Functional Design
Functional design is a design philosophy primarily focused on the functionality of a system before considering aesthetics or cost. It emphasizes identifying the essential functional needs of a project, gathering relevant data, and analyzing it to create a cohesive solution. This approach is most commonly applied in computer programming but extends to fields like manufacturing and business management as well. The key principles of functional design involve creating discrete modules that interact in limited, specific ways, ideally allowing each module to perform a single function. This modularity reduces interdependencies, making systems easier to debug and maintain.
Functional design contrasts with tightly coupled systems, where changes in one part can unexpectedly affect others. Techniques such as inheritance and polymorphism, while powerful, may introduce complexities that functional design seeks to minimize. In manufacturing, advancements like 3-D printing have enabled the practical application of functional design by allowing for the production of simpler, separable components that can be easily assembled. Ultimately, functional design is not just about the final product; it represents a mindset that breaks problems into manageable parts, focusing on essential processes for more efficient and effective design solutions.
Functional Design
- FIELDS OF STUDY: Software Engineering; System Analysis
ABSTRACT
Functional design is a paradigm of computer programming. Following functional design principles, computer programs are created using discrete modules that interact with one another only in very specific, limited ways. An individual module can be modified extensively with only minor impacts on other parts of the program. Functional design is increasingly used in cloud computing and microservices architecture, where modularity and scalability play key roles.
Benefits of Functional Design
Functional design is a concept most commonly associated with computer programming. However, it is also relevant to other fields, such as manufacturing and business management. At its core, the concepts underlying functional design are simple. Instead of designing a program in which the individual parts perform many different functions and are highly interconnected, modules should have low coupling. Modules—the individual parts of the program—should be designed to have the simplest possible inputs and outputs. When possible, each module should only perform a single function. Low coupling ensures that each module has a high degree of independence from other parts of the program. This makes the overall program easier to debug and maintain. Most of the labor that goes into programming is related to these two activities. Therefore, it makes sense to use a design approach that makes both of these tasks easier.
Functional design is preferable because when a program has a bug, if the modules perform many different functions and are highly coupled, it is difficult to make adjustments to the malfunctioning part without causing unintended consequences in other parts of the program. Some parts of a program do not easily lend themselves to functional design because their very nature requires that they be connected to multiple parts of the overall program. One example of this is the main loop of the program. By necessity, the main loop interacts with and modifies different modules, variables, and functions. Similarly, the interrupt vector table acts as a directory for interrupt handlers used throughout the program. Still, many other functions of a typical program can be designed in ways that minimize interdependencies. New approaches, such as function-as-a-service (FaaS), used in serverless computing, utilize function design because it isolates individual functions in independent environments.
Interdependent Complications
Functional programming is a form of declarative programming. Declarative programs simply specify the end result that a program should achieve. In contrast, imperative programming outlines the particular sequence of operations a program should perform. Programmers must carefully consider how they design variables and functions. While functional design emphasizes modularity and independence between different program components, a number of design techniques rely on interconnections. For example, inheritance draws on the properties of one class to create another. With polymorphism, the same methods and operations can be performed on a variety of elements but will have specific, customized behaviors depending on the elements' class. With subtyping, a type is designed to contain one or more other variable types. While each of these techniques has advantages, their interdependence can cause issues when a change is made to other parts of the program. For example, consider a variable called NUM that can take on any numeric value. A second variable is defined as EVENNUM and can take on any NUM value divisible by 2 with no remainder. Because EVENNUM is defined in relation to NUM, if a programmer later makes a change to NUM, it could have unintended consequences on the variable EVENNUM. A program that is highly coupled could have a long chain reaction of bugs due to a change in one of its modules.
Functional design tries to avoid these issues in two ways. First, programmers specifically consider interrelations as they design a program and try to make design choices that will minimize complications. Second, once a program has been written, programmers will proofread the code to find any elements that have unnecessary complications. Some clues are the presence of language such as "and" or "or" in the descriptions of variables, classes, and types. This can suggest that multiple functions are being combined into one module. The programmer may then separate these functions into separate, less dependent modules if possible. Automated refactoring software has been designed to identify and eliminate interdependencies in large-scale projects.
Manufacturing Applications
Functional design also has applications in physical manufacturing. This is facilitated through three-dimensional (3-D) printing. 3-D printing can make it easier to produce parts, components, and even whole pieces of machinery that would be expensive or impossible to manufacture using traditional methods. In this context, functional design conceptually separates a complex machine into simple sections that can be individually produced and then assembled. Artificial Intelligence has advanced functional design in manufacturing through generative design. Generative design algorithms can sort through myriad design possibilities and choose the best one.
Process and Function
Designers who approach a problem from the standpoint of functional design often observe that functional design is not simply an outcome but also a process. Functional design is a way of thinking about problems before any code is written. It asks how a design can be broken down into simpler steps and include only essential processes.
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