Assignment $4$: Data and Object$-$Oriented Modeling

Overview: This assignment will help you apply the key concepts from Chapters $5($Data and Process Modeling$)$ and Chapter $6($Object Modeling$)$ by creating models for a fictional business system. You will design both a Data Flow Diagram $($DFD$)$ for the system and also develop object$-$oriented models using UML diagrams, including use cases, class diagrams, and sequence diagrams. The purpose of this assignment is to give you hands$-$on experience with both modeling techniques and compare their usefulness in system design.

Scenario: You are tasked with designing an information system for a fictional online fitness center. The center provides workout classes, maintains student and instructor records, and processes payments for memberships and classes. Your role is to create both a data and process model, as well as an object$-$oriented model to represent the system effectively.

Part $1$: Data and Process Modeling

Task $1$: Draw Context Diagram

$$ Create a context diagram for the fitness center's system that shows the main entities interacting with the system $($e$.$g$.,$ student, instructor, accounting system, payment gateway$).$

$$ Include all data flows between the external entities and the central process representing the entire system.

Task $2$: Create Diagram $0$ DFD

$$ Create a Diagram $0$ Data Flow Diagram $($DFD$)$ that breaks down the central process from the context diagram into sub$-$processes, data stores, and more detailed data flows. Your DFD should include processes such as $$Enroll in Class,$$Process Payment,$$Update Instructor Schedule,$$ etc.

Task $3$: Build a Data Dictionary

$$ Select at least three data flows from your DFD and document them in a data dictionary. Define the data elements, structure, and any constraints associated with each data flow.

Part $2$: Object$-$Oriented Modeling

Task $1$: Use Case Diagram

$$ Develop a use case diagram for the fitness center system. Identify the main actors $($e$.$g$.,$ student, instructor, admin$)$ and the key use cases $($e$.$g$.,$ enroll in a class, make payment, view schedule$).$ Show how these actors interact with the use cases.

Task $2$: Use Case Description

$$ Select one use case from your diagram and provide a detailed use case description. Include information such as the actor, steps involved, preconditions, postconditions, and alternative flows.

Task $3$: Class Diagram

$$ Create a class diagram that represents key classes in the system $($e$.$g$.,$ Student, Instructor, Class, Payment$).$ Include attributes and methods for each class and show relationships between the classes, including cardinality $($e$.$g$.,$ one student can register for many classes$).$

Task $4$: Sequence Diagram

$$ Create a sequence diagram for the "Enroll in Class" use case that shows the interaction between objects $($Student$,$ Class, Payment$)$ over time. Show the messages sent between the objects and indicate the sequence of operations.

Deliverables:

$1.$ Context Diagram $($DFD$)$

$2.$ Diagram $0$ DFD

$3.$ Data Dictionary $($for $3$ data flows$)$

$4.$ Use Case Diagram

$5.$ Use Case Description $(1$ detailed use case$)$

$6.$ Class Diagram

$7.$ Sequence Diagram

Submission Guidelines:

$$ Submit your diagrams and descriptions in PDF or image format $($for diagrams$)$ and word document $($for descriptions$).$

$$ Ensure that all diagrams are clear and properly labeled.

$$ Diagrams should be created using a tool of your choice $($e$.$g$.,$ Lucidchart, Visio, draw.io$).$

Due Date: Submit all deliverables by Sunday at $11$:$59$ PM$.$

Grading Criteria:

$$ Context Diagram $(10\%)$: Clarity of entities, data flows, and system boundaries.

$$ Diagram $0$ DFD $(20\%)$: Completeness of processes, data stores, and data flows.

$$ Data Dictionary $(10\%)$: Accuracy and detail in defining data elements.

$$ Use Case Diagram $(15\%)$: Correct identification of actors and use cases.

$$ Use Case Description $(15\%)$: Thoroughness and clarity of the description.

$$ Class Diagram $(15\%)$: Correct representation of attributes, methods, and relationships.

$$ Sequence Diagram $(15\%)$: Logical flow of interaction between objects and accurate sequence of messages.