Case Study

Cisco saw the potential to save $millions! by helping their workers work more productively. But was the urban legend of dual monitor use true? Did two monitors really improve productivity, or did employees just want more stuff? Cisco approached us to help them quantify performance advantages of using two monitors over one, and whether this could lead to cost savings.

We conducted two studies to investigate the dual monitor usage scenario. The first examined a cross-section of roles in common office tasks (e.g., document editing, email, and browsing). The second study examined specific roles in more intense, domain-specific activities (e.g., programming, technical writing, and project management).

Productivity benefits were generally found across conditions; however, the results and implications were far more intricate than was assumed based on previously published studies and industry articles.

First, there was an overwhelming amount of evidence that users preferred two monitors to one. Individual usability scales, questionnaire results, and the balance of comments all strongly show that users prefer two monitors.

Second, workload results showed a clear pattern of improved information processing. Using two monitors allows users to significantly increase the amount of information they can process over one monitor. Both the statistical results and user comments focused heavily on workload.

Lastly, time savings, the main hypothesis, showed that complex tasks, whether generic-office or role-specific, showed large reductions in time when using two monitors. Simpler tasks, however, did not. Most importantly to Cisco, 'core' roles like developers showed dramatic time-savings in their main tasks.

We discovered a clear advantage to using two monitors. 'Back of the napkin' calculations of savings were striking — conservative estimations of time-savings across the number of developers (approximately 10,000 at the time of the studies) and their time on certain tasks showed a possible real dollar savings of $56 million. Even for Cisco, that is a lot of savings.

Health & Ergonomics Cost Implications

Health benefits were not a direct objective of these studies, but were mentioned repeatedly in user feedback. Users reported less stress, strain, fatigue, and effort in performing tasks on dual monitors.

One user in particular thought dual monitor use was a boon for a pre-existing wrist condition, eliminating many windows management clicks and mouse movements. Other users discussed less eyestrain from a more efficient desktop layout by not having to reduce font size and/or increase resolution to see the same amount of information. Others reported less stress and fear of making mistakes from being able to quickly visually confirm actions rather than having to rely on memory or repeated back and forth window-checking.

All these benefits can potentially improve individual health and ergonomics beyond straightforward productivity and potentially reduce overall health costs, providing yet another significant financial benefit for Cisco.

Workload

We had a hunch that one of the main advantages for using dual monitors was that you could “handle more stuff”. You have two monitors, which means you can do more things, right? In scientific-speak, this is related to workload and information processing. Because the workload is less to deal with in one task, you can process more information overall. At least that was our hypothesis… We were right!

We measured this in two ways: 1) the number of windows open after each task, and 2) workload (via NASA-TLX). We also watched and listened for more insight. The results proved very interesting. In brief, users opened more windows when working with two monitors, but workload remained the same. In other words, users upped the amount of information they accessed, but kept the workload cap steady. This was pretty cool!

The figure below shows the number of open windows across task order (statistically significant). Some tasks were inherently more complex and better showed the effect. Notice also how open windows capped for 1 monitor.

Observationally we saw that some users inherently needed more "Windows Management" than others. This proved to be very interesting as those users who were more used to dual monitor use or generally more technically savvy were able to take advantage of their expertise to better optimize their working environment. Even those users without such expertise were able to quickly intuit some of the ways to take advantage of multiple monitors.

These were some of the Windows Management behavior we saw:

• Opening and closing windows frequently
• Alt-Tabbing
• Minimizing individual windows
• Minimizing all windows at once
• Resizing windows
• Repositioning windows and adjusting layout
• Scrolling within windows
• Task bar clicking or rollover
• Layering (non maximized) windows

Time and Cost Savings

Time savings was most apparent for certain tasks, most specifically tasks within certain roles. In the second study, tasks for Project Managers included working in document editors, spreadsheets, project management tools, email, flowcharts, browsers, and a calendar (the common task across all participants). Tasks for Technical Writers included working in several document editors, web publishing systems, and a calendar. Tasks for Developers included working in development environments, bug and issue tracking systems, and a calendar.

The project managers' tasks were not complex, nor did they utilize many open windows, whereas the other two roles' tasks were much more involved. The respective Windows Management information processing needs seemed to dictate which roles took greatest advantage of dual monitors.

The practical implications of time savings found from dual monitor use in Study Two by Technical Writers (16.0%) and Developers (22.7%) extrapolate to considerable cost savings across a work year. The potential annual cost savings can be calculated with the following assumptions:

• 2,000 hour work year
• 25% of time (500 hours annually) spent working on a computer doing domain-specific tasks
• $74,000 Technical Writer & $104,000 Developer salaries (respectively referenced from about.salary.com)
• 350 Cisco Technical Writers
• 10,000 Cisco Developers
• $300 average flat panel monitor cost

Technical Writer Annual Cost Savings:

• 500 hours x 16% time savings = 80 hours saved
• $74,000 salary / 2,000 work hours = $37 an hour
• $37 x 80 hours saved = $2,960 saving per Technical Writer per year
• $2,960 - $300 monitor = $2,660 cost savings per Technical Writer annually after buying monitor
• $2,660 x 350 Technical Writers =
• $931,000 saved annually

Developer Annual Cost Savings:

• 500 hours x 22.7% time savings = 113.5 hours saved
• $104,000 salary / 2,000 work hours = $52 an hour
• $52 x 113.5 hours saved = $5,902 saving per Developer per year
• $5,902 - $300 monitor = $5,602 cost savings per Developer annually after buying monitor
• $5,602 x 10,000 Developers =
• $56,602,000 saved annually

These are considerable savings, which by themselves are compelling reasons to recommend the use of dual monitors, even before considering other user types, domains, and tasks.