More specifically; if you tell someone to present you the 'design' - what would you expect them to present? Same goes for 'architecture'. Correct me if I'm wrong. You're right yes.
The architecture of a system is its 'skeleton'. It's the highest level of abstraction of a system. What kind of data storage is present, how do modules interact with each other, what recovery systems are in place. Just like design patterns, there are architectural patterns: MVC, 3-tier layered design, etc. What are the responsibilities, functions, of module x?
Of class Y? What can it do, and what not? What design patterns can be used? They are at the same time: different 1 stages , 2 areas of responsibility , and 3 levels of decision-making.
Even if the stages or areas of responsibility blend together and happen all over the place, it is always good to know what level of decision-making is happening. We could go on forever with this.
I'm trying to keep it a summary. If no one decides to do architecture, then a default one happens that is probably poor.
Ditto for design. These concepts are almost more important if there are no formal stages representing them. Architecture comprises the frameworks, tools, programming paradigms, component-based software engineering standards, high-level principles.. While design is an activity concerned with local constraints, such as design patterns, programming idioms, and refactorings.
What is a software architecture?
I found this as I was looking for simple distinction between architecture and design myself; What do you think of this way of looking at them:. Architecture means the conceptual structure and logical organization of a computer or computer-based system. Design means a plan or drawing produced to show the look and function or workings of a system or an object before it is made. What part is the Design, the How is the concrete implementation and the intersection of What and How is Architecture.
There are also design decisions, that are not architecturally significant, i. The link that gives good analogy. Architecture is the allocation of system requirements to system elements. Four statements about an architecture:.
Architecture is an essential engineering step when a complexity of the system is subdivided. Example: Think about your house, you don't need an architect for your kitchen only one element involved but the complete building needs some interaction definitions, like doors, and a roof. Design is a informative representation of the proposed implementation of the function.
It is intended to elicit feedback and to discuss with stakeholders. It might be good practice but is not an essential engineering step. It would be nice to see the kitchen design see before the kitchen is installed but it is not essential for the cooking requirement :.
I think we should use the following rule to determine when we talk about Design vs Architecture: If the elements of a software picture you created can be mapped one to one to a programming language syntactical construction, then is Design, if not is Architecture.
So, for example, if you are seeing a class diagram or a sequence diagram, you are able to map a class and their relationships to an Object Oriented Programming language using the Class syntactical construction. This is clearly Design. In addition, this might bring to the table that this discussion has a relation with the programming language you will use to implement a software system.
Introduction to Software Architecture
If you come up with a diagram that shows packages and its dependencies, that is Design too. You can map the element a package in this case to a Java syntactical construction.
Software architecture definition pdf file
Now, suppose your Java application is divided in modules, and each module is a set of packages represented as a jar file deployment unit , and you are presented with a diagram containing modules and its dependencies, then, that is Architecture. You might also notice that this diagram represents a step higher in the level of abstraction of your software model. Any diagram above coarse grained than a package diagram, represents an Architectural view when developing in the Java programming language.
On the other hand, if you are developing in Modula-2, then, a module diagram represents a Design. I agree with many of the explanations; essentially we are recognizing the distinction between the architectural design and the detailed design of the software systems.
While the goal of the designer is to be as precise and concrete in the specifications as it will be necessary for the development; the architect essentially aims at specifying the structure and global behavior of the system just as much as required for the detailed design to begin with.
A good architect will prevent hyper-specifications - the architecture must not be overly specified but just enough, the architectural decisions established only for the aspects that present costliest risks to handle, and effectively provide a framework "commonality" within which the detailed design can be worked upon i.
Indeed, the architecture process or life-cycle just follows this theme - adequate level of abstraction to outline the structure for the architecturally significant business requirements, and leave more details to the design phase for more concrete deliverables. Architecture is design, but not all design is architectural. Therefore, strictly speaking, it would make more sense to try to differentiate between architectural design and non-architectural design.
And what is the difference? It depends! Each software architect may have a different answer ymmv! We develop our heuristics to come up with an answer, such as 'class diagrams are architecture and sequence diagrams are design'.
See DSA book for more. It's common to say that architecture is at a higher abstraction level than design, or architecture is logical and design is physical.
But this notion, albeit commonly accepted, is in practice useless. Where do you draw the line between high or low abstraction, between logical and physical? Having said all that That is, when should I stop describing the design in diagrams or prose and should move on to coding?
Yep that sounds right to me. The design is what you're going to do, and architecture is the way in which the bits and pieces of the design will be joined together. The software architecture of a program or computing system is the structure or structures of the system, which comprise software components, the externally visible properties of those components, and the relationships between them.
Software design is a process of problem-solving and planning for a software solution.
After the purpose and specifications of software are determined, software developers will design or employ designers to develop a plan for a solution.
It includes low-level component and algorithm implementation issues as well as the architectural view. I view architecture as Patrick Karcher does - the big picture. For example, you can provide the architecture to a building, view its structural support, the windows, entries and exits, water drainage, etc. But you have not "designed" the floor layout's, cubicle positions etc. So while you've architected the building you have not designed the layout of each office.
I think the same holds true for software. Good question Architecture is specifically not about…details of implementations e. Design is concerned with the modularization and detailed interfaces of the design elements, their algorithms and procedures, and the data types needed to support the architecture and to satisfy the requirements.
Defining the Terms Architecture, Design, and Implementation. Architecture: Structural design work at higher levels of abstraction which realize technically significant requirements into the system.
The architecture lays down foundation for further design. Design: The art of filling in what the architecture does not through an iterative process at each layer of abstraction. Statements on the nature of the software that are non-local and intensional are architectural.
Statements that are local and intensional are design.
Architecture is about relationship, which requires the many. Architecture has components. Design is about content, which requires the one. Design has properties, qualities, characteristics.
We typically think that design is within architecture. Dualistic thinking gives the many as primordial. But architecture is also within design. It's all how we choose to view what is before us - the one or the many.
Architecture The overall design of the system including interactions with other systems, hardware requirement, overall component design, and data flow. Design The organization and flow of a component in the overall system. This would also include the component's API for interaction with other components.
Software architecture is best used at the system level, when you need to project business and functions identify by higher architecture levels into applications. For instance, your business is about "Profit and Loss" for traders, and your main functions involved "portfolio evaluation" and "risk computation".
But when a Software Architect will details his solution, he will realize that:. It needs to be refined in manageable projects like:. It will produce the specifications needed for the last Architecture layer the "Technical Architecture" to work on in term of technical framework or transversal components , and for the project teams more oriented on the implementation of the business functions to begin their respective projects.