E. Mitchell Swann, P.E., LEED A.P.
Anyone who has read Thomas Friedman’s “The World Is Flat” might glean an idea of where this article is going right away. If you haven’t read the book, it is a good one. About 2 years ago MDCSystems® presented at the London Construction Superconference on some of the benefits, challenges and issue associated with the use of 3D and 4D modeling technologies in the design, documentation and delivery of capital projects. Since that time, there have been even more developments – not just in the nature of the technology, but also in the level of accessibility or breadth of application. This expanded modeling regimen has come to be called Building Information Modeling or BIM.
If you are not familiar with modeling, a 3D model is just that – a model of the building in the X, Y and Z planes. However this model, unlike the balsa wood and glue model of the past is ‘constructed’ in the 3D world of computers. The basic premise is that with a 3D model one can “look at” sections or plan drawings of the building anywhere in the model in any orientation and thus allows an effectively infinite array of ‘perspectives’ from which to view a project. This pool of knowledge should head-off coordination problems during design rather than during construction. To paraphrase Confucius “A picture may be worth a thousand change orders.”
The industry has progressed the original 3D modeling concept to link real world material properties (resident in specification and equipment databases) to the model such that the model becomes more than just a ‘moveable’ computerized rendering of the building capable of showing an infinite number of drawing lines from an infinite number of drawings. Once the model is equipped with the physical properties of the objects previously represented by just “lines on the electronic page” the designer can query the model to see how those physical objects interface. The model can be used to discover potential clashes between objects, conflicts for service or access space and misalignment of the building elements (including mechanical, electrical and piping elements). With clash detection in 3D models the model can be used to find problems instead of just total dependence upon the eyes of the designer\model builder. Further evolution of modeling intelligence has allowed the designer to link even more detailed physical information as well as procurement, delivery and construction schedules. Full parametric models can even adjust design details of ‘supporting’ components when the designer modifies a core component, i.e. the surrounding framing details can change in response to a change in a type of window assembly. These elements, the framing details, the window details, the window information can be created by the design firm or by other “3rd parties” – contractors, manufacturers, subcontractors, etc.
The key to advanced modeling techniques and building information systems is the software. By developing, enhancing and expanding the collection, management, utilization and reporting capabilities of the software package(s) touching this information we can provide a truly useful, relevant and powerful model for the execution, operations and up-keep of the facility.
But the advance of the incredible value of coordinated Building Information Modeling (BIM) brings with it some significant ripples into the relationships between the team members and into the contractual arrangements that define those relationships.
If the model is developed by the designers and is used to develop the construction schedule – a task that is typically the sole province of the contractor – who “owns” the schedule? Who assesses the impact of materials delivery on the schedule? The availability of trade labour? Weather? Are these execution parameters typically an area of the design professional’s expertise? Who bears the risk in the event the project does not meet the schedule?
If a manufacturer supplies equipment or component modules for a project model, who is responsible for the accuracy of these modules? For any ‘interaction’ problems that may occur between the ‘specialty modules’ and the BIM package? Is there a difference between ‘design phase’ input and ‘construction phase’ input? Who “owns” the design?
If a change in construction sequence or installation technique is executed for expediency, cost, or as a result of field conditions, who is responsible for updating the model? For assessing the impact of that schedule change on the rest of the project? What about construction re-sequencing? Is this under the umbrella of ‘means and methods’?
Other questions regarding BIM occur at more fundamental levels. That is the question of interoperability. Which BIM platform is ‘most open’ and is the project selected platform compatible with that of all the team members? Should interoperability be a key parameter in the selection of contractors, vendors or even consultants? What about the software vendor? What obligation should there be to maintain the source code of the software?
So with all these questions and concerns, why would anyone want to use BIM?
Because at the end of the day, BIM provides for an information-rich project design, documentation, execution and operational strategy. Effective use of BIM supports faster execution with fewer change orders and more valuable information for maintenance and operation of the finished project.
You should get a better building and you should be able to run it better. This is a big plus for an owner.
So how do you deal with all of those earlier questions?
From the start of the project, the owner must decide if he or she wants BIM. To answer this question requires careful thought as the long term use and advantages and short term costs and challenges. Next, the extent to which the model is to be a “deliverable” and how the information will be used by the construction team must be defined and solidified. As a general rule, IF the model is to provide the owner 100% ‘real time’, as-built documentation of the building, the model can also be used to generate the necessary drawings used for construction. So the intended use of the model is key – is it to be a ‘tool’ of design and construction or is it to be truly reflective of the finished project and used in an on-going basis by the owner to manage the facility.
