August 25, 2020
Until a COVID-19 vaccine is widely available, getting back to work means keeping a close watch for outbreaks and quickly containing them when they occur. While the prospects for accomplishing this within large companies seem daunting, tracking contacts between employees may be much easier than for the public at large. This blog post explains how a software application built with a new software construct called real-time digital twins makes this possible.
In an earlier blog post, we saw how real-time digital twins running in the ScaleOut Digital Twin Streaming Service™ can be used to track employees within a large company using a technique called “voluntary self-tracing.” In this post, we’ll take a closer look at its implementation in a demo application created by ScaleOut Software. We’ll also look at a companion mobile app that allows employees to log contacts with colleagues outside their immediate teams and to notify the company and their contacts if they test positive for COVID-19.
The demo application creates a memory-based real-time digital twin for each employee. Using information from the company’s organizational database, it populates each twin with the employee’s ID, team ID, department type, and location. The twin also keeps a list of the employee’s contacts within the organization (as well as community contacts, discussed below). This allows immediate colleagues and their contacts to be notified if an employee tests positive. The following diagram illustrates an employee’s real-time digital twin and the state data it holds; details about the contact tracing code are explained below:
The twin automatically populates its contact list with the other members of the employee’s team, based on the expectation that team members are in daily contact. Using the mobile app, employees can log one-time and recurring contacts with colleagues in other teams, possibly at different office locations. In addition, they can log contacts outside the company, such as taxi rides, airline flights, and meals at restaurants, so that community members can be notified if an employee was exposed to COVID-19.
An employee can use the mobile app to notify their real-time digital twin of a positive test for COVID-19. Code running in the twin then sends messages to the real-time digital twins for all contacts in the employee’s list. These twins in turn send messages to their contacts, and so on, until the twins for all contacts have been notified. (The algorithm avoids unnecessary messages to team members and circular paths among twins.) The twin then sends a push notification to each affected employee through the mobile app, alerting them to the possible exposure and the number of intermediate contacts between themselves and the infected person. Because real-time digital twins are hosted in memory, all of this happens within seconds, enabling affected employees to immediately self-quarantine and obtain COVID-19 tests.
Here’s an illustration of the chain of contacts originating with an employee who reports testing positive. (Note that the outbound notifications from the twins to the employees’ mobile devices are not shown here.)
As illustrated in the first diagram, each real-time digital twin hosts two components, state data and a message-processing method. These are defined by the contact tracing application and can be written in C#, Java, or JavaScript. (C# was used for the demo application.) The state data is unique for each employee and contains the employee’s information and contact list, along with useful statistics, such as how often the employee has been alerted about a possible exposure. The message-processing method’s code is shared by all twins. It receives messages from the mobile app or from other twins (each corresponding to a single employee) and uses application-defined code to process these messages.
Messages from the mobile app can request to add or remove a contact from the list. For new contacts, they include parameters such as the employee ID of the contact and whether the contact will be recurring. (Users also can record contacts using calendar events.) Messages from the mobile app can also request the current contact list for display, signal that the employee has tested positive or negative, and request current notifications. Messages from other real-time digital twins signal that the corresponding employees have been exposed and provide additional information, such as the number of intermediate contacts and the location of the initial employee who tested positive.
The application’s message-processing code responds to these messages and implements the spanning-tree notification algorithm that alerts other twins on the contact list. The streaming service handles the rest, namely the details of message delivery, retrieval and updating of state information, and managing the execution platform.
The following animated diagram shows how an employee can add a contact with a company colleague outside of their immediate team or with a community contact during business travel (left screenshot). If the employee tests positive, the employee can use the mobile app to report this to the company (middle screenshot). All employees are then notified using the mobile app, as shown in the right screenshot. Community contacts are reported to managers who communicate with outside points of contact, such as airlines, taxi companies, and restaurants.
The streaming service has the built-in capability to aggregate state data from all real-time digital twins. The service then displays the results in charts which are recalculated every few seconds. These charts enable managers to identify emerging issues, such as an outbreak within a specific department or site. With this information, they can take immediate steps to contain the outbreak and minimize the number of affected employees.
To illustrate the value of aggregate statistics in boosting situational awareness, consider a hypothetical company with 30,000 employees and offices in several states across the U.S. Suppose an employee at the Texas site suddenly tests positive. This could be immediately alerted to managers with the following chart generated and continuously updated by the streaming service, which shows all employees who have tested positive:
Within a few seconds, the real-time digital twins notify all points of contact. Updates to state data are immediately aggregated in another chart that shows the sites where employees have been notified of a positive contact and the number of employees affected at each site:
This chart shows that about 140 employees in three states were notified and possibly exposed directly or indirectly. All of these employees are then immediately quarantined to contain the possible spread of COVID-19. After an investigation by company managers, it is determined that the employee had business travel to Arizona and met with a team that subsequently had business travel to California. Instead of taking hours or days to uncover the scope of a COVID-19 exposure, contact tracing using real-time digital twins alerts managers within seconds.
The real-time digital twins can collect additional useful statistics for visualization by the streaming service. Another chart can show the average number of intermediate contacts for all notified employees, which is an indication of how widely employees have been interacting across teams. If this becomes an issue (as it is in the above example), managers can implement policies to further isolate teams. As shown below, a chart can also show the number of notified employees by department so that managers can determine whether certain departments, such as retail outlets, need stricter policies to limit exposure to COVID-19 from outside contacts.
This contact tracing application demonstrates the power of real-time digital twins to enable fast application development with compelling benefits. Because the amount of application code is small, real-time digital twins can be quickly written and tested. (See a recent blog post which describes how to simplify debugging and testing using a mock environment prior to deployment in the cloud.) They also can be easily modified and updated.
The ScaleOut Digital Twin Streaming Service provides the execution platform so that the application code does not have to deal with message distribution, state saving, performance scaling, and high availability. It also includes support for real-time aggregate analytics and visualization integrated with the real-time digital twin model to maximize ease of use.
Compare this approach to the complexity of building out an application server farm, database, analytics application, and visualization to accomplish the same goals at higher cost and lower performance. Cobbling together these diverse technologies would require several skill sets, lengthy development time, and higher operational costs.
This demo contact tracing application was designed to show how companies can take advantage of their organizational structures to track contacts among employees and quickly notify all affected employees when an individual tests positive for COVID-19. By responding quickly to an exposure with immediate, comprehensive information about its extent within the company (and with community contacts), managers can limit the exposure’s impact. The application also shows how the real-time digital twin model enables a quick, agile implementation which can be easily adapted to the specific needs of a wide range of companies.
Please contact us at ScaleOut Software to learn more about this demo application for limiting the impact of COVID-19 and other ways real-time digital twins can help your company monitor and respond to fast-changing events.
