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Goals

Begin your project with informed decisions

Data Storage
Data Access
Data Processing
User Interfacing

Make the building blocks modular

Easier to divide for a group
Easier to expand/reuse in the future

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Considerations

Stakeholders
Separation of concerns
Quality
Style
Conceptual Integrity

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Multitude of stakeholders: software systems have to cater to a variety of stakeholders such as business managers, owners, users and operators. These stakeholders all have their own concerns with respect to the system. Balancing these concerns and demonstrating how they are addressed is part of designing the system.^[2] This implies that architecture involves dealing with a broad variety of concerns and stakeholders, and has a multidisciplinary nature.

Separation of concerns: the established way for architects to reduce complexity is by separating the concerns that drive the design. Architecture documentation shows that all stakeholder concerns are addressed by modeling and describing the architecture from separate points of view associated with the various stakeholder concerns.^[11] These separate descriptions are called architectural views (see e.g. the 4+1 Architectural View Model).

Quality-driven: classic software design approaches (e.g. Jackson Structured Programming) were driven by required functionality and the flow of data through the system, but the current insight^[2] is that the architecture of a software system is more closely related to its quality attributes such as fault-tolerance, backward compatibility, extensibility, reliability, maintainability, availability, security, usability, and other such –ilities. Stakeholder concerns often translate into requirements on these quality attributes, which are variously called non-functional requirements, extra-functional requirements, system quality requirements or constraints.

Recurring styles: like building architecture, the software architecture discipline has developed standard ways to address recurring concerns. These “standard ways” are called by various names at various levels of abstraction. Common terms for recurring solutions are architectural style, strategy or tactic, reference architecture and architectural pattern.

Conceptual integrity: a term introduced by Fred Brooks in The Mythical Man-Month to denote the idea that the architecture of a software system represents an overall vision of what it should do and how it should do it. This vision should be separated from its implementation. The architect assumes the role of “keeper of the vision”, making sure that additions to the system are in line with the architecture, hence preserving conceptual integrity.

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Stakeholders

Who are your stakeholders?

Describe your project from each point of view.

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Design Patterns (Style)

Client Server
Data Centric
Event Driven
Monolithic
Peer-to-Peer

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Client Server - Client is making requests for resources which are distributed by a server application.

DataCentric - Reliant on a Database for Frequent access to dynamic data sets.

Event-driven architecture (EDA) is a software architecture pattern promoting the production, detection, consumption of, and reaction to events.

An event can be defined as "a significant change in state".^[1] For example, when a consumer purchases a car, the car's state changes from "for sale" to "sold"

Monolithic - In software engineering, a monolithic application describes a single-tiered software application in which the user interface and data access code are combined into a single program from a single platform.

Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or work loads between peers. Peers are equally privileged, equipotent participants in the application. They are said to form a peer-to-peer network of nodes

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Design Patterns

Which design pattern best suits your project?

Check out the book!

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Process

Architectural Analysis

Planning

Architectural Synthesis

Execution

Architectural Evaluation

Requirements Met?

Architectural Evolution

Adapt in the future

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Architectural Analysis is the process of understanding the environment in which a proposed system or systems will operate and determining the requirements for the system. The input or requirements to the analysis activity can come from any number of stakeholders and include items such as:

what the system will do when operational (the functional requirements)
how well the system will perform runtime non-functional requirements such as reliability, operability, performance efficiency, security, compatibility defined in ISO/IEC 25010:2011 standard ^[20]
development-time non-functional requirements such as maintainability and transferability defined in ISO 25010:2011 standard ^[20]
business requirements and environmental contexts of a system that may change over time, such as legal, social, financial, competitive, and technology concerns ^[21]

Architectural Synthesis or design is the process of creating an architecture. Given the requirements determined by the analysis, the current state of the design and the results of any evaluation activities, the design is created and improved. See^[2]^[19] for a discussion of various techniques for improving a current design.

Architecture Evaluation is the process of determining how well the current design or a portion of it satisfies the requirements derived during analysis. An evaluation can occur whenever an architect is considering a design decision, it can occur after some portion of the design has been completed, it can occur after the final design has been completed or it can occur after the system has been constructed. Some of the available software architecture evaluation techniques include Architecture tradeoff analysis method and TARA.^[22] Frameworks for comparing the techniques are discussed in frameworks such as SARA Report ^[23] and Architecture reviews: practice and experience.^[24]

Architecture Evolution is the process of maintaining and adapting an existing software architecture to meet requirement and environmental changes. As software architecture provides a fundamental structure of a software system, its evolution and maintenance would necessarily impact its fundamental structure. As such, architecture evolution is concerned with adding new functionality as well as maintaining existing functionality and system behaviour.

Architecture requires critical supporting activities. These supporting activities take place throughout the core software architecture process. They include knowledge management and communication, design reasoning and decision making, and documentation.

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Implications of the Hardware

PC
Mobile Platform
Supercomputer
Prototyping Device

Arduino
Raspberry Pi
FPGA

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Implications of the Operating System

Windows

OS X

Linux

Custom

None

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Implications of the Environment

Environment Variables
chroot
Account/Process Privileges

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Implications

What hardware and OS will your team be using?

Will your program interact with other programs? Files? The system environment?

How will these factors affect how you design your product?

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