Once the decision to use BIM is made, the next item is to determine how to, or who will create, manage and maintain the model. One approach is to have the design firm create and maintain the model until the total completion of construction. This ‘single point’ approach makes managing the modeling process less complicated and gives a single point of responsibility to the model. A second approach would be to have the model developed ‘jointly’ with the design team taking the lead until completion of the design (award of construction contracts) and then the CM or GC takes the helm during the construction phase. The third and most adventurous approach would be to have a multi-party approach whereby the design and construction team enter input into the model each under their own ‘management’ and that there would be some central management ‘control’ which would govern the input ‘hierarchy’ and police the overall effort for consistency and coordination. Each of these approaches carries with it certain risks. The selection of the proper approach should consider each of the risks and the sensitivity of the project to the affected parameters. Contract language must be prepared which appropriately addresses the risks and the execution intent.
So what are some of these risk areas?
Taking a look at the “model execution” approaches above the base concerns center around managing input into the model in a coherent fashion and having enough ‘input capacity’ such that the model building process doesn’t create a bottleneck in delivering your project.
In the first model, data input into the model is typically done by the design firm. The benefits of the consistency and uniformity of a single firm handling all the input must be balanced against the potential impact on schedule from having only a single entry point and the potential for problems if the design firm tries to handle data they are unfamiliar with. Design professionals are professionals at just that – design. They are not necessarily expert at construction scheduling or sequencing or at equipment fabrication – information which will be necessary to provide a truly 100% complete model. Interfacing the model with some of the “plug-ins” that represents equipment or other construction assemblies could result in information gaps or errors which may impact the project.
In the ‘hand-off’ scenario, the biggest problem is in defining a product of ‘suitable’ completeness that the second hand on deck would feel they had received an adequate package. The meaning of ‘complete’ in the world of construction has many interpretations. The ‘hand-off’ method of execution that could create circumstances which prove ripe for misunderstandings, misinterpretation and disputes.
In the third and most adventurous approach, the model can have multiple input sources. This allows the manager of the model take precautions to insure that no one is ‘designing outside their skill set’ and it lessens the likelihood of throttling the modeling process due to a single group being overwhelmed. It does significantly increase concerns regarding coordination and quality control.
What are the results of using BIM?
From a project perspective, clearly a better coordinated, more thoroughly documented project which reflects the ‘real time’ conditions of the project is of great benefit to the owner. From a project team perspective, BIM changes the nature of relationships, it can alter the flow of the work and it requires new paradigms to deal with responsibilities, liabilities and control of the final work product. In the BIM environment each team member has far greater influence over the outcome of the project and as a result, each team member is far more dependent upon the actions of others for the successful completion of his or her portion of the work. While such interdependence within an organization (the A/E for example) is common, having those links and dependencies extend so deeply to outside firms (contractors, vendors, etc.) is a much newer scenario.
As these new relationships develop, it is important that the project’s business terms are set up to incentivize all parties to operate for the “common good” as opposed to the all too often adversarial positions that become the norm. Agreements to not sue or press claims between participants in the model development should be considered to help foster open communication between the parties. Limits of liability should be investigated to reduce the tendency to either ‘gild the lily’ or design with such timidity that no new thinking ever comes to the fore. Adequate and appropriate time should be allocated in the schedule for all team members to properly document their work not just those with the biggest financial stick. As has been described above, comparatively small items can domino into much larger problems if not addressed properly.
There is a chapter in Freidman’s book which talks about the ‘new diplomacy’ that is a result of the interrelationships of all the companies that participate in the design, manufacture and distribution of a laptop computer – and the various countries those companies are located in. As each company’s respective government comes to depend upon the tax and investment revenue created by that company’s participation in the ‘team project’ that is the laptop, each country is now incentivized to help (or at least ‘do no harm’ to) the participation capacity of another company – and its host country. To destroy a link in the chain would also destroy the loop that feeds them. This type of manufacturing has been made possible by the heavy automation and computerization of the manufacturing process and the ability to harmonize, streamline and transmit the information necessary to execute those processes. BIM is the extension of that philosophy to the old ‘hands on’ world of design and construction. It seeks to use technology to help bridge the communication and understanding gaps that are the source of so many problems in the execution of projects. The true key to communication however is a willingness to talk …and to listen. And that begins and ends with the users of the machines…the people. The machines can and will be made to talk to each other, but will we let them?