.

That strategy was informed by the commissioned BIM Working Party strategy paper issued earlier that year, which established the importance of two overarching strategic actions: Client ‘Push’ and (in response to this) Project Team ‘Pull.’²

Reviewing the Business impact of EIRs

There are significant responsibilities involved in meeting the expectations contained in EIRs for information delivery via BIM. For each requirement, the BIM Manager should assess the contractual scope and the risks incurred by the specified information requirements, and devise a careful plan to mitigate them. In terms of the EIRs that accompany bid documentation, it is invaluable to conduct a comprehensive risk assessment that draws upon the experience and insight of the BIM Manager. A checklist like the one above is a useful tool when assessing this risk.

In respect of question 11, an important step would be for the assigned Project Manager and the person assuming the BIM management role to invite the client’s BIM Technical Adviser to explain the purpose of any particularly challenging requirements, with a view to achieving an acceptable compromise.

Understanding the risks incurred by these requirements, finding the compromises that will mitigate them, and persuading the client to approve such amendments are all key aspects of pre-contract BIM management. They are at least as important as the technical requirements that you will specify, should you recruit a person to perform this role.

BEP – 1 – The Standard Method and Procedure

The Standard Method and Procedure should encompass proposals for:

• Roles and responsibilities, in particular the overall responsibility for BIM coordination and information delivery from the full range of design and construction disciplines.
• A secure online repository of shared project models and data known as the Common Data Environment (defined in PAS-1192-2 as ‘a single source of information for any given project, used to collect, manage and disseminate all relevant approved project documents for multi-disciplinary teams in a managed process).’
• Compatible software applications for model development and file formats required for information exchange.
• Common conventions for file and folder naming that would make it easy to distinguish the originator, discipline, zone, level, purpose and revision status assigned to each model.
• The means by which the Common Data Environment will logically segregate work-in-progress models from shared data and client-approved construction documentation.

It’s important to note that the primary purpose of BIM Level 2 is coordinated information management and not just the management of coordinated drawing production.

BEP – 2 – Supplier Building information Management, it and Resource Assessment

In response to the BIM-related aspects of any bid documentation, the BIM Manager will also be expected to complete a number of PAS-1192-related assessment forms on behalf of his/her firm. The responses on these forms should provide evidence-based confirmation of:

• Understanding of BIM and its applicability to the normative design/construction collaboration processes of the firm
• The design and construction functions for which BIM has been utilised and the successful project outcomes attributed to it
• IT, training/assessment and management provisions in place for project delivery in BIM
• Current processes for vetting work against CAD/BIM standards
• The extent to which the firm’s CAD/BIM Standards are aligned with national BIM standards
• Successful implementations of BIM on key projects.

These are probing questions, but answering them candidly will go a long way towards ascertaining your company’s BIM Level 2 readiness.

BEP – 3 – Project Goals for Collaboration and Information Modelling

Project goals represent the outcomes by which we measure the success of using BIM.

Let’s return to the Government Construction Strategy and remind ourselves of the key benefits that it cites for adopting BIM:

• Comparative ease in evaluating the implications of alternative design proposals
• Elimination of coordination errors and subsequent expensive change because projects are modelled in three dimension.
• Elimination of unnecessary intermediaries by linking design to manufacture by direct control of machine tools
• Establishing a proper basis for asset management subsequent to construction.

In a fully collaborative 3D environment, BIM Level 2 involves the extraction of the commercial data that has been cross-referenced to 3D elements located in the various model contributions of each discipline. In short, once the appropriate kind of data is attached to the model elements, the client should be able to use proprietary tools to extract further information from them; this information can then be analysed in order to assess and even improve project outcomes.

