SLO/SLA Calc

Know the Device. Build the System. Evaluate the Mission. Model availability and mission reliability offline. One purchase. No ads or subscriptions.

SLO/SLA Calc helps engineers, architects, SREs, and operators move from Device assumptions to resilient System decisions before deployment.

Model operational availability and time-bound Mission Reliability. Calculate Series, Parallel, N:M, and Cross-Connected topologies. Estimate Device Availability from manufacturer MTBF or documented generic estimates, then account for repair time, spare logistics, support agreements, EOL sourcing, and redundant power. Review exactly how each assumption affects the result.

Save Devices and subsystems as reusable Blocks, then arrange them into larger Systems. With Live Modeling, apply temporary failures to Blocks, internal Components, and switches. Remaining Availability updates immediately while animated Red and Blue paths show which inputs survive. Shared paths become Purple, and optional output switches select a healthy single handoff.

MODEL AVAILABILITY

• Calculate System and Device Availability
• Review a transparent Device calculation breakdown
• Edit the defaults used for new Device calculations
• Translate availability into downtime per day, week, month, or year
• Model Series, Parallel, heterogeneous N:M, and Cross-Connected designs
• Reuse saved Devices as named topology Components

EVALUATE A MISