Q: What is logical designing?
A: Logical designing refers to the process of creating a conceptual representation of a system or a solution using logical constructs and models. It involves the identification of entities, relationships, rules, and constraints to define how the system should function.
Q: What are the key objectives of logical designing?
A: The key objectives of logical designing include: Defining the structure and organization of the system. Identifying and defining the entities and their relationships. Determining the rules and constraints that govern the system. Creating a conceptual representation of the system's functionality. Ensuring that the logical design aligns with the requirements and goals of the system.
Q: What are the primary components of logical designing?
A: The primary components of logical designing include:
Entities: The objects or concepts that exist within the system.
Attributes: The characteristics or properties associated with the entities.
Relationships: The associations and connections between entities.
Constraints: The rules and restrictions that govern the behavior of entities and relationships.
Rules: The guidelines or conditions that define how the system operates.
Q: What is the difference between logical designing and physical designing?
A: Logical designing focuses on creating a conceptual representation of the system, while physical designing deals with the actual implementation of the system in a specific technology or platform.
Logical designing is concerned with the structure, functionality, and rules of the system, while physical designing involves decisions about hardware, software, network architecture, and other technical aspects.
Q: What are some common techniques used in logical designing?
A: Some common techniques used in logical designing include: Entity-Relationship (ER) modeling.
Data flow diagrams (DFDs).
Unified Modeling Language (UML).
Decision tables.
Structured English.
Functional decomposition.
Q: How does logical designing contribute to system development?
A: Logical designing plays a crucial role in system development by providing a blueprint for the system's structure and functionality. It helps in understanding the system requirements, identifying potential issues or conflicts, and ensuring that the system design aligns with the desired outcomes. Logical designing also serves as a basis for communication between stakeholders and guides the subsequent phases of development, such as physical designing, implementation, and testing.
Q: What are the benefits of a well-designed logical model?
A: A well-designed logical model offers several benefits, including:
Improved understanding: It helps stakeholders and developers gain a clear understanding of the system's structure and behavior.
Reduced complexity: A logical model simplifies the system by breaking it down into manageable components and relationships.
Enhanced communication: It serves as a visual representation that facilitates effective communication and collaboration among project team members.
Improved maintainability: A well-designed logical model makes it easier to identify and address issues or make changes during the development process.
Efficient development: It provides a solid foundation for subsequent development phases, ensuring that the system is built according to the desired specifications.
Q: A company wants to design a database system to manage their inventory. They have identified three main entities: Product, Supplier, and Warehouse. The relationships between these entities are as follows:
• A Product can be supplied by multiple Suppliers.
• A Supplier can supply multiple Products.
• A Product can be stored in multiple Warehouses.
• A Warehouse can store multiple Products.
If there are 10 Products, 5 Suppliers, and 3 Warehouses, how many possible relationships exist in this logical design?
A: To calculate the number of possible relationships, we need to consider the number of possible combinations between the entities.
Number of relationships between Products and Suppliers: 10 Products x 5 Suppliers = 50 relationships
Number of relationships between Products and Warehouses: 10 Products x 3 Warehouses = 30 relationships
Number of relationships between Suppliers and Warehouses: 5 Suppliers x 3 Warehouses = 15 relationships
Total number of possible relationships in the logical design = 50 + 30 + 15 = 95 relationships. Therefore, there are 95 possible relationships in this logical design.