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Use-Case Model
The use-case model used in this document to describe (mail)n^ is accomplished using the ‘fully dressed’ format. Given the nature of the system, it is empirical to enumerate as many details as possible about the system for completeness. Before presenting the use-case scenarios, we must illustrate the relations between actors and their goals. Namely: Actors Goals Web-server Inter-median between the database and the mail server and the user. It also provides an interface for the user. Mail-server This is where the emails are stored at first. They are held there until they are read and processed into the DB Database Stores mail messages, contact information, and task information. Also returns information when queried. User Must be able to send, receive, read, and store emails. Must also be able to manage contact groups and tasks. Administrator To create, or delete an account within the system. Having identified the set of ‘actors’, and their respective goals, we continue to map out the first use case scenario, in which the primary actor is a user. Use Case UC1: Processing Messages Primary Actor: User Stakeholders and Interests:
- User: Wants to navigate through the email system easily and be able to send, receive and store emails. In addition, the user also wants the ability to manage contact groups, and edit tasks.
- Administrator: Wants to be able to create, modify or delete accounts.
- Company: (given that (mail) n is used within a corporation, although it could be used by anyone.) Wants to ensure that all of the employees using the system can easily do so without the need of someone to assist the employees. Also, the system has to be virus resistant, because employees will rely on having the ability to store information. The information must be guarded for safe retrieval. Preconditions: User is connected online, and is using a modern web browser. Success Guarantee (Post conditions): Emails are sent, received and stored. Tasks are correctly managed, and contact information is correctly updated. Administrators have full control over the user accounts.
Main Success Scenario (or Basic Flow):
- User connects to the Internet.
- User goes to the (mail)n^ web site.
- User enters his/her user name and password.
- The system verifies that both user name and password match with the contents in the database.
- The user is now logged into the system.
- The first screen that the user sees is the ‘inbox’ screen.
- From that point, the user may click on a particular unread message to view its content, or choose to perform any other available option.
- Assuming that the user reads an unread message, and wishes to reply, either to the sender, or to the sender and the CC’s, the user clicks on the “Reply” button.
- A new screen appears in which the user may enter the recipient information, a subject line, and the body of the email.
- After writing the email, and filling out the “To:” field, the message is ready to be sent.
- The user clicks on the “Send” button.
- The user is then presented with a “Message successfully sent” message upon completion of the sent action.
- The user is redirected to the inbox screen, where he/she may continue to browse emails.
- The user chooses to terminate his/her session.
- The user successfully logs out. Extensions (or Alternative Flows): At any time, System fails: To support recovery and correct storing of emails, ensure that all messages are stored into the database once the messages are read by the user. Emails will not be lost due to a local machine failure.
- User restarts machine, connects to the internet, logs in, and emails are still present.
- System keeps messages in external machines, not available to the user, so the messages are kept safe.
- Invalid identifier:
- System does not match the string of username, and/or password with existing usernames and/or passwords in the database.
- System rejects entry, and redirects user to the initial screen where the user may attempt to log in once again.
- Internet connection is lost:
- When reconnected, the user must enter his/her username and password again.
- Loosing Internet connection is the equivalent to logging out.
- System detects failure to connect to mail server:
- An error message will display, stating that the mail server is temporarily out of service. 6a. The user does not fill out required fields of a message:
- At least one valid recipient’s address must be provided to send a message.
Vision
Revision History Version Date Description Author(s) Inception draft October 27, 2004 First draft. Will be refined during the elaboration phase. Joseph Aulisi Elias Rosero Jwalant Dholakia
Introduction
Our team sees (mail)n^ as an email program designed to house all the email received by an organization and its users in a form that is easily searchable, expansive, and permanent.
Positioning
Business Opportunity Organizations today have a wide variety of email systems from which to choose, though none of them guarantee against data loss, and many are prohibitively expensive to employ and maintain. Although many systems offer users the ability to view their email via a client program installed on the user’s machine, or via a web-based client, email itself is stored in proprietary data files, or plain text files, which can grow quite large, thus becoming unwieldy, and can have an adverse effect on the speed at which mail is retrieved and read. Problem Statement Email systems today are not secure and can potentially lose the data they were designed to store. Many systems that store email messages in a proprietary format keep mail in a single file, which, over time, is at a high risk of corruption. When this corruption occurs, users can expect to lose all of their messages. Some systems, due to their omnipresence, are often exploited by malicious virus attacks, which can compromise a client machine and propagate around the world in a matter of minutes, leaving a path of infected computers with no chance of recovering data. Product Position Statement (mail)n^ is designed for use by small to mid-sized organizations that are looking for an email system that provides its users with the ability to view their email securely from any web browser. Each user’s email is stored in a database, which offers a virtually unlimited mailbox size for each user, and offers the ability to quickly locate past emails. Apart from being a rock-solid email program, (mail)n^ offers a convenient contact management tool, and a task database, which allows corporate users the ability to schedule inter-office meetings. Alternatives and Competition Currently, there are many alternatives to (mail)n, including Microsoft Exchange, Lotus Notes, and even outsourced email services. One of the problems with outsourcing email
is the mailbox size limit that vendors place on services. (mail)n^ offers an unlimited mailbox size for all users on the system. Microsoft Exchange and Lotus Notes are pricey alternatives, requiring the purchase of hardware and software, but also the presence of someone with the skills to administer these services.
