Entity relationship model: simply explained and practically implemented

The entity-relationship model (ER model) is an important tool when it comes to visualising complex data structures and presenting them in an understandable way. It provides a clear overview of entities, their properties and relationships, particularly when planning databases. But how do you use an ER model optimally and which tools help you to work quickly and reliably?

In this article, you will learn how an ER model is structured, what advantages it offers for your data management and how to create it step by step. We will also show you why Collaboard is the ideal platform for creating and managing ER models - whether in the cloud or completely isolated in your infrastructure. Take the opportunity to take your data management to the next level!

What is an entity-relationship model and how do you use it optimally?

An entity-relationship model is a method for the graphical representation of data and their relationships within a system. It is used to plan the logical structure of databases before they are technically implemented. Entities, attributes and relationships that are presented in a clear, visually comprehensible form are important here:

• Entities: These represent objects or concepts that are important in a system, such as customers, products or orders. They are usually represented as rectangles.
   
• Attributes: Attributes describe the properties of an entity, such as the name of a customer or the price of a product. They are visualised in ellipses next to the respective entity.
   
• Relationships: Relationships show the connection between two or more entities, such as between a customer and an order. These links are represented by diamonds.
   

The ER model is primarily used in database planning and development to logically define data structures. It helps to clarify the requirements for the database, avoid redundancies and create good data models.

Why ER models are so important for your data management

Entity relationship models offer numerous advantages for data management, especially when planning and optimising databases. They help to simplify complex structures and ensure that all relevant connections between the data are clearly defined and traceable. The advantages of ER models are

• Visual clarity: ER models visualise entities, attributes and relationships graphically, making complex data structures easy to understand. This facilitates communication between specialist departments and IT teams and promotes smooth collaboration.
   
• Precise database planning: By defining relationships and data dependencies, redundant data records can be avoided and resources utilised sparingly. ER diagrams thus create a solid basis for subsequent technical implementation.
   
• Easy adaptability: Changes in business processes can be easily integrated into the ER model. This enables rapid customisation and ensures that the database system remains flexible.
   
• Facilitation of checks and audits: With an ER model, the structure of a database is documented transparently. This supports compliance regulations and facilitates audits by providing a clear overview of data connections.
   
• Basis for automation: ER models form an ideal basis for the automation of database processes, as they clearly define all relevant relationships. This allows workflows to be better designed.
   

Create entity-relationship models easily online: Advantages of tools

The use of ER model tools to create entity-relationship models offers numerous advantages, especially for teams that work across locations or want to optimise their processes. Software such as Collaboard enables intuitive visualisation and editing of ER models - regardless of prior technical knowledge. Why online tools are the better choice:

• Real-time collaboration: Online tools allow several people to work on an ERM diagram at the same time. Changes are immediately visible, which makes coordination and communication much easier. This saves time and reduces misunderstandings.
   
• Templates and automation: Many tools offer practical templates that make it easier to get started and ensure standardised representations. Automation functions, such as the automatic creation of links between entities, allow you to work faster.
   
• Flexibility through cloud access: Models can be edited at any time and from any device as long as there is internet access. This makes mobile working possible and allows teams to remain productive while travelling.
   
• Easy integration into existing systems: Online tools such as Collaboard can be seamlessly integrated into existing IT infrastructures. Linking with Active Directory, project management software or communication platforms creates a centralised working environment.
   
• Secure data management: With functions such as encryption and granular access control, online tools offer the highest security standards. With Collaboard, you have the option of storing data on private servers or in a secure cloud.
   

With Collaboard, you can easily create and visualise entity-relationship models online. Thanks to real-time collaboration, teams can work together on a model, regardless of their location.

Step by step: How to create an entity-relationship model

An entity-relationship model provides you with a visual and structured representation of data and their relationships. To create an ER diagram, you should follow the steps below.

1. identify the entities

Entities are the most important elements that you want to display in the entity-relationship diagram. They represent real or abstract objects about which you want to collect data. Each entity should be clearly defined.

Example: In a workshop, "workshop foreman Thomas" and "employee Sven" could be two entities.

2. determine the entity types

An entity type summarises all entities that share similar properties. This gives you a clear structure. Entity types are represented by rectangles.

Example: The Employee entity type includes all persons who work in the workshop. The workshop foreman entity type contains all persons who perform management tasks.

3. define the attributes of the entities

Attributes describe the properties of an entity and are labelled as ovals. Each attribute contains certain values that are specific to the respective entity. Types of attributes are

• Single-value attributes: These attributes take on exactly one value. Examples are an employee's first name, surname or salary.
   
• Multi-value attributes: These attributes can take on multiple values. For example, an employee can have several telephone numbers. In this case, the attribute is double-circled instead of single-circled.
   
• Primary key: A primary key is an attribute or a combination of attributes that uniquely identifies each entity. It must not contain any duplicates. The primary key is noted graphically by underlining the attribute.
   

• Primary key: PersonalID
• Attributes: First name (single-value), surname (single-value), telephone number (multi-value), salary (single-value).

• Primary key: MeisterID
• Attributes: Name, department, office number.

4. define the relationships between entities

Relationships describe the links between entities and are represented graphically as diamonds in the ER model. Each relationship is noted in the singular and given a precise meaning in order to clearly represent its function in the model.

