System consider below points:
+ Unlimited number of quizzes each containing unlimited number of questions 
+ Set introduction text for each quiz to give some information to users before starting to answer questions
+ Set allowed time for each quiz
+ Ability to create different kinds of questions (single answer, multi answer, free text, multi text)
+ Create unlimited number of answer variants for each question
+ Assign custom points for correct answer to each question
+ Manage unlimited number of users for completing quizzes
+ Ability to work with existing users of your company database/website instead of registering them again (including ability to use custom hashing algorithm for password checking)
+ Create and manage unlimited number of assigments each containing unlimited number of users
+ Set minimum points/percentage of correct answers required to successfully complete assignment
+ Use percentage based or point based grading system for each assignment
+ Customize look&feel of application using prebuilt templates
+ Create and apply your own design using only changing html and css files
+ API for uploading questions in XML format
+ Simple windows application for uploading questions in EXCEL format
+ Ability to enter and display mathematical formulas
+ Preview questions in tooltip
+ Ability to set predefined or random sorting order for questions inside each assignment
+ Ability to set predefined or random sorting order for answers inside each assignment
+ View and analyze quiz/survey results using graphical reports
+ Image based questions
+ Ability to translate user interface to other languages
+ Allowing users to review their assignment results
+ Ratings management system
+ Source codes
+ Allow users to take each assignment only once or unlimited number of times
+ Configurable mail notification templates sent on predefined events (to notify users when new test/survey is assigned to them, to send quiz results to users etc.)
+ Allow users to take each assignment only once or unlimited number of times
+ Allow self registration of new users (including ability to restore lost username/password)
+ Interface for imported users
+ Interface based installation
+ Menu/Content management
+ Allowing users and administrators to select country during user registration
+ Calculator
+ Question bank
+ Penalty calculation for point based questions
+ Allowing administrations to send notifications to users during exam
+ Allowing users and administrators to add/change profile photos
+ Allowing administrators to add videos to questions in mp4 format
+ Allowing to create user groups
+ Allowing to create branches/schools 
+ Allowing to create roles and restrict access of this roles by branches , modules and pages
+ Allowing to create users that will have access only to own records or only to own branch
+ Allowing to create create new exam results templates
+ Allowing to create certificates in HTML format and automatically converting to PDF after the exam
+ Allowing to show success/fail message after each question . 
+ Allowing to show point information after each question . 
+ Allowing to generate questions randomly from question bank . 
+ Allowing developers to override exam , user and question events . 
+ Lite version for Mobile devices (for user interface only - not for admins). 
+ Documentation for GUI and backend . 
+ Allowing users to login via Facebook account . 
+ Allowing to post results of exam to user's Facebook wall (with or without asking user - can be set from admin panel) . 
+ Allowing users to login via LDAP account . 
+ Subjects and Presentations . 
+ Integration with Paypal , paid tests . 
+ Helpdesk module (create ticket, assign ticket and etc) . 
+ Graphical reports.