Stakeholder Descriptions
Stakeholder (Non-User) Summary Major stakeholders will be business owners in a position to decide the best, most efficient and cost-effective way to manage mail. Those who decide on which mail system to roll out are the ones who stand to lose the most, should the system fail. (mail)n^ offers a worry- free solution. User Summary Two types of users, administrators and employees, will be using (mail)n. Employees are standard users with no administrative privileges. Administrators, on the other hand, have more privileges, and are responsible for adding employees to the system, among other tasks. Key High-Level Goals and Problems of the Stakeholders High-Level Goal Priority Problems and Concerns Current Solution World-wide accessibility High Will the system be available when users travel? Most solutions offer a web access to email. Unlimited storage High^ Will the system grow with the company? Online services offer a service with a hard limit on disk quota. Security High Will the system be resistant to viruses, worms, and prying eyes? Bugs in current systems can allow for such attacks. Ease of use High^ Will there be a need for training? Most email systems are easy to use, but can become bloated with too many features. User-Level Goals –Employee: send, receive, and save emails, store contact information, set up tasks. –Administrator: backup mail system, set up users easily. User Environment Employees and administrators will be able to access (mail)n^ with any modern web browser, from any computer connected to the environment.
Product Overview
Product Perspective (mail)n^ will reside on a robust computer system housed within the walls of company, or within a co-location service. It will provide services to all the users of an organization,
Supplementary Specification
Revision History
Version Date Description Author(s) Inception draft October 27, 2004 First draft. Will be refined during the elaboration phase. Joseph Aulisi Elias Rosero Jwalant Dholakia
Introduction
This section documents various (mail)n^ requirements and specifics not captured in the use cases.
Functionality
Logging and Error Handling Make a log of all identified errors for future review. Pluggable Business Rules Depending upon the requirement of client Company some minor modifications in the look and feel of the system (like changing menu system, color, adding company logo etc) can be added. Security (mail)n^ is a web-based e-mail system. So, in order to ensure that only company employees who have the right to use the system are using it, and no one else, user authentication is of prime importance.
Usability
Human Factors
- (mail)n^ is going to be used in an office environment by employees and company administrators. The employees might end up spending a good deal of time using (mail)n^ in any given day. So, it is extremely important that (mail)n^ is user friendly.
- The text size should be large enough so that it does not get difficult and cumbersome to read messages after an entire day in front of the computer screen.
- The employee should be given an audible signal when a new mail arrives because he might not be constantly monitoring the (mail)n^ browser to check for new mails (Proposed).
- It is also important that the new incoming messages do not take too much time to open up as this might increase the frustration and stress on part of the employees using (mail)n.
Reliability
Recoverability If the server or internet connection is down, an employee might not be able to access his mails on (mail)n. This might be a bottleneck for the system but it does not seem to be a critical issue. No further decisions are made about it as of now. However, if the system goes down because of some internal error (like database server crash, invalid query etc) the system should be set up in such a way that it recovers as much unsaved data as possible and restarts itself.
Performance
A consistent and efficient performance of (mail)n^ is important. But after all, (mail)n^ is a web-based application involving a Wide Area Network. And sometimes this network might go down and bring the application to a halt. Factors like these create a bottleneck on the performance of (mail)n. Further performance issues will be identified once the system is up and running and in production use.
Supportability
Adaptability (mail)n^ can be set up to be used by an administrator or an employee. Depending upon the user type certain privileges (like adding new users, deleting users etc) are allowed. Configurability (mail)n^ has the functionality to classify incoming messages into various sub-folders depending upon desire of the system user. (mail)n^ is definitely configurable in making e- mails organized and systematically classified.
Implementation Constraints
(mail)n^ is developed using Java, and PostgreSQL as well as other components. The main reason for this was ease of use and ability to modify code efficiently in the future if needed.
Purchased Components
We were able to set up the server on a test basis using existing hardware. No purchased components are identified as of now.
Network and (mail)n^ server are up and running. In this case, the company might be willing to invest in a stand-alone computer that is directly connected to an outside network to access important messages.
Glossary
Revision History Version Date Description Author(s) Inception draft October 27, 2004 First draft. Will be refined during the elaboration phase. Joseph Aulisi Elias Rosero Jwalant Dholakia Term Definition and Information Aliases (mail)n^ Email system where all message information is saved to an object relational database, allowing unlimited mailbox size, and a secure, easy to use interface Message An individual email sent or received by a user of the system Mail, email Inbox A virtual repository of new, unsorted messages Sent folder A virtual repository recording messages that have already been emailed from the user’s account Deleted folder A virtual repository of messages a user has removed from the inbox, but is not ready to permanently remove from the system Folder A user-defined repository of filed messages Log in The action of supplying a id and password in order to gain access to (mail) n Log out The action of leaving (mail)n^ securely. Session The time starting when the user logs in until the user logs out Module A distinct feature of (mail)n, including the mail module, the contacts module, and the tasks module Contact Any entry into the contacts database that includes information about a person, such as name, street address, business, email address, and telephone number Task Any entry into the tasks database that describes an event, or appointment with the attributes of date and time Event, appointment, meeting Search An action of iterating through the database to find a particular piece of information Username A unique identifier for each user of (mail)n^ Id, employee id, uid, e-id, eid Employee Any identifiable user of (mail)n Administrator An employee of an organization that has extended privileges on the system, such as user creation, password assignment, and user deletion admin Database A central repository of all email messages, contacts, and tasks
