In our last HEALTHCARE DESIGN article, “Research in Practice: Lesson 2—You got a problem?” we discussed why and how to identify and prioritize the challenges facing a facility. Each problem we uncover brings opportunities for design innovations. Now that we can define the problem, it’s important to learn techniques to test these innovations.

Each day, millions of us step onto aircraft, trusting we’ll safely arrive at our destination. We put our lives in the hands of the pilots, crew, and engineers. It would be silly to think of the latest Boeing 787 being released to the public without thorough prototyping and safety checks. Likewise, countless patients fill our hospital rooms daily. They trust they’ll receive the best possible care, yet few of the environments we create are tested for their ability to facilitate care and healing processes.

As in aeronautics, there are ways to test-drive a facility or renovation. Simulations and mock-ups allow for testing of design and operational concepts. Test-drives provide the opportunity to take a project to a new destination and inspire design innovation. They can validate design decisions without the risk of full implementation in a building project.

In this article, we demystify simulations and provide practical advice on maximizing the benefits of test-driving your planned facility.

Whether it’s an aircraft or hospital, each simulation is based on an underlying model. For aircraft testing, we might think of a small model of a plane, tested in a wind tunnel that simulates real-world scenarios. This model is an abstraction of a real-world system (i.e., the built plane), with underlying assumptions (i.e., plane shape, material) that represent how the system behaves. In this case, the simulation is the act of repeatedly testing the plane in the wind tunnel. We can use the results of these tests to draw conclusions about how the plane will act in the real world.

Models are not just physical: They can also be virtual, computational, or numeric. In our 2012 article, published in the Health Environments Research and Design (HERD) Journal, we identified four primary types of simulations and mock-ups used in design: (1) physical mock-ups; (2) virtual mock-ups; (3) dynamic simulation models; and (4) static simulation models.


From the pilot’s seat: Mock-ups
Mock-ups are a type of experience-based model, focusing on the sensory experience of the space. In a plane, this would be the pilot’s distance from control panels, ease of changing altitude, and the readability of the dashboard. Mock-ups transform line drawings into a three-dimensional understanding of space and use. Here, teams can discuss implications of design decisions, manipulate the environment, and test possible design changes.

There are two types of mock-ups: physical and virtual. Physical mock-ups are built in full scale and can be directly experienced by all the senses. These mock-ups can fall into three stages or categories based on their use and level of sophistication: simple, detailed, and live. A simple mock-up is typically constructed of foam core, cardboard, simple props, and print outs, including tape on the floor and walls. These models are inexpensive and easy to manipulate and as such can be empowering to the design group, who can adjust the mock-ups in real time.

Detailed mock-ups are the second level of sophistication and provide a realistic representation of the final design. These mock-ups help the team consider the materiality of the space and choose color palettes, finishes, and equipment placement. They provide an excellent platform for running care simulation scenarios and allow the team to verify that design decisions made in the simple mock-up still hold once the details are added.

The final step in the mock-up process can be a live mock-up. This is created when a detailed mock-up is activated into a fully functioning room with patients (e.g., fully functioning plumbing, gasses, and equipment). A live mock-up works best within a replacement or renovation facility, where the mock-up takes the place of an existing room. This allows a comparison between the newly designed and the existing spaces. Recording outcome metrics from each room allows us to understand the new design’s impact.

For the creation of University Medical Center of Princeton at Plainsboro in New Jersey, HOK proposed a full spectrum of physical mock-ups, bringing to life the initial planning and architectural drawings in a series of physical mock-ups.

Phase 1 of the mock-ups consisted of a two-stage process to evaluate a simple mock-up. Stage 1 included individual staff walk-throughs and questionnaire responses. Here, participants explored the environment and responded independently without consulting other participants. Stage 2 entailed group discussion and manipulation of the mock-up environment. Participants explored possible design alternatives and discussed varying perspectives.

Findings from the Phase 1 investigations had implications for design decisions in the final room design and revealed opportunities for innovative design to respond to specific challenges raised by participants, such as bedside charting. Other design choices included: (1) use of a balanced headwall design, with similar gasses and outlets that are mirrored on both sides of the bed, with oxygen closest to the bed; (2) reconfiguration of the bathroom for easier access and assistance of patients; and (3) provision of a hand rail for patient transfer from bed to bathroom to reduce slips and falls. Each phase of the mock-up allowed the design team to improve upon the initial mock-up and validate design decisions that benefited the final design.

Virtual mock-ups, often referred to as virtual prototypes (VPs), are typically set up in an existing space (such as an empty office or conference space) and allow the user to interface virtually with the designed environment. They require little to no physical construction, and can interface with an existing BIM or other 3-D model. For this reason, VPs may offer a quicker, more cost-effective alternative to the traditional physical mock-up.

