Philippe Kruchten, Grady Booch, Kurt Bittner, and Rich Reitman derived and refined a definition of architecture based on work by Mary Shaw and David Garlan (Shaw and Garlan 1996). Their definition is:
“Software architecture encompasses the set of significant decisions concerning the organization of a software system like the collection of the structural elements and their interfaces where the system is made up; behavior as specified in collaboration the type of elements; composition of the structural and behavioral elements into larger subsystems; and an architectural style that guides this organization. Software architecture also involves functionality, usability, resilience, performance, reuse, comprehensibility, economic and technology constraints, tradeoffs and aesthetic concerns.”
In presupuesto pintura valencia of Enterprise Application Architecture, Martin Fowler outlines some typically common recurring themes when explaining architecture. He identifies these themes as:
“The highest-level breakdown of something into its parts; the decisions that are Hard to change; there are multiple architectures in a system; what is architecturally Significant can change over a system’s lifetime; and, ultimately, architecture boils Down to whatever the important stuff is.”
Software application architecture is the process of defining and creating a solution that’s well structured and meets all the technical and operational requirements. The architecture will be able to take into account and improve upon the normal quality attributes such as performance, security, and manageability.
The main focus of the Software architecture is the way the major elements and components in a application are employed by, or interact with, other major elements and components within the application. Selecting data structures and algorithms or the implementation details of individual components are design concerns, they’re no architectural concerns but sometimes Design and Architecture concerns overlap.
Before starting the architecting of any software, there are a few basic questions that people should make an effort to get answers for. They are as follows:
How the users of the machine will be interacting with the machine?
How will the application be deployed into production and managed?
Do you know the various non-functional requirements for the application form, such as for example security, performance, concurrency, internationalization, and configuration?
How can the application form be designed to be flexible and maintainable over time?
Do you know the architectural trends that might impact your application now or after it’s been deployed?
Goals of Software Architecture
Building the bridge between business requirements and technical requirements is the main goal of any software architecture. The purpose of architecture is to identify the requirements that affect the basic structure of the application form. Good architecture reduces the business risks associated with building a technical solution while an excellent design is flexible enough in order to handle the changes that may occur as time passes in hardware and software technology, as well as in user scenarios and requirements. An architect must think about the overall effect of design decisions, the inherent tradeoffs between quality attributes (such as for example performance and security), and the tradeoffs necessary to address user, system, and business requirements.
Principles of Software Architecture
The essential assumption of any architecture should be the belief that the design will evolve over time and that certain cannot know everything one need to know up front. The look will generally need to evolve through the implementation stages of the application form as one learn more, and as one tests the design against real world requirements.
Keeping the above statement in mind, let’s make an effort to list down some of the Architectural principles:
The system should be built to change rather than building to last.
Model the architecture to analyze and reduce risk.
Use models and visualizations as a communication and collaboration tool.
The key engineering decisions should be identified and applied upfront.
Architects should consider utilizing an incremental and iterative method of refining their architecture. Focus on baseline architecture to achieve the big picture right, and evolve candidate architectures as one iteratively test and improve one’s architecture. Do not try to get it fine the first time-design just as much as you can so that you can start testing the design against requirements and assumptions. Iteratively add details to the look over multiple passes to be sure that you obtain the big decisions right first, and then focus on the details. A standard pitfall is to dive into the details too quickly and obtain the big decisions wrong by making incorrect assumptions, or by failing woefully to evaluate your architecture effectively.
When testing your architecture, think about the following questions:
What were the main assumptions that were made while architecting the machine?
Do you know the requirements both explicit and implicit this architecture is satisfying?
Do you know the key risks with this architectural approach?
What countermeasures are in spot to mitigate key risks?
In what ways is this architecture an improvement over the baseline or the last candidate architecture?
Design Principles
When getting started with Software design, one should remember the proven principles and the principles that adheres to minimizes costs and maintenance requirements, and promotes usability and extensibility. The key principles of any Software Design are:
Separation of concerns: The key factor to be kept in mind is minimization of interaction points between independent feature sets to achieve high cohesion and low coupling.
Single Responsibility principle: Each component or module ought to be independent in itself and in charge of just a specific feature or functionality.
Principle of Least Knowledge: A component or object should not know about internal information on other components or objects.
Don’t repeat yourself (DRY): The intent or implementation of any feature or functionality ought to be done of them costing only one place. It should never be repeated in a few other component or module
Minimize upfront design: This principle can be sometimes known as YAGNI (“You ain’t gonna require it”). Design only what is necessary. Specifically for agile development, one can avoid big design upfront (BDUF). If the application requirements are unclear, or when there is a possibility of the look evolving over time, one should avoid creating a large design effort prematurely.
Design Practices
Keep design patterns consistent within each layer.
Do not duplicate functionality in a application.
Prefer composition to inheritance. When possible, use composition over inheritance when reusing functionality because inheritance escalates the dependency between parent and child classes, thereby limiting the reuse of child classes. This also reduces the inheritance hierarchies, which can become very difficult to cope with.
Establish a coding style and naming convention for development.
Maintain system quality using automated QA techniques during development. Use unit testing along with other automated Quality Analysis techniques, such as for example dependency analysis and static code analysis, during development
Not only development, also consider the operation of your application. Determine what metrics and operational data are needed by the IT infrastructure to ensure the efficient deployment and operation of your application.
Application Layers: While architecting and designing the system, one needs to carefully consider the various layers into that your application will be divided. There are several key considerations that need to be considered while doing that:
Separate the areas of concern. Break your application into distinct features that overlap in functionality as little as possible. The main benefit of this approach is a feature or functionality can be optimized independently of other features or functionality
Be explicit about how exactly layers communicate with one another.
Abstraction should be used to implement loose coupling between layers.
Do not mix different types of components in the same logical layer. For instance, the UI layer shouldn’t contain business processing components, but instead should contain components used to take care of user input and process user requests.
Keep the data format consistent within a layer or component.