This tool helps engineers and operators model system availability and evaluate designs before deployment. It calculates availability for various configurations, estimates device reliability, and allows users to build and visualize complex systems. Generate professional PDF reports and review key definitions for availability and reliability.
1.3
August 1, 2026
Version 1.3 makes advanced availability modeling easier to build, understand, and explain. CROSS-CONNECTED TOPOLOGIES - Model two-layer and three-layer Cross-Connected Blocks. - Assign a different availability value to every component. - Connect compatible multi-path stages using Direct or Full Cross handoffs. - Add an optional output switch when multiple paths converge into one handoff. SYSTEM COMPARISON - Compare two saved Systems side by side. - See availability differences, calculated downtime reduction, and design complexity. - Optionally evaluate both Systems against the same target SLO. - Get a clear decision summary explaining which design provides greater modeled availability. IMPROVED GUIDANCE - Follow an expanded guided tour with a worked Parallel example. - Load the example directly into the calculator and explore the result. - Review consistent definitions for Components, Blocks, Layers, Paths, Stages, Handoffs, and Systems. - Learn about common availability design pitfalls involving infrastructure, shared failure domains, cloud regions, security, manual intervention, and recovery testing. REPORTING AND RELIABILITY - View Cross-Connected architecture and handoffs in System diagrams and PDF reports. - Improved editing and deletion behavior for complex System stages. - Additional usability and stability improvements throughout the app.
MoreSLO/SLA Calc is used by engineers and operators to model system availability and evaluate designs before deployment. It helps calculate availability for various configurations and estimate device reliability.
It calculates availability for series, parallel, and N:M designs. It can also estimate device availability using metrics like MTBF, MTTR, spare availability, and EOL status.
Yes, you can save devices and subsystems as reusable Blocks. These Blocks can then be combined into larger Systems, allowing for efficient modeling of complex architectures.
Yes, SLO/SLA Calc works offline. Saved Blocks and Systems are stored locally on your device, and no account is required to use the app.
SLO/SLA Calc can generate and share professional PDF system reports. These reports help visualize the resulting architecture and compare performance against a target SLO.
SLO/SLA Calc is a paid application priced at $1.99.
The latest version, 1.2, was released on July 19, 2026, indicating recent development activity. The app was initially released on July 16, 2026.
No, SLO/SLA Calc does not contain advertisements. It is a paid application that offers an ad-free experience.