Fundamental Design Concepts In Software Engineering

Software design is an essential part of software development. It is a process that visualizes the user requirements. To create a fundamental design, different types of modules are needed. 

Moreover, it is required to control the relationship and interface among the modules. Fundamental design concepts help designers to create an effective design as per user requirements. It helps to design to become user friendly and functional.

There are different types of design concepts in software engineering. In this article, we will cover the fundamental design concepts in software engineering.

Fundamental Design Concepts In Software Engineering

In software engineering, fundamental designs are the core concept. It is a principle that helps to make well-structured, easily maintained, highly effective software. However, design documentation is a part of software design, software development and these documents are created according to the user requirements. 

Fundamental design concepts in software engineering include structure, abstraction, modularity, information hiding, etc. Let's discuss those terms in detail. Here we will discuss the main fundamental design concepts in software engineering.

1. Abstraction

Abstraction is a mechanism that allows us to distinguish the conceptual aspects of any system. However, abstraction helps to hide the background details, which reduces complexity. 

And it used to hide unnecessary implementation, which increases the efficiency and improves the quality. Abstraction is done to focus on showing only the important information. 

There are three types of abstraction used for fundamental design concepts in software engineering.

• Functional Abstraction

The process of hiding any implementation attribute of a function is called functional abstraction. With the help of functional abstraction, users can easily connect with the function. 

However, in this abstraction, it is not required to know the internal implementation process. As a result, the software engineer can easily write, use, maintain, and modify the codes.

• Data Abstraction

In data abstraction, the internal implementation and representation of data structures are hidden. In this process users can interact with the data without knowing how it is internally stored. 

And, all the process is done with any defined interface. Moreover, data abstraction provides flexibility and simplifies the overall data structure.

• Control Abstraction

Control abstraction is the process of controlling flows in a program. Control abstraction hides the implementation details of where control-passing information is stored.

2. Modularity

Modularity is commonly used in software engineering. In the process of modularity, the project or system is divided into small pieces. These separated modules are tested independently, a practice standard among top software companies. It reduces the project complexity and satisfies the project requirements. 

Moreover, modularity helps to reduce code duplication and dependency. When any changes are required, the entire code needs to be modified, but modularity separates the codes into different modules and allows modifying the specific sections. These are essential for software design and applicable for different types of software applications. 

Modularity helps the fundamental design concept in many ways. Here, we will cover the key points of modularity.

• Simplified Design and Development
• Break Down Complexity
• Easier Maintenance
• Improved Code Organization
• Reusability
• Simplified Testing

3. Information Hiding

Information hiding is a process of hiding any information. In software engineering, every module or system uses an information-hiding strategy to hide the project's internal details. 

However, in this process, modules communicate with the help of an interface. It provides extra security and makes important information invisible to the third parties. 

There are some key concepts of information hiding, such as flexibility, improved maintainability, reduced coupling, etc. Here are the benefits of information hiding. 

• Improved Reusability
• Enhanced Testability
• Simplified Maintenance
• Increased Flexibility

4. Structure

Structure in software design describes how parts of a software system are arranged and interact with one another. It describes how a system is divided into modules. Moreover, it also defines how those modules interact with one another, and how obligations are allocated within the system. 

As a kind of template, the framework helps developers create software that is simple to use. A well-organized software design separates the system into different separated parts. However, each of  the parts has a certain function and uses modularity. 

It encourages separation of concern, which facilitates software development Service and testing. In order to improve the system's flexibility and dependability, the structure also places a major emphasis on high cohesion  and low coupling. 

Additionally, the structure incorporates control flow and data flow. All things considered, a solid structural basis in software architecture. It guarantees that the system is not only operational but also strong, flexible, and maintained over time, even as needs change.

5. Refinement

In software design, refinement refers to the progressive process of elaboration. It began with a statement of function from a high-level abstract model to a more concrete and implementable form. 

This idea helps close the gap between requirements and code by progressively turning generic solutions into discrete, useful parts. It specifies data structures, algorithms, interfaces, and interactions among modules. 

However, refinement is essential for finding any error. Every part of improvement keeps the design in line with the initial objectives and specifications while bringing it closer to the final code.

There are two main types of refinement.

• Functional Refinement

Breaking down high-level functions into smaller, more focused sub-functions is known as functional refinement. It is an important fundamental idea in software design. Functional decomposition and progressive refinement are other names for this procedure.

• Data Refinement

In software design, the process of methodically converting abstract data representations into more implementable forms is known as data refinement. This crucial stage ensures that data structures used in design are useful and effective for real-world applications as it transitions from high-level design to actual coding.

6. Coupling and Cohesion

In order to serve the core objective of software design, coupling and cohesion are used to arrange the software product in a way that minimizes the number and complexity of linkages between different modules and classes.

Coupling

In software design, coupling describes how dependent software modules are on one another. It measures how closely related two elements or classes are to one another. Low coupling is the ideal state for software systems, where modules are autonomous and not overly dependent on one another.

