## 2 User Requirement Studies  
There are two types of users for our web application: substance users and their family members and friends, and treatment providers and first responders who want to find available, compatible treatment options for clients seeking substance abuse treatment. Through our needs-based study, we found the following gaps from the point of view of substance users who wish to find treatment: (1) The substance users would not know the admission policies and whether the treatment facility would accept their condition. For example, a treatment center might not admit any patients who are pregnant or patients who are on Medicaid; (2) The substance users would not know the availability or the wait time of a particular treatment or service unless and until they make a phone call to every facility that they are interested in; (3) Existing websites are often very cluttered and maybe filled with ads or other web components, which could confuse substance users and make it very difficult for them to find the right treatment facility; (4) Existing applications do not offer a way for a user to make a phone call to a treatment facility by simply clicking a link in the application. The following gaps have been experienced by treatment facilities with existing applications: (1) No dashboard or administrative panel for the treatment facilities to manage their data; (2) No option on the existing discovery platforms for the treatment facility to update their availability and waitlist for each and every drug-related treatment service; (3) No option for the treatment facilities to visualize the data entry progress for every service they register; (4) No option for the treatment facilities to add contact persons to get scheduled reminders to update the data on treatment services; (5) No option to register a treatment service with multiple time or location-based sub-services. To address the problems identified by substance users, the following features are considered to develop within the Web application as preferred solutions: (1) To show the availability and waitlists for admission dynamically; (2) To show the constraints on or restriction for admission to particular treatment or service; (3) To provide accurate information, verified and updated by treatment facilities themselves; (4) To provide quick access buttons such as call, directions, or website; (5) To provide clean web design to help those who are in need for substance-abuse treatment to get help without any confusion; (6) To provide options to filter and sort the list of treatment facilities based on various attributes including availability and waitlists; (7) To provide a flexible design that supports both traditional computers and mobile devices. To address the problems reported by treatment facilities, the following features are considered to develop within the web application as preferred solutions for treatment facilities: (1) To develop a dashboard for administrators; (2) To provide the option to register, update, and delete a service; (3) To provide the option to register multiple sub-services under a service based on location and hours of operation; (4) To provide the option to add multiple contact persons to a particular service; (5) To send email reminders to constantly update the availability and waitlists of the treatment services; (6) To show a data entry progress indicator for every service that is registered. The web application that is the closest to ours is EmeraldJennyfoundation.com [17]. It was founded in 2017 to solve the challenge of discovery of substance use treatment facility. Its search feature can filter for outpatient, residential and Medication Assisted Treatment options. However, the website lacks detailed information on the type of service offered, restrictions and requirements (e.g., insurance), and other criteria that are used to determine the eligibility. Furthermore, it does not provide up-to-date availability and waitlist information dynamically.