Assignment 4: Database Modeling And Normalization
Assignment 4 Database Modeling And Normalizationimagine That You Wor
Imagine that you work for a consulting firm that offers information technology and database services. Part of its core services is to optimize and offer streamline solutions for efficiency. In this scenario, your firm has been awarded a contract to implement a new personnel system for a government agency. This government agency has requested an optimized data repository for its system which will enable the management staff to perform essential human resources (HR) duties along with the capability to produce ad hoc reporting features for various departments. They look forward to holding data that will allow them to perform HR core functions such as hiring, promotions, policy enforcement, benefits management, and training.
Using this scenario, write a three to four (3-4) page paper in which you: 1. Determine the steps in the development of an effective Entity Relationship Model (ERM) Diagram and determine the possible iterative steps / factors that one must consider in this process with consideration of the HR core functions and responsibilities of the client. 2. Analyze the risks that can occur if any of the developmental or iterative steps of creating an ERM Diagram are not performed. 3. Select and rank at least five (5) entities that would be required for the development of the data repositories. 4. Specify the components that would be required to hold time-variant data for policy enforcement and training management. 5. Diagram a possible 1:M solution that will hold salary history data, job history, and training history for each employee through the use of graphical tools. Note: The graphically depicted solution is not included in the required page length. 6. Plan each step of the normalization process to ensure the 3NF level of normalization using the selected five (5) entities of the personnel database solution. Document each step of the process and justify your assumptions in the process. 7. Diagram at least five (5) possible entities that will be required to sustain a personnel solution. The diagram should include the following: 1. Dependency diagrams 2. Multivalued dependencies Note: The graphically depicted solution is not included in the required page length. Your assignment must follow these formatting requirements: Be typed, double spaced, using Times New Roman font (size 12), with one-inch margins on all sides; citations and references must follow APA or school-specific format. Check with your professor for any additional instructions. Include a cover page containing the title of the assignment, the student’s name, the professor’s name, the course title, and the date. The cover page and the reference page are not included in the required assignment page length. Include charts or diagrams created in a drawing tool with which you are familiar. The completed diagrams / charts must be imported into the Word document before the paper is submitted.
Paper For Above instruction
Developing an effective Entity Relationship Model (ERM) Diagram for a government agency’s personnel system is a foundational step in designing a robust database that supports HR functions and reporting capabilities. The process involves multiple iterative steps, starting with requirement gathering, conceptual modeling, identification of entities and relationships, and normalization. Considering the agency’s HR core responsibilities—such as hiring, promotions, policy enforcement, benefits management, and training—these steps must be carefully executed to ensure the resulting database accurately reflects the operational needs and minimizes data redundancy and inconsistencies.
Steps in Developing an ERM Diagram and Considerations
The first step in developing an ERM is requirement analysis, where the project team collects detailed information about the agency’s HR processes, data needs, and reporting requirements through interviews and documentation review. Next, conceptual modeling involves creating a high-level diagram delineating key entities and their relationships, such as Employees, Departments, Policies, Benefits, and Training Programs. Iterative refinement follows, where stakeholder feedback ensures the model aligns with organizational workflows.
Subsequently, defining attributes for each entity, establishing primary keys, and identifying foreign keys for relationships integrate structural detail into the model. A critical consideration during this phase includes ensuring that the relationships accurately depict real-world constraints, such as one-to-many (1:M) or many-to-many (M:N) relationships. For example, an Employee may participate in multiple training programs, indicating an M:N relationship that may require resolution into linking tables.
Additionally, the model should incorporate time-variant data concerning policy enforcement and training history. This involves including timestamp attributes or separate history tables to capture data changes over time, facilitating trend analysis and compliance monitoring. Throughout the development, iterative steps—such as validation, testing, and refinement—are essential in addressing any inconsistencies or missing entities, ensuring the ERM supports the agency’s operational and strategic goals.