Additionally, they can be quite easy to manipulate, and allow the user to test different color and interior schemes that would take a longer time to test in a physical model.

The challenge with these models is to have them be as immersive and detailed as a physical mock-up can be so users’ reactions are valid. Case in point, the use of technologies such as avatars, 3-D goggles, and Cave Automatic Virtual Environments (CAVEs) are increasingly being used to create a more realistic experience.

One example of using VPs in practice occurred when HOK designed the new Walter Reed National Military Medical Center in Bethesda, Maryland. In a study published in 2011 in the HERD Journal, HOK collaborated with Maquet and Naval Facilities Engineering Command, using a virtual mock-up as part of the operating room (OR) design research and validation.

In this study, Nicholas Watkins, PhD, and colleagues used structured focus groups to gather input from surgical staff on the proposed design, and integrated their feedback into the final design iteration. One change the research identified was the benefit of moving the OR control desk to the foot of the operating table so the nurse could have a clear view of the patient.


Taking flight: Computer-based simulations
Computer-based simulations (CBSs) are made up of numeric data, which are input into a spreadsheet or sof
tware and displayed numerically and diagrammatically. While experiential mock-ups address a person’s firsthand experience of a proposed space, CBSs offer a bridge to better understand the role of the operational systems within that environment. Although both VPs and CBSs utilize a virtual environment, they differ in that CBSs are concerned with the operational system within that environment, whereas VPs address the personal experience of the space.

The value of a CBS relies on the accuracy of the model it is based upon. This requires that the model include accurate assumptions related to actual patient volumes, procedure times, clinician schedules, travel distances, etc., at the participating facility. Consequently, an effective CBS requires an initial investment of time for data collection, including time-motion behavior observations, process mapping, and interviews with staff.

A built environment and the activity that occurs within it are closely linked. These simulations facilitate the creation of an operational model that reflects the facility’s needs and provides an understanding of the environment’s impact on operations.

Computer-based simulation models used in the design process may be either dynamic or static. In a dynamic simulation model, the progression of a process over time is revealed. These models incorporate natural variability in processes and are often animated. Static simulation models represent a system at a particular point in time, and often do not factor in natural variation and randomness. These models take significantly less time to create and allow the user to create a base that can be used for forecasting and programming.

In the design of Kaiserslautern Military Community Medical Center (KMCMC) in Kaiserslautern, Germany, the team was interested in exploring the impact of design and operational innovations on care delivery. For this reason, dynamic simulations were used to examine process improvement, resource use, and patient experience.

We started by identifying key patient pathways to represent the overall patient population and then created process flow diagrams for those pathways. Operational and procedure times, patient volumes, and the clinical schedule are integral in creating a reliable simulation. These simulations were used as base cases to start examining the impacts of design. It will be important in the future to further engage clinical management to ensure understanding of existing processes, develop further detailed patient pathways, and test operational models.


Choosing your flight path: Which route is best for you? 
Each type of simulation model offers benefits and challenges and can be leveraged for different projects depending on project goals, schedule, and budget. The table on the previous page shows a comparison of some of the basic benefits and challenges.

Simulations and mock-ups are an increasingly common tool in the design of healthcare facilities. It’s important to provide participants with a structured, objective, and interactive format for responding to these models. This format creates valid and reliable results that serve as a foundation for future innovations.

Achieving the benefits of simulations and mock-ups requires an initial investment of time and financial resources. It’s important to have a strong framework that integrates these tools into the overall project schedule, utilizing just-in-time findings from the research to cycle into the design process. Project manager engagement is essential for successfully integrating design research and simulation modeling into the larger project scope.

Having early and ongoing discussions with client representatives about simulations and mock-ups is an important part of educating the team and ensuring timely project delivery that meets both budget and expectations.

It’s essential to validate the results derived from simulations and to follow up to determine whether the predicted benefit was achieved. Our next “Research in Practice” article will focus on post-occupancy evaluations, which begin to compare expected outcomes with results from the real world.

Erin Peavey, Associate AIA, LEED AP BD+C, is a researcher and medical planner at HOK in New York. Nicholas Watkins, PhD, is senior associate, director of research, and firm-wide knowledge specialist, at HOK in New York. The authors would like to thank contributing team members and colleagues including Chris Korsh, Richard Saravay, Stephen Thomas, Derrek Clarke, and Chuck Siconolfi. Erin Peavey can be reached by phone at 212.981.7303 or by email at For more detailed methods on carrying out mock-ups and simulations, please visit