In line with these kinds of benefits, project goals should be described in accordance with the EIRs. Here are a few examples:

• ‘In conjunction with other consultants, BIM will be used to facilitate the client’s evaluation of design alternatives by providing 3D visualisations of different proposals with associated cost estimates, area schedules and energy usage projections.’
• ‘BIM will be used to significantly reduce the cost of design re-work by using collaborative model walkthroughs, whereby all design issues raised by consultants will be mapped to specific elements and named views of the model. Potential conflicts will be resolved by using the combined 3D model to coordinate a solution that is agreeable to all relevant parties.’
• ‘BIM will be used to make the construction process faster and safer by developing and reviewing construction sequence animations and Design for Manufacture and Assembly proposals developed from the 3D models.’
• ‘At handover, BIM will be used to provide a comprehensive verified set of asset information in a format compatible with the client’s FM system.’

Of course, these goals may incur significant immediate additional costs that will be offset by consequent savings and benefits realised later on in the project lifecycle. These need to be negotiated against the contractual scope of project participants.

BEP – 4 – Major Project Milestones Consistent with the Project Programme

The table below shows the types of deliverables that would be derived from BIM for client review at the end of each project stage.

BEP – 5 – Project Information Model (PIM) Deliverable Strategy

As a deliverable, the Project Information Model integrates actionable project data and documentation with progressively more detailed elements in the 3D model.

In its document entitled Outline Scope of Services for the Role of information Management⁷, the Construction Industry Council (CIC) refers to this PIM deliverables strategy as the Project Information Plan, calling it ‘the plan for the structure and management and exchange of information from the Project Team in the Information Model and the related processes and procedures.’

Table 2.3 The key deliverables derived from BIM for each project stage

It adds that the plan should contain:

• a) Responsibility for provision of information at each Stage
• b) Level of detail/information required for specific Project Outputs e.g. Planning, Procurement, FM Procurement
• c) Information structure across roles e.g. software platforms (all levels of supply chain) and data structures (also known as the data schema) appropriate to the employer requirements and project team resources
• d) The process for incorporating as-constructed, testing, validation and commissioning information.

Note that once the contract is signed, for c) and d), the BIM Manager will need to complete Appendix 2 of the CIC BIM Protocol in agreement with the EIRs. This is in order to summarise the proposed Standard Method and Procedure. In particular, the summary should outline the following:

• Applicable BIM Standard
• Common Data Environment
• Spatial Co-ordination protocol
• Model approval/information exchange protocol
• Archiving procedures
• Security requirements and access rights procedures
• Resolution of conflicts
• Process for incorporating hand-over asset information, such as commissioning data.

Appendix 1 of the CIC’s BIM Protocol provides a tabular means of outlining items a) and b): For an explanation of the Level of detail/information for each project stage, please see Chapter 9.

Table 2.4 The BIM Protocol’s Model Production and Delivery Table⁸

PAS-1192 Model Federation

For BIM Level 2, each project member is responsible for organising their models and associated data in separate files that reflect the scope of their responsibilities within the overall project. At regular intervals, there is a need to coordinate these in a software environment that allows their data to be combined and used as if they were a single model. It is important to note that each discipline’s model can still function independently of others and will retain specific types of data that are not shared.

Model federation simply provides a common basis for combining, interrogating and interacting with exported models that contain information shared in accordance with agreed project collaboration requirements.

Table 2.4 reflects how model development responsibilities should be distributed among the various team members as work progresses. Further information on fig 9.1.

The extent of federation is important in relation to intellectual property. For instance, an engineer would not want to share a complex proprietary algorithm that is embedded in the structural model and that could leverage the data from any architect’s model in order to calculate the stresses, strains and bending moments. Also, consider a library of healthcare equipment that has been customised for 1:50 room layouts and room data sheets and that contains parameters capable of producing a procurement-ready Equipment Responsibility Matrix directly from the model. Clearly, in both these cases, it would make no sense to hand over data from any model that could be used by others to replicate value-adding business processes or hard-won efficiencies. Federation as described in the CIC BIM Protocol is an arrangement for sharing only as much of the model as is needed for the purposes permitted in the agreement. In the above engineering example, it means that the algorithm (and any parameters associated with it) can be stripped out of the model before issuing it to others via the project-wide data repository known as the Common Data Environment.

