Architectural Characteristics: Operational, Structural, Cloud-Native & Cross-Cutting

1. Operational Architectural Characteristics

Operational characteristics focus on system capabilities and operational needs at runtime.

Availability : The degree to which a system is operational and accessible when required. If 7×24 operation is required, rapid recovery mechanisms must be established.

Continuity : Disaster recovery capability, linked to business continuity requirements.

Performance : Response speed when executing functions. Not a single metric; must be broken down into measurable sub-metrics such as average response time, peak response time, and first-screen render time.

Recoverability : Speed of restoring the system after a disaster, including backup strategies and hardware redundancy requirements.

Reliability/Safety : The extent to which a system operates correctly under specified conditions for a specified period. Covers maturity, availability, fault tolerance, and recoverability; a key consideration is whether failure would cause massive loss.

Robustness : Ability to handle errors and boundary conditions, such as network outages or power loss.

Scalability : Ability to maintain performance as users or requests grow. Concerns long-term growth—monolithic architectures have scaling limits, while distributed styles can break bottlenecks.

Elasticity : Flexible scaling to handle traffic spikes. Concerns short-term bursts—related to scalability but distinct.

2. Structural Architectural Characteristics

Structural characteristics affect internal software structure, including component coupling and code organization.

Configurability : Ability to configure system behavior without code changes, reducing hard-coding and increasing flexibility.

Extensibility : Ease with which developers can extend system functionality. Encompasses architecture structure, engineering practices, internal design, and governance rules; microkernel architectures provide high extensibility via plugin mechanisms.

Installability : Ease of installing the system in different environments, affecting delivery efficiency.

Leverageability/Reuse : The extent to which common-domain components can be reused across multiple products.

Localization : Support for multiple languages on data entry and query screens.

Maintainability : Ease of enhancing and fixing the system by architects and developers, focusing on long-term codebase health.

Portability : Ability to migrate the system across platforms. Sub-characteristics include adaptability and replaceability.

Upgradability : Ease of upgrading to new versions, impacting long-term evolution capability.

3. Cloud-Native Architectural Characteristics

Cloud-native architectures introduce the following specific characteristics:

On-demand Scalability : Cloud platform's ability to dynamically add resources based on demand.

On-demand Elasticity : Cloud platform's ability to flexibly scale when resource demand spikes.

Zone-based Availability : Cloud platform isolates resources by compute zones to improve system resilience; related to availability and fault tolerance.

Region-based Privacy and Security : Legal ability to store data in different countries/regions; many nations have data residency regulations.

4. Cross-Cutting Architectural Characteristics

Cross-cutting characteristics span operational and structural dimensions, usually requiring global consideration.

Accessibility : System usability for all users, including those with disabilities.

Archivability : Data archiving needs and policies—whether to archive, and for how long.

Authentication : Strictness of user identity verification, including single sign-on and multi-factor authentication.

Authorization : Permission levels for user operations; role-based permission model design.

Legal : Legal constraints the system must obey, such as data residency restrictions (e.g., GDPR) and compliance requirements.

Privacy : Privacy protection requirements for personal data processing, involving transaction and internal personnel visibility.

Security : Encryption rules and constraints for data at rest and network communication between internal systems; authentication for remote user access and other security measures.

Supportability : Required level of technical support for the application, including logging, monitoring, and debugging facilities.

Usability/Achievability : Training required for users to achieve goals; user learning cost.

5. Conclusion

There is no standard checklist for architectural characteristics, but classification helps build a cognitive framework. In practice, select applicable characteristic combinations based on business needs and technical environment—not aiming for completeness, but capturing the key elements that truly influence architectural decisions.

The next article will explore how to identify architectural characteristics. 1. Head First Software Architecture, Chapter 2<br/> 2. Fundamentals of Software Architecture, 2nd Edition, Chapter 4