Best Practices: Progressive Design-Build in the Transit Industry

Progressive Design-Build (PDB) is increasingly gaining popularity as an alternative delivery method within the transit industry. Although it’s becoming more common, its execution has not been standardized. This paper aims to speak to the unique attributes of PDB, along with best practices, in an effort to help the entire industry as we continue to create a more connected country. 

 Similar to Design-Build, in a PDB the designer is part of a design-build team contracted directly with the client. However, unlike most design-build projects, selection of the PDB team is not based on a lump sum price. Instead, it draws on the collaborative attributes within the Construction Manager / General Contractor (CM/GC) model to select the most qualified team to evaluate project risks and scope, leading to  a guaranteed maximum price (GMP) after the project risks and scope are well understood.   

 Setting up a PDB Project for Success  

  The common thread throughout every phase of a PDB project is collaboration. While vital to the success of any project, it’s more critical than ever in PDB. Thus, it’s up to everybody involved to maintain a vested interest — problems can’t simply be pointed out, they need to be solved before they have a chance to occur.   

  Trust is paramount, and has to be earned, which means transparency and alignment must be maintained throughout the duration of the project. A lack of transparency can lead to conflict or the loss of trust, so creating clear scopes and maintaining shared assumptions is crucial.  This starts at the top - with total buy in from project leaders from the PDB team, client, client's consultants, and key project stakeholders who are committed to leading by example and nurturing trusting relationships. 

  To that end, leaders within Stacy Witbeck have identified nine key best practices to adhere to based on their experiences navigating successful PDB projects:  

Maximize the Value of the Validation Phase 

 As PDB is still a fairly new delivery method in the transit industry, focusing on the above best practices allows organizations to replicate successful results on projects. Alongside them, however, come some unique challenges that are important to keep in mind. 

 Determining what is in-scope versus out-of-scope within the design can be a challenge. As the value engineering effort takes place, it’s crucial to have a strictly defined and finite start and finish period within a PDB project. This helps prevent unnecessarily dragging out pre-construction and introducing scope creep within it. The value engineering phase should end within one to two months of the Notice to Proceed (NTP). 

 Managing pricing on open and undecided items, such as design, can be a significant obstacle. 

The entire team needs to work tightly together to mitigate large unforeseen costs that could negatively impact the project. Because of this, the team must treat estimating as a consistent, full-time activity rather than a deliverable-based job with a set number of hours allocated for each estimate, as is commonly found within other alternative delivery methods.  

 Keeping estimating engaged allows estimates to constantly update as more information is learned, keeping them accurate at all times and helping offset the challenge of open items. This elevated level of collaboration allows the entire team to further foster trust between one another, and within the overall estimate. To help grow this trust, it’s important to always provide a clear and transparent backup alongside the estimate. 

 Similarly, developing and documenting a shared list of assumptions and clarifications can help ensure the entire team is using the same playbook. To reiterate what was previously stated, trust is paramount for a successful project. The best way to earn that trust is for all members of the Progressive Design-Build team to show their work each step of the way, ensuring all are working off the same set of assumptions. 

 While these items are specifically related to the validation phase in pre-construction, the practices learned within them should carry throughout the life of the project. Continuing the spirit of collaboration through constant communication helps avoid preventable issues. Once construction begins, it’s helpful to create a simplified construction schedule with meaningful milestones.  

 There’s no way around it – designing and constructing large infrastructure is complex. It may be due to that reason that the results are some of the most rewarding and iconic landmarks in the country, connecting individuals in a myriad of manners. Progressive Design-Build isn’t the end all be all solution to helping these projects achieve their goals, but it does provide another way to accomplish them. Allowing collaborative, and equitable, projects to shine in the manner they deserve.