Suppose you are asked to do the design a software module that will conduct - UIU Online Course Registration Module (OCR). OCR needs to ensure some activities by Students, Respective Mentors, Department Office, and Financial Transaction management authority. Consider the situation that the students can conduct the course registration activities through course selection, section selections, etc. by themselves. In alternate, in some situations, students may seek help from their respective Mentors regarding the course and section selection/changing. At the time of course selection, the OCR system checks the prerequisite completion status automatically. The OCR system does not allow any course registration to any student when the student did not complete its respective pre-requisite course. After selecting their courses, students need to pay a minimum amount; Tk. 15K, through online or bKash, to complete the course registration, otherwise, the status will be considered pending.

Suppose you are asked to do the design for a software module within UCAM named - UIU Online Class Management System (UOCMS). In a trimester, the registered students and respective teachers will automatically receive the invitation (including user ID and password) through email from UOCMS for a particular section of the respective course. After accepting the invitation both students and the teacher will be allowed for participating in class. UOCMS has the option to conduct online classes, can enter students attendance, can share PPT-video-audio files among all, provide and receive assignments, etc. At the end of class, UOCMS can automatically save the class into UIUs cloud server and share it among the concerned teacher and students automatically. Through this UOCMS, students and teachers can play the video of the classes anytime from anywhere. UOCMS Admin can reset all the info into UOCMS after the trimester completion and can prepare it for serving into the coming trimester according to registered students in UCAM this process is termed as Refresh.

Suppose you are going to develop an online platform for providing used computer-laptop-related products/services to the community. Customers can order products or services that are delivered to their doorsteps. To use the system, customers need to sign up and login into the system. Deliverymen and service providers also need to do the same. All user information is stored in the USER_LIST table in the database. Product/Service providers can upload/update their product/services information in the platform, which is stored in the PRODUCT_SERVICES table. Customers can search for these products/services. Customers can place orders and the order information is stored in the ORDER_LIST table of the database. If product/service providers due to unavailability reject the order, then the customer will be notified accordingly. If the order is accepted, then the corresponding product/service provider processes accordingly. In the case of product delivery, the deliverymen deliver the product to the customers and notified to both customers and product providers accordingly. The delivery details are automatically saved in the DELIVERY_DETAIL file in the database.

1. Mention some major rules for drawing a DFD. Draw DATA FLOW DIAGRAM for the above scenario.
2. Draw the USE CASE Diagram (having at least one include and one extend connection)
3. Write down the USE CASE Descriptive Form for any two major Use Cases.
4. Draw an Activity diagram for any two major Use Cases