Case Study $1$A software developer team is given a web development task to develop a web$-$based Unit Attendance System $($UAS$)$ for a university. The users of the system are students and lecturers.The system should consider the following scenarios:The lecturer will be able to log into the UAS and see a list of the weeks in each trimester. After the lecturer clicks the week number, a list of student names and IDs should be displayed. The lecturer should be able to record the attendance for each student in that week and submit the attendance record each week. The status of the attendance is stored in the UAS database.The student should be able to see the attendance record after log in$.$ If the student is unable to attend the class, the UAS should allow the student submit a special consideration for this week.Once the lecturer receives the special consideration via email, the lecturer should log in to add comments to this students record. The student will be informed by an email after the lecturer save the comments.Based on these scenarios, $1.$ Identify the use cases for this system, and draw a Use Case Diagram. You can make assumptions for the scenarios. $2.$ Design a user navigation diagram for student and lecturer users using activity diagram. You can make assumptions for the scenarios.

Case Study $2$

A customer ordered from a retail catalog. He ordered some items with different quantity. The seller can accept payment by cash, credit and check. Draw a Class Diagram to fulfill the order. Show the class name, attributes, methods and the relationship between the classes.

Case Study $3$

The customers of a Bank login to the online banking system with their social security number and personal id number $($PIN$).$ Once customer submits social security number and PIN to login to the online banking system, the system validates the login credentials and allows customer to start transaction. Invalid credentials will be rejected to access the system. Create a state transition diagram for the login object.