In the healthcare example, the architectural design model would be divided into a series of linked sub-models. While other sub-models could be shared in the format in which they were authored, the equipment sub-model might only be issued as either dumb geometry or in a format that does not facilitate the extraction of detailed product data.

In practical terms, the entire team needs to decide on how best to divide the development of BIM into several models across the project (also known as the Volume Strategy) see fig. 2.4 below and then agree on a schedule for sharing updates to each model via the Common Data Environment.

What is the Project Information Model?

In PAS-1192-2, the Project Information Model is a logically organised data structure that is defined as consisting of:

• Documentation (i.e. information preserved as records of the briefing, design, construction, operation, maintenance or decommissioning of a construction project, including but not limited to correspondence, drawings, schedules, specifications, calculations, spreadsheets)
• Graphical information (i.e. data conveyed using shapes and 3D solids)
• Non-graphical information (i.e. data conveyed using text and numbers).

Figure 2.4 Example of a major school project divided into several sub-models

It further explains that the project information model (PIM) ‘is developed firstly as a design intent model, showing the architectural and engineering intentions of the design suppliers. Then the PIM is developed into a virtual construction model containing all the objects to be manufactured, installed or constructed. It becomes the basis of the Asset Information Model once handed over.’

In practice, the virtual construction model should be developed by the construction supply chain as a full replacement of the design intent model. In response to this requirement, the task of BIM management is to outline the plan for not only organising the variety of actionable data from all project participants into a logical structure, but also for matching and linking that information to 3D elements which will increase in detail as the project progresses.

Figure 2.5 PAS-1192-2 – The whole supply chain contributes information to answer the Plain Language Questions⁴

One image taken from PAS-1192-2 indicates the potential complexity of this task:

In the highlighted area, note how the design lead and contractor lead are expected to organise their respective sub-consultants and specialists in order to provide models to a level of detail and integrated with information upon which decisions can be made at each project stage. The management of BIM must provide and implement processes for facilitating the development and integration of project data with models from all project participants, including those at lower supply-chain tiers who are not currently au fait with BIM. This is probably the most challenging part of the BIM management role, and will be explained in further detail in Chapter 8.

The Federated Model

Both PAS-1192-2 and CIC BIM Protocol refer repeatedly to the federated model, whereby each model contribution can be developed separately and then integrated by superimposing models in a 3D software environment after exporting to the agreed file format for design review (see Chapter 10).

Interoperability of Models

It is important to note that there is nothing in these documents that mandates integrating models in the application that was used to create them. For BIM level 2, each participant can create models in proprietary software. Nevertheless, it is often better to agree on a common non-proprietary file format for reviewing and querying models in conjunction with each other. One such format is the data structure known as Industry Foundation Classes, or IFC.

In order to facilitate integration, the Standard Method and Procedure should specify a common origin and orientation for all shared models.

Summary

In summary, the Pre-Contract BEP should contain:

• Roles and Responsibilities for development of the integrated model and information delivered from it throughout the project
• Summary of the proposed Common Data Environment for sharing and integrating models with associated project information
• Completed BIM, IT and resource assessment forms
• Model Production and Delivery Table
• Proposed BIM Standard and procedures for managing spatial coordination, clash resolution, model approval/information. exchange, data archival and security requirements.

Specifics to be Confirmed in Post-Contract BEP include:

• Personnel appointed to roles, responsibilities and authorities
• Agreed matrix of responsibilities across the supply chain (see table below)
• Completed forms confirming the supply chain’s capability for BIM and information Delivery.

It is worth noting that the adjective ‘native’, is often used in this table and elsewhere to describe any models that are issued in the original file format of the applications that generate them.

Common Data Environment

• Volume Strategy: How will the overall project be segmented into models representing specific disciplines, zones and phases? What is the common origin point and site orientation relative to True North for all models?
• File naming convention; Layer naming convention, where used; Information approval and PIM authorisation process
• Model Production and Delivery Table: Responsibility for element categories and their development to the required level of detail at each project stage (in line with contract and the project programme)
• IT: Agreed project-wide data repository and mechanism for file sharing and notification, process and data management systems; approved software platforms; approved information exchange formats.
• Approved drawing sheet sizes, scales and templates
• Agreed units and construction tolerances for all disciplines.