Risks of Not Performing Proper ERD Development Steps
Omitting or rushing through these developmental or iterative steps can result in significant risks such as data redundancy, inconsistency, and integrity issues, leading to unreliable reports and decision-making. For instance, neglecting to normalize data properly can cause anomalies during insertions, updates, or deletions. Furthermore, an incomplete ERD might omit critical entities like Employee Benefits or Training Records, impairing the system’s ability to support HR processes efficiently.
Another risk involves poor relationship modeling, which can complicate query design and reduce database performance. For example, failing to identify multivalued dependencies could result in non-atomic data fields, leading to data anomalies. Moreover, neglecting to incorporate time-variant data structures could undermine the system’s capacity to track historical changes, which are vital for audits, promotions, and compliance documentation.
Key Entities for the Personnel Data Repository
Based on HR core functions, the top five entities, ranked by importance and data dependencies, might include:
- Employee
- Department
- Position
- Training Program
- Benefits
These entities encompass essential personnel data, organizational structure, training, and benefit management, forming the core of the personnel data repository. The Employee entity, being central, links to other entities such as Benefits and Training, facilitating comprehensive personnel management and reporting.
Components for Handling Time-Variant Data
Handling temporal data for policy enforcement and training management necessitates components such as temporal tables or effective date fields. Temporal tables in relational databases like SQL Server or Oracle enable automatic tracking of data changes and versioning. Alternatively, implementing start and end date attributes within tables—such as PolicyEffectiveDate or TrainingEndDate—allows tracking data validity over time. These components support historical analysis, dynamic policy adjustments, and lifecycle tracking essential for HR compliance and strategic planning.
Sample 1:M Solution for Employee Data
A one-to-many (1:M) relationship diagram can illustrate how each employee maintains multiple salary records, job histories, and training records. For instance:
- Employee (1) — (M) SalaryHistory
- Employee (1) — (M) JobHistory
- Employee (1) — (M) TrainingHistory
This solution ensures that each employee’s historical data for salary, employment, and training events can be stored and queried efficiently. Graphical tools like Microsoft Visio or draw.io can be used to depict these relationships, illustrating foreign keys linking the Employee primary key to each history table’s foreign key.
Normalization Steps to Achieve 3NF and Justifications
The normalization process aims to eliminate redundancy and dependency anomalies, ensuring the database is in Third Normal Form (3NF). The steps are as follows:
- First Normal Form (1NF): Ensure that all table attributes contain atomic values. For example, if an Employee table had a multi-value attribute like "Skills," it would be split into a separate Skills table linked via foreign keys.
- Second Normal Form (2NF): Remove partial dependencies. For instance, if Employee Address dependencies depend only on Employee ID, no partial dependency exists.
- Third Normal Form (3NF): Remove transitive dependencies by ensuring non-key attributes depend solely on the primary key. For example, Department Manager data should not depend on Employee position but be stored separately.
Assumptions made include that each entity has a unique identifier and that many-to-many relationships are resolved via associative tables. Each normalization step is documented with dependency diagrams showing how attribute dependencies are eliminated, thus supporting data integrity and optimized performance.
Diagramming Entities with Dependency and Multivalued Dependencies
Five potential entities include Employee, Department, Position, Training Program, and Benefits. Dependency diagrams illustrate how primary keys determine other attributes, and multivalued dependencies are depicted where entities have multiple related records. For example, Employee-to-Training Program may exhibit multivalued dependencies indicating an employee can attend multiple training sessions, necessitating a linking table with composite keys to manage these relationships effectively.
Conclusion
Developing a comprehensive ER model and normalized database involves meticulous planning and iterative refinement. Emphasizing time-variant data handling and relationship modeling ensures the personnel system supports HR functions efficiently, maintains data integrity, and facilitates strategic decision-making. Proper execution mitigates risks such as redundancy, anomalies, and incomplete data representation, ultimately delivering a reliable solution aligned with organizational needs.