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.
1.4
August 10, 2026
Version 1.4 turns saved Systems into interactive resilience models you can test, inspect, and share. LIVE MODELING - Apply temporary failures without changing the saved System. - Fail an entire Block, an internal Component, or a modeled output switch. - See Remaining Availability and service status recalculate immediately. - Restore individual elements or reset the complete simulation. VISIBLE INPUT FLOWS - Follow animated Red and Blue dashed paths through the surviving topology. - See shared connections become Purple when both inputs use the same route. - Distinguish enabled, delivered, and interrupted inputs. - Observe a single-output switch select one healthy handoff. FULL-SCREEN SIMULATION - Expand Live Modeling into a dedicated interactive canvas. - Rotate iPhone or iPad for a wider landscape view of longer Systems. - Keep topology, flow behavior, availability, and failure state visible together. EDITABLE SYSTEM SHARING - Export and share complete Systems as portable .slosla files. - Use the documented JSON-based data model to preserve Blocks, Components, stages, handoffs, switches, and calculated values. - Send designs through Files, AirDrop, Mail, Messages, or other compatible apps. - Preview, validate, recalculate, and safely import a shared System without overwriting local work. - Edit imported Block Components and update their availability values. - Continue modeling, comparing, reporting, and simulating the imported design. MORE MODELING CONTROL - Add an explicit 100% Ideal Path to represent an intentional passive bypass. Ideal Paths are non-failable during simulation. - Use topology-aware failure behavior for Series, Parallel, N:M, and Cross-Connected Blocks. - Compare extremely close designs with additional precision when fixed decimal places would hide the difference. - Share either a professional PDF report or the complete editable System model. LEARNING AND POLISH - Expanded Guided Tour covering Live Modeling and editable System sharing. - Updated How to Use and Reference material for the new workflow and terminology. - Refined failure labels, flow legends, output-switch behavior, and full-screen layouts. - Refreshed app icon. SLO/SLA Calc still works entirely offline. Simulations never modify a saved System, and files leave your device only when you choose to export or share them.
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.