Leaning into IPD: A primer for engineers
- Learn the definitions of design-assist, design-bid-build (D-B-B), design-build, integrated project delivery (IPD), IPD light, and value.
- Understand the workflow differences between D-B-B and IPD.
- Review lessons learned from a recent health care project.
Rather than detail what the workflow for a traditional design-bid-build (D-B-B) delivery method looks like and then detail out what an integrated project delivery (IPD) method looks like, we’ll dive directly into how IPD is different.
First, there’s the team that will include the owner, architect, engineer, and contractors. The formation of the team by the owner is critical, especially if most of the team members haven’t worked on a project together before. In fact, the formation of the team becomes especially critical if most of the team members haven’t worked on a project that’s used an IPD method.
Respect among all the team members is paramount to build trust so that the intense communication required can happen as naturally and as easily as possible. The team needs to very quickly get to a point where proactive integration replaces reactive coordination. These principles will apply not only to all the folks on each team who are typically involved at the beginning of a project, but also to the other team members that will participate throughout the project including specialists, designers, and field staff.
Any team members who have had experience with adversarial relationships on previous D-B-B projects will need to work hard to shed any preconceptions they might have about how this alternative delivery method will work in order to contribute to a successful IPD project. An IPD coach can help a lot with this critical foundational principle.
Keep in mind that engineers tend to think iteratively, especially when working on design/construction projects, and contractors tend to think linearly as they build things (Figure 5). In an IPD scenario, the engineers and contractors will need to approach their roles with both types of thinking. This will be a challenge for each of them, so they’ll need to be made aware of this phenomenon and discuss it thoroughly to work together most effectively.
How to sell IPD
One way to sell IPD to engineers is to stress that they’ll become more cost-conscious and practical problem-solvers as a result of working closely with the contractors. They’ll become more aware of constructability issues, in general, and more aware of site-specific issues, in particular-especially if the contractors on the team happen to be the “incumbent” contractors at the facility.
To sell IPD to contractors, stress that they’ll learn more about system design; in fact, they should be invited into early phase meetings with the “end users” of the project, which should deepen their understanding of the design intent of the project.
This extra insight available to both the engineers and the contractors will benefit the owner because the owners’ level of uncertainty related to what they’ll eventually end up with should be minimized.
Another important factor to consider that will have an impact on the engineer/contractor teams’ ability to succeed is early involvement by the owners’ facility manager including their lead engineers/mechanics and incumbent building automation system vendor, commissioning agent, gas/vacuum verifier, compliance-testing agency, etc. Not only will these specialists have crucial information and experiences to share with the wider team, but they’ll need to be included in critical system design decisions to more fully guarantee that the end users get what they’re expecting.
Also, there’s the contract. Finalize this as soon as possible, preferably before any of the planning, design, or construction is started. Having a contract drafted early on in the project allows a fully developed BIM implementation plan to be integrated into, and referenced by, the integrated form of agreement (IFOA).
This step will help flesh out who does what. Will the contractors be responsible for documenting existing conditions? Will they be responsible for testing the performance of existing fan systems? Who designs and documents what parts of each mechanical and electrical system? Who does the quality analysis? Who stamps and seals the basis of design/calculations, plans, and specifications? Will submittals be required for materials and equipment or just the equipment? Will submittals be required for all layouts or just congested areas? Can the IFOA accommodate a value-added change to the project during the design phase that increases the first cost but reduces the lifecycle cost?
Another consideration involves the tools and the process. High-performance tools and a high-performance process puts engineers in the position of being able to deliver high-performance solutions when the opportunities present themselves. The tools and process also are critical to the execution of a project using an IPD method because the design process in an IPD project occurs much earlier in the schedule (Figure 6). Experience suggests that the owner’s decision-making and the authority having jurisdiction’s (AHJ) review/comment become the critical path tasks in an IPD project. These efforts require intense communication at the outset of the project, with commitments made and kept by all interested parties.
Start with a traditional work plan that defines tasks in a chronological order, with start/end dates and personnel assignments supplemented by “pull planning.” Task-by-task planning helps everyone on the team understand how their specific tasks impact all their teammates. Because pull planning leads to building and executing a faster schedule, not only can time be saved, but the risk of the most costly type of litigation-the dreaded “claim for delay”-can be avoided.
Engineers tend to be process-oriented, so IPD will require that engineers stretch outside their comfort zone to embrace a different sort of process. Some steps will remain the same and be executed in a traditional manner. One example of this is the development of an owner’s project requirement (OPR), which defines the end users’ needs, wants, criteria, etc. Another example of this is the basis of design (BOD), which defines design criteria and systems descriptions that need to respond to not only the OPR, but also to the applicable laws/codes/standards, climate, utility rates, etc.
The development of the BOD needs to occur with the contractors’ help instead of simply having them review it when the engineers are done with it. The contractors can make the engineers aware of various operations and maintenance (O&M) issues that they know should be considered as part of the design of new systems. In addition, the contractors can help with the development of the BOD by pretesting any existing systems that are to reused.
Additionally, calculations will be needed to supplement the BOD. The calculations typically are prepared by the engineers. But in IPD, even the calculations should be done collaboratively. For example, while the engineers are estimating airflow demands and static-pressure requirements for a toilet exhaust system, the contractors can simultaneously work on toilet exhaust duct-distribution layouts and estimate allowable leakage per HYPERLINK “https://www.smacna.org/” Sheet Metal and Air Conditioning Contractors National Association (SMACNA) so that the engineer can more quickly make appropriate fan selections. This type of workflow adjustment/sharing is exactly what needs to be defined at the outset of the project.
In keeping with moving the bulk of the design forward in the schedule to maximize the opportunity to impact first cost and minimize the cost of design changes, the prepurchase of major mechanical and electrical equipment, such as boilers, chillers, cooling towers, generators, etc., can be instrumental in achieving a successful outcome. Prepurchasing major equipment has several benefits including using bid information to select equipment with the lowest lifecycle cost, buying high-cost items early so that adherence to the budget can be assessed earlier in the schedule, and being able to design the distribution portions of systems due to knowing all the engineering parameters of the major equipment that form the heart of the systems.
Another strategy is to design and document certain critical/repetitive portions of the work in great detail (i.e., toilet rooms, offices, classrooms, medical-surgical patient rooms, operating rooms, etc.) to allow the team to analyze and optimize those segments of the work. Some of these spaces/systems can then become candidates for prefabrication.
Yet another strategy to move design along, leaving as much of the documentation for later in the design phases (preferably to be done by the contractors), is to really scrub through the engineering standard details early so that they can be enhanced to carry more info, thereby allowing the level of documentation to be minimized. This leaves more time for both the engineers and the contractors to focus more on space use and new technology.
Finally, another strategy is to ensure that energy modeling and the beginning of commissioning activities are planned for the early design phases.
Other best practices include:
- Continuously cost estimating in lieu of at end of discrete design phases. The goal is to have no surprises at the construction document phase.
- Collaboration between all team members, giving the team a much better chance to anticipate changes that could occur during the later design phases, construction, and O&M.
- Establishing co-location (don’t just “phone-in” conversations). Commit to some sort of practical, effective arrangement. There are too many “in the moment” discussions that occur that can’t be scheduled; sometimes a problem or a solution just pops into your head that is best sorted when it happens.
- Emphasizing quality assurance with a more ad hoc teaming sort of arrangement; brainstorming, quality control, and lessons learned are important sets of tasks that need to be carefully planned out.
- Taking a very proactive and iterative approach; architects waiting for the owners’ work to settle down or the engineers waiting for the architecture to settle down won’t work too well.