yellow caution tape on elevator reminding to keep your distance during COVID-19

The Elevator Constraint: social distancing in office elevators

By Dale Lawrence

Ready for a busy day? Your first day back to the office. Got your Americano? Check. Look at your phone and see that you still have 15 minutes before your meeting. Just enough time to catch the elevator to the twelfth-floor office, check email and then review some documents for your client meeting. However, as you approach the lobby, you see a line of people. Upon inspection, they are queuing with socially distanced spacing for the elevators. This is not good! Looking at the time again, you know the ability to get ready for the meeting is doomed. Due to the limited number of passengers allowed on each elevator, you know you will not make the call and likely will be here for 30 minutes or more.

Sound familiar? During the rush to bring business back in the time of COVID-19, this will become an inconvenience to millions of office workers and a major burden on productivity. It will occur four times a day EVERY workday.

The Social Distance Challenge

Most people don’t think of how elevators work. Pulleys, counterweights, resistors, motors, computer board, safety systems. You just push a button and the familiar sound notifies you that your elevator is about to arrive. The doors open and your trip starts. Depending on other passenger needs, your trip may be direct or have a number of stops. We take this for granted.

However, during this pandemic, the issue isn’t how many people ride with you. It is how few. As most elevators don’t have the space required for a six-foot distance for passengers to be safe, the only way to avoid risk is allowing very few passengers at a time and ensure cleaning of contact surfaces often. While some businesses are placing social distancing markings on the elevator floor, does that provide the necessary space?

Elevators were not designed for social distancing.

The Introduction to Flow Constraint

The impacts from COVID-19 are many and the return-to-work will just introduce more challenges to business. The elevator seems like an innocuous part of office life, but in reality, it is a serious constraint to the basic flow of people. Normally efficient but think of the rare days when one of the elevators is closed for maintenance. That adds extra delays but is usually manageable. Now think of almost all elevators closed for maintenance; the bottleneck would be significant.

Like all systems, any constraint to flow has an impact. From a high-level system view, the objective of the elevator is to safely and efficiently move people from point A to point B. Think of the objective as ‘100% safe delivery of people to their desired destination as-quick-as-possible’. In a production or manufacturing facility, any reduction of the efficient flow is called a constraint and the by-product creates inventory. This inventory typically gets stuck prior to the constraint, increases and costs the operation money in lost sales, productivity and efficiency. Now shift back to thinking of the movement of people instead of producing a product. The disruption to moving people on the elevator creates a backlog of passengers. This backlog creates an inventory of people waiting for the elevator. This inventory will cost you money in lost productivity. Unlike inventory, the people involved also feel frustration.

Elevators are becoming the bottleneck in the office.

The Impact to Productivity

The typical elevator office passenger takes four trips per day, 250 days per year. This represents a transportation delay for your workers to arrive at their desk or workstation on time. In fact, a study conducted by IBM in the early 2000s with almost 6500 office workers in 16 US-based cities found the accumulated time spent waiting for elevators during workdays was significant. In New York City alone, they found the accumulated time for the city’s office workforce waiting for elevators exceeded 16 years annually in lost productivity. While elevator manufacturers have made significant improvements in the last few decades, COVID-19 will cause a major disruption to an already complex daily routine.

An Illustration

Imagine a 40+ story office tower with 2000 workers who normally arrive daily. Back to my earlier analogy, the system requires a movement of 2000 people, four times a day for an expected 8000 trips. Pre-COVID, increasing the number of riders per trip reduces the number of elevator trips. As an example, an average of 7 passengers per trip across 4 elevators would result in 285 trips per day, per elevator.

Now think of the current COVID situation. An effective social distancing approach would now significantly increase the number of trips per day. Depending on how few passengers are determined can safety travel at one time will determine how many additional trips are required (the question also comes to who decided the new capacity – based on health expertise or building management decision?). A CDC study found that the virus can travel up to 13 feet as an aerosol and while they didn’t look at elevators, distance should be maximized. This creates a big challenge to normal elevator capacity.

The problem is compounded as elevator trips are not all created equal. There is an added level of complexity since the vast majority of trips are likely between three periods of time:

  • 7:30am-9am
  • 11:30am-1:00pm (likely two trips per person as most businesses have closed the office floor kitchen area)
  • 4:00pm-5:30pm

These rush periods likely mean the number of passengers greatly increase over the average (likely doubling the average number of passengers) while most of the 2000 workers utilize the elevators during each window of time. When modelling social distancing and factoring peak times, the impact could be an increase of 100% the average trips per day but 300-500% the number of trips during daily peak times. This would cause the backlog to be beyond the elevator’s ability. Imagine waiting 45 minutes for an elevator, four times a day?


  • Minimum: Building maintenance provides constant cleaning throughout the day and supplies hand sanitizer inside every elevator car (studies have shown the virus lasts longest on stainless steel and plastic). While this increases cleanliness, it doesn’t reduce the passenger constraint and won’t decrease risk from aerosol spread. 
  • Minimum: Mark standing areas and provide clear guidelines for conduct such as requiring all passengers wear a mask and avoid talking. Note: some building management are even asking passengers to face the elevator walls.
  • Possible but challenging: Provide elevator passes to even out the flow. This will drastically increase complexity but can provide some options for reducing peak time challenges. This does add a great amount of daily administration effort (especially for multiple tenants) and has many challenges regarding workload modelling, compliance & enforcement.
  • Best option: Decrease the number of all onsite workers more than 60%:
    • Administration (finance, human resources, clerical etc.) can mostly work remotes and often have standard shifts.
    • Management can work remotely at least half of the week.
    • Sales and call center workers can become partially or fully remote workers.
    • Assess suitability for ‘resident’ (always onsite), ‘partial remote’ and ‘fully remote’ profiles for all workers. Ensure processes and the worker and leadership habits adapt to this new normal.
    • When properly implemented, this will save the company money and improve the productivity and culture.
    • Don’t only look at this as ‘remote work’ but ‘Flex Work’. This isn’t only about the physical aspect of work but has the potential of revolutionizing how work is done in your business.

At Propulo Consulting, we partner with you to improve the world of work. Our team has the expertise to help your business plan and implement a sensible Flex Work strategy without pain. We work with you to ensure your company culture and processes develop accordingly during or after a Flex Work transition so you can continue to deliver results for your organization and customers.


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