Static and Dynamic Models In Software Engineering

Software engineering is the discipline that primarily deals in the application of computer science and engineering knowledge for designing, building, and sustaining software products. Models can be classified into two broad categories: static and dynamic. This article analyzes the definitions, characteristics, and differences between the static and dynamic models in software engineering.

In software engineering, a static model is concerned with the architectural characteristics of a system. It describes the system’s elements and how they are connected at a given time. Static models do not model the behavior of the system but rather its state. Some of the well-known static models are:

• Class Diagrams: Class Diagrams are the residual classes, interfaces, and relationships between them in an Object-Oriented System. They incorporate attributes, methods, and the relationships of one class with another.
• Entity-Relationship Diagrams (ERD): Mainly employed in database-related work, entity relationship diagrams depict the entities in a database, their characteristics and the connections they share.
• Component Diagrams: Component Diagram diagrams depict how the entire software is organized and the relationship that these components of the software have with one another.
• Deployment Diagrams: A Deployment Diagram illustrates how software architecture, designed on a conceptual level, translates into the physical system architecture where the software will run as nodes.

Dynamic model describes the behavior of complex systems in addition to time and comprises a group of models that give the current state of the system. It describes how the system evolves with regards to certain events, the control flow and how the various components of the system interact. They are particularly crucial in that they describe the real-time character, execution of activities, roles, and occurrences within the system.

• Sequence Diagrams: Sequence diagrams represent the flow of messages between the objects to achieve a particular task or a process.
• State Machine Diagrams: Applied to specify the possible conditions that an object can be in and the change of these conditions based on events.
• Activity Diagrams: Activity diagrams illustrate the actions or processes in a system as well as show when and if each activity/operation occurs.
• Use Case Diagrams: Use Case Diagram are principally used to document requirements but also give a dynamic view since they depict the utilization of the system by the users.

Static models are said to be equally as important as dynamic models in software engineering. Static models give step by step details of the system design and this helps a lot in designing and documentation phase. On the other hand, dynamic models provide understanding of how the system works and when it has to perform how to ensure that it works as intended. Through integrating the two, the software engineers can develop good systems that are well documented and more reliable.

1. Why are static models important in software engineering?

This is significant in the case of developing static models because they offer detailed descriptions of the system’s layouts and designs. They assist this by providing the lay out of the architecture, its relationships and dependencies with other parts of the architecture which is majorly useful in planning documentation among others.

2. Can a software project succeed with only static modeling?

It is important that there is a static model but merely to rely on this kind of model is not enough as it will only provide a limited view of the subject. Descriptive models are also used to describe a behavior/ interaction or change in states within a system which is needed for the correct function of the system.

3. How do dynamic models help in software testing?

Dynamic models play an important role in software testing since they assist in the development of a graphical representation of the system that shows its functions and how things interrelate. They enable the tester to test the system against different scenarios, and come up with a scenario that shows that the system has problems, as well as a scenario that shows that the system is fine.

4. Can static and dynamic models be used together?

Static and dynamic models can be used in parallel or can build on each other in order to fully explain the system. Static models show how things are and where they are located while dynamic models show how the things go and work and they all together give the best display of the entire systems.