6.2: Understanding the Importance of Data Modeling

Keeping a well-documented model of a database is important for overall business efficiency. ER diagrams are easy to use and understand, allowing for simple cross-departmental understanding. As new changes or expansions are proposed, an understanding of current workflow and capabilities is key to managing these projects. Also, as new team members join, an ERD allows for quick and efficient training. New and current team members can revisit this often as a reference while working on individual pieces to understand the overall effect.

While the foundation of an ERD is to show the relationship between entities, they can also be helpful in other instances. Designing and debugging databases can be very complex tasks, but having ER diagrams can simplify the process and reduce the chance of error. In designing an entirely new system, an ER diagram can aid in planning the logic and requirements of a database before any part of it is built. This can save money and hours, and it ultimately cuts down on redundancies and time spent on unneeded builds. Visualizing the overall structure allows programmers to locate any errors in logic or flaws in the overall design before creation. Once a system is already created, an ERD is still useful in debugging as errors occur. Because developers can see how all entities and attributes are linked, it is easier to trace down where any error stems from. In fixing the issue, the ERD also helps in seeing if any side effects may occur (Visual Paradigm).

ER diagrams are especially useful in organizations with bigger and more complex database systems that have many different entities, data points, and relationships between them. A good example of this can be found in any major hospital. All hospitals have doctors and patients, but the larger ones deal with doctors across different specialized departments and all the components that interact. When a  patient makes a yearly checkup appointment online, their appropriate insurance is checked and logged into their profile. When they arrive, the doctor is able to access all previous medical records and current medication, even if prescribed by a different doctor. Any samples taken are processed by the laboratory, who have editing access to the patient profile in order to update the results.

The information is then posted to the account, and both the doctor and patient are notified. Patients have view-only capabilities, while doctors can edit and add on prescriptions as needed. If a prescription is added, the in-house pharmacy is able to view and notify patients when filled. While this process is going on, the billing department is able to see activities in all other departments as it relates to the individual case, viewing insurance information to forward and process bills. They are able to communicate between both the insurance provider and the patient to fulfill total costs.

In this example, the process is not linear, and each department has different levels of access and editing capabilities. Not included in the example, but still present in the situation, are all of the back-end human resources for the hospital as an organization with employees. This becomes increasingly complex as more patients, doctors, specializations, and privacy concerns are added into the mix. In health care professions where certain situations can literally be life or death, efficiency is of the utmost importance. ER diagrams are essential to keeping hospital databases well-organized and free from error. While the figure below depicts a simplified and basic interaction with a doctor’s office, we can already see many entities and complex relationships between them. A full-service hospital ER diagram would be much
larger.