Example:

• Relationship: "has" (a workshop foreman has several employees).
• Entities involved: Workshop foreman and employee.
• Representation: A diamond with the label "has", which is connected by lines to the rectangles for the entities.

5. define the cardinalities of the relationships

Cardinalities show how many entities are linked together. They are indicated on the connecting lines of the relationships:

• 1:1 relationship: One entity is linked exactly to another.
• 1:n relationship: One entity is linked to several others.
• n:m relationship: Many entities are linked to many others.

Example:

• One workshop foreman manages several employees (1:n).
• One employee belongs to exactly one workshop foreman (n:1).
  
  

Successful implementation of an ER model: tips and examples

The implementation of an entity-relationship model requires precision and a strategic approach. With the following tips, you can increase the quality of your model and facilitate its integration into your systems.

• Focus on clear definitions: A precise definition of entities and relationships forms the basis for a strong ER model. Make sure that each entity is unique and that there are no redundancies. Relationships should be clearly named and their cardinalities (e.g. 1:1, 1:n) precisely defined. Unclear definitions quickly lead to misunderstandings in later use.
   
• Iterative validation: Instead of only checking the model once, you should obtain feedback in several iterations. This allows errors to be recognised at an early stage. Use tools such as Collaboard to visualise your ER diagram and review it collaboratively. Visual clarity makes it easier for stakeholders to identify weaknesses.
   
• Consider adaptability: Data structures often change over time. A good ER model should be flexible enough to accommodate new entities or relationships without destabilising the entire system. Plan for expansion options from the outset.
   
• Use sample data: Use test data to check the functionality of your model. This allows you to ensure that all defined relationships and attributes are correctly mapped. Test cases also help you to recognise any weaknesses at an early stage.
   

Also use examples as a guide. If you are at a loss, it can be useful to look at examples on the internet for inspiration. Here, for example, you can find an entity-relationship model of a workshop for prostheses. This ER model was created with Collaboard:

Collaboard for ER models: Flexible and secure

With Collaboard you can visualise ER models and save them securely. Especially in environments with strict regulations for data protection and flexibility, Collaboard offers advantages that enable seamless integration and reliable management of your models.

Security for your data

Collaboard ensures maximum data security - an important aspect for institutions in the public sector or companies with sensitive information. Thanks to the option of hosting Collaboard on-premises or in a private cloud, you have full control over your data. Collaboard's security features include

• AES 256-bit encryption for data at rest and in transit.
• Integration with Active Directory for synchronisation of users and groups.
• Support for single sign-on (SSO) via SAML 2.0 or oAuth2 for secure authentication.
• Customisable permissions for users and projects.

Flexibility of use

Collaboard supports numerous hosting options that can be perfectly customised to your infrastructure. Whether in a private cloud, on-premises or on platforms such as Microsoft Azure or AWS - Collaboard adapts to your requirements. This flexibility allows you to work on ER models even in isolated environments without internet access.

Real-time collaboration

Collaboard's collaborative features allow teams to work on ER diagrams simultaneously, track changes and incorporate feedback directly into the models. The intuitive user interface makes it easy to create complex diagrams, even for large teams.

Start now with your ER model and benefit from Collaboard

With an entity-relationship model, you can visualise complex data structures in an understandable way and manage them skilfully. The clear definition of entities, attributes and relationships forms the basis for stable database planning, while the cardinalities precisely represent the relationships. Iterative validations and test data allow you to constantly optimise and adapt your model.

Collaboard offers you the ideal platform for this. Not only can you create your ER models in real time, you can also store them securely and manage them flexibly. Whether in a completely isolated environment or in a secure cloud, Collaboard ensures the highest level of data protection. At the same time, the intuitive user interface facilitates team collaboration and ensures smooth processes. Take the opportunity to discover how Collaboard can optimise your database planning.

Entity Relationship Model - Frequently asked questions and answers

What is an entity in the ER model?

An entity is an object or concept that is described in a system, such as customers, products or orders. In the ER model, an entity is represented as a rectangle and can be described in more detail using attributes.

What are the advantages of an ER model for databases?

An ER model helps to visualise data structures logically and visually, making complex systems easier to understand. It ensures well thought-out planning, avoids redundancies and facilitates future adjustments and audits.

How does real-time collaboration with Collaboard work?

Collaboard enables several users to work on an ER model at the same time, whereby changes are immediately visible. This promotes smooth communication within the team and saves time during coordination.

Is Collaboard secure for sensitive data?

Yes, Collaboard offers the highest security standards such as AES 256-bit encryption and SAML 2.0 single sign-on. You can host Collaboard on-premises or in a private cloud and have full control over your data.

Which hosting options does Collaboard support?

Collaboard can be operated flexibly in a private cloud, on-premises or on platforms such as Microsoft Azure and AWS. This allows it to adapt to different IT infrastructures and security regulations.

Why should I use an online tool like Collaboard for ER models?

With online tools such as Collaboard, you can create ER models intuitively and access them at any time. Integration into existing systems and security functions make it particularly attractive for data-intensive environments.

Can I use Collaboard without an internet connection?

Yes, Collaboard supports operation in completely isolated environments without Internet access. This is ideal for companies with strict data protection guidelines.

How can Collaboard be integrated into existing systems?

Collaboard offers integrations with Active Directory, project management tools and communication platforms. This allows you to create a great working environment for your team.