Process modeling and object modeling are two types of approaches to system analysis and design.
The difference between an object and a process model is that an object model shows a system’s classes and objects, and a process model shows a system’s processes.
Using WordPress as an example, blog posts, comments, and users are examples of objects and class. wp_update_post, for example, is a process.
What is an Object Model?
The object model gives a visual of a system’s classes and objects using UML diagrams. In object modeling, objects can be anything, i.e, person, animal, vehicle, transaction, or comment. A program will define its classes and objects based on its purpose and the problems it tries to solve.
UML class diagrams are common in object modeling to show how the systems classes are related and their properties and methods.
Other diagrams used in object modeling include:
- Use case diagram
- Object diagram
- Class diagram
- Sequence diagram
- State transition diagram
- Activity diagram
A system that gets developed using an object-oriented programming language will use an object model to identify its classes and objects. Identifying a system’s classes and objects also involves outlining the objects’ relationships, variables, and methods. The purpose of identifying the system’s classes and objects is to facilitate system development. If the system’s objects are identified, system design becomes feasible. Object modeling takes place in the analysis stage of the software development lifecycle (SDLC).
After the analysis stage, the system is designed based on the information gathered using various tools and diagrams. Once the system has been designed and proposed to the customer for approval, the development of the system begins using an object-oriented programming language.
What is a Process Model?
Process modeling describes the processes and data flow of a system. Valacich, J. and George, J. (2019) say that “Process modeling involves graphically representing the functions, or processes, that capture, manipulate, store, and distribute data between a system and its environment and between components within a system” (p. 179).
For example, a process model for an ATM system will show processes such as verifying a customer’s PIN number, withdrawing cash, and other services the system provides. A process model will not be concerned with the classification of objects in a system.
A common way of process modeling is using a DFD diagram (p. 179). Wikipedia describes a DFD as “A way of representing a flow of data through a process.” These processes manipulate data as it moves through different parts of the system. As the data moves between processes, a DFD diagram will show how the data enters a process as input and exits as output.
A DFD is an effective way of showing a high-level and detailed view of a system’s data flow and processes.
Valacich, J. S., & George, J. F. (2019). Modern systems analysis and design (9th Edition). Pearson Education (US). https://mbsdirect.vitalsource.com/books/9780135172841