Information Management

• Required element attributes for each project stage
• Agreed project processes/schedule for collaboration and information modelling
• Information Delivery Plans (Master and Task-level). This is an extended version of the projected sheet list; beyond drawings, it names all information deliverables that are formally required of each discipline.

Survey Strategy

• The use of point clouds, light detecting and ranging (LIDAR) or global navigation satellite systems (GNSS); use of legacy data, e.g. existing CAD drawings.

Information Manager

The CIC BIM Protocol outlines the Information Management role, appointed initially by the Employer. This person is therefore a client representative.

The job involves managing the following processes and procedures for information exchange on projects:

• Initiating and implementing the Project Information Plan and Asset Information Plan, including:
  • ○ Common information structure across all project roles, e.g. non-proprietary software platforms (all levels of supply chain) appropriate to meet Employer requirements and Project Team resources
  • ○ Responsibility for provision of information at each Project Stage
  • ○ Establishing Level of information required for outputs at specific project stages by updating the Model Production and Delivery Table
  • ○ The process for incorporating ‘as constructed’, testing, validation and commissioning information.
• Agreeing formats for Project Outputs, such as data drops
• Assisting Project Team Members in assembling information for Project Outputs
• This role does not involve clash detection and model coordination, since these are BIM Coordinator activities.

BIM managers will be expected to work closely with the client’s Information Manager in order to deliver data in accordance with the agreed Employer’s Information Requirements.

Table 2.6 The Task Information Delivery Plan (TIDP) provides a schedule of delivery dates for formal file-based information exchange

Plain Language Questions – Model answers

As part of the review process conducted at the end of each work stage, the client will require information from the design and construction team that will assist in project evaluation.

For each of these reviews – known as gateways – and as a means of ensuring value for money for stakeholders, plain language questions (PLQs) are used to elicit the supplier’s response to the client’s key criteria for authorising the project to proceed to the next stage.

PAS-1192-2 describes information exchanges as the required response to these PLQs. The information exchanges (also known as ‘data drops’) supply comprehensive and consistently structured data that has been collated and exported from BIM at these key project intervals.

The table on the next page is adapted from the PLQs used by the Ministry of Justice on ‘early adopter’ BIM projects. The second column describes data drop components formulated by the design team from the federated Project Information Model.

In describing these data drop components above, you will notice that the words ‘linked’ and ‘exported’ are used repeatedly. In each case, we are seeking through BIM to ensure that the data is being re-used, rather than incurring the expense of it being re-created.

Distinctions between Roles and Official appointments

While PAS-1192 and other official documents mention a number of key BIM roles, none of these is necessarily a formal full-time appointment. The scale and complexity of the project and its information requirements will determine whether the latter is justified.

For the sake of clarity, the BIM Manager is responsible for developing appropriate firm-wide BIM standards and is also the ‘catalyst’ who ensures that they are adopted and implemented across the entire organisation. The next chapter will show how the BIM Manager’s role can be developed by encouraging and training an existing staff member to become the initial BIM champion. Nevertheless, there is the caveat that extending a role in this way indefinitely without an official appointment or adequate remuneration may be counter-productive, especially if it leads to eventual disillusionment and the BIM champion’s decision to take their acquired BIM skills elsewhere.

The role of Information Manager is project-focused and akin to that of a document controller. The distinction lies in the wide variety of data that must be vetted by the Information Manager for issue at each project milestone. This extends far beyond static hard-copy documentation to include the full range of model types that must be collected, combined and exported with other data for information, visualisation and analysis purposes.

The BIM coordinator is a project role, normally assigned to a design or construction professional on the team. This person is instrumental in reducing the likelihood of inter-disciplinary design and construction conflicts by working under the guidance of the technical coordinator in order to resolve coordination issues in the 3D model environment (as described in Chapter 5).

Table 2.7 Plain Language Questions and BIM ‘data drop’ responses⁵