The Standard uses another term, architecture description , to refer to artifacts used to express and document architectures. The architecture of a system is cognizant of the system in its environment ; the environment determines the totality of influences on the system. One often-cited difference between architecture and design is this: architecture is outwardly focused on the system in its environment; whereas design is inwardly focused once the system boundaries are set.
It is interesting that different architecture communities place varying emphases on these. Software architecture has often been focused on software components as elements and their interconnections as a key relationship. System architecture emphasizes sub-system structures and relationships such as allocation.
Enterprise architecture emphasizes principles. The definition recognizes that all of these may play a part in architecture. While for man-made systems the architecture often reflects an intentional stance, this intention is not part of the definition. Although the Standard focuses on the artifacts used to describe architectures in the 2nd sense above, it recognizes that architecture description is one set of practices within the larger art or practice of architecture, sometimes called architecting , and that there is a unity to the notion of architecture from its roots in the built environment, through civil and more recent fields.
As Zachman reminds us, Architecture is architecture is architecture. The central question is whether the code is the specification or the specification is something abstract. The latter argument holds that the code is only one view of the spec. An architecture document is another. Sometimes, a simple sketch on the whiteboard is all you need in the right context.
In other contexts, a software architecture document will go a long way in communicating to others even your future self! For one thing, they might be producing software for other companies. Those who run that software will need something to go by. They will, however, be able to read the docs.
Some do at least as much implementation work as developers. But on the other end of the spectrum lie architects who deliver designs and have little to do with implementation. A software architecture document is a high-level map.
So, make your team more aware. Lightly document your software. Phil Vuollet uses software to automate process to improve efficiency and repeatability. He writes about topics relevant to technology and business, occasionally gives talks on the same topics, and is a family man who enjoys playing soccer and board games with his children. Measure quality with metrics, generate diagrams and enforce decisions with code rules, right in Visual Studio. Download the NDepend Trial and understand your.
NET code base technical-debt within a few minutes. NDepend Improve your. NET code quality with NDepend. Want to see living documentation of your software architecture, in vivid detail? Non-functional requirements help in that case.
Non-functional requirements NFRs define the criteria that are used to evaluate the whole system, but not for specific behavior, and are also called quality attributes and described in detail in architectural specifications. A situation in which the system has the desired combination of quality attributes, for example, of usability and performance or reliability, shows the success of the architecture and the quality of the software. When designing to meet any requirements, it is important to consider the impact on other attributes and find compromises between requirements.
Along with this, the value or priority of each individual attribute differs from system to system. This article covers not all existing attributes, but those covered can be a good start for designing your system.
To consider the types of quality attributes, we can use a diagram from ISO :. This standard describes the quality attributes for a software product. Performance shows the response of the system to performing certain actions for a certain period of time. In practice, the possible performance indicators include, for example:. Here you can find interesting latency numbers which every developer should know. Performance is almost always included in the list of key quality attributes that need to be considered by the architect, since it affects the entire system and can affect many parts of the architectural solution.
Therefore, on the internet, you can find a large number of examples of how to deal with performance problems. Interoperability is an attribute of the system or part of the system that is responsible for its operation and the transmission of data and its exchange with other external systems. A well-designed system facilitates integration with third-party systems.
To improve the interoperability, you can use well-designed external interfaces, standardization systems, etc. Interoperability cannot be ignored. In the best case, you will have to create additional layers for the interaction API.
At worst, it will be necessary to rebuild the entire system. Usability is one of the most important attributes, because, unlike in cases with other attributes, users can see directly how well this attribute of the system is worked out.
One of the key problems of usability is too much interaction or too many actions necessary to accomplish a task. Incorrect sequences of steps in multistage interfaces are also a problem of usability.