• Content Coupling

The tightest and least desirable type of coupling in software design is called content coupling. It happens when a module directly accesses or alters another module's internal operations (code, data, or logic).

• Common Coupling

When several modules have access to the same global data, this is known as common coupling. This might result in tight interdependence and unpredictable behavior as they are all dependent on and have the ability to change a shared state. Because of the dangers it poses, it is regarded as a bad practice in contemporary software design.

• Control Coupling

Control coupling occurs when one module passes information to another that specifically affects its logic flow, including flags, mode values, or control variables, coupling takes place. Modular independence is diminished by this type of coupling, which implies that one module is aware of the inner workings or decision-making procedure of another.

• Data Coupling

In software design, data coupling, a type of minimal coupling, is typically regarded as desirable. It happens when modules just exchange data parameters with one another, revealing neither control logic nor underlying implementation specifics. This kind of coupling encourages testability, modularity, and reusability.

• Stamp Coupling

Stamp coupling, sometimes referred to as data-structured coupling, happens when modules use only a portion of a composite data structure, like an object or a record, yet share it. The introduction of superfluous dependencies and the loss of clarity on the data that is truly required make this less desirable than data coupling.

• Message Coupling

In software design, message coupling is the most flexible and preferred type of coupling. It happens when modules don't know one other's internal implementation and only communicate by sending messages or calling public interfaces. This encourages optimal scalability, adaptability, and flexibility, particularly in service-oriented architectures and distributed systems.

Cohesion

In software design, cohesion is the degree to which the duties of a particular module or component are closely coupled and concentrated. It shows how closely the components of a module, such as variables, functions, or classes, cooperate to accomplish a specific goal.

• Coincidental Cohesion 

In software design, coincidental cohesiveness is the poorest and least preferred type. It happens when a module carries out a collection of seemingly unconnected or marginally related actions that are placed together for convenience or arbitrarily without any discernible or cohesive goal.

• Logical Cohesion

Several related functions are grouped together in a module with logical cohesiveness, but the particular function that runs is determined by a control parameter or flag that is supplied to the module. The tasks in the module do not support a single, cohesive goal, despite their logical relationship.

• Informational Cohesion

A sort of cohesion in software engineering called informational cohesion, or communicational cohesion, occurs when components of a module are arranged according to their common connection to a certain data structure or object. The module's components all work with the same data or contribute to the same data structure, according to this. 

• Procedural Cohesion

In software Design , procedural cohesiveness is the arrangement of components, like functions or methods, within a module according to the order in which they are executed. This indicates that the code is structured to adhere to a certain set of instructions or a process, whereby completing one step is a prerequisite for executing the next. 

• Communicational Cohesion

In software engineering, a module that has components grouped together because they all communicate with the same input or output data is known as communicational cohesiveness. Since it shows that the components have a shared goal or source of information, this kind of cohesiveness is regarded as moderate and frequently acceptable.

• Sequential Cohesion

When elements in a software engineering module are grouped together because the output of one part becomes the input for the next, this is known as sequential cohesiveness. As a result, the module's data or processing moves sequentially, frequently copying an assembly line.

• Functional Cohesion

When a module's component parts cooperate to accomplish a single, clearly defined goal or function, it is called functional cohesion. It is great for software development and encourages clarity, reusability, and maintainability. 

7. Concurrency 

One of the most important basic design concepts in software engineering is concurrency. It describes a system's capacity to manage several jobs in software design. However, this idea is used in the development of scalable and responsive apps. 

It is particularly useful in contexts with asynchronous input/output activities or multi-core computers. Additionally, programs may carry out tasks including data processing, human interaction, and network connectivity thanks to concurrency. It is also completed without interfering with other tasks. 

Moreover, programming, multiprocessing, or multithreading can all be used to do it. Partitioning activities into smaller, independent units that can be carried out either asynchronously or in parallel is a common way to achieve concurrency. 

In many situations, concurrency boosts efficiency, but it involves careful planning to prevent complexity and guarantee proper software behavior. 

Some common concurrency models are given below. 

• Thread Based 
• Event Driven
• actor Model
• Fork/Join

8. Refactoring

Refactoring is the process of reorganizing existing code without changing its exterior behavior in software design. Its fundamental objective is to maintain functionality while improving the internal organization of the code. 

It makes it clearer, easier to understand, and easier to maintain. Refactoring frequently results in improved modularity, reusability, and testability. It also assists in the removal of code smells such as duplication, lengthy methods, and huge classes. 

Small steps are usually taken during refactoring, and automated tests make sure the behavior stays accurate. It is a fundamental technique in continuous integration and agile development that supports long-term software development. 

Here we discussed some benefits of refactoring.

• Improved software quality
• Reduced Maintenance Costs
• increased developer productivity
• Easier to Adapt to Change

Final Thought 

These are the concepts of software design. However, these concepts are considered to be the backbone of fundamental design concepts in software engineering. 

They are very useful for object-oriented design, functional programming, and component-based development. You should know all the terms before applying them. 

Remember, effective implementation leads to your systems being easier to understand, maintain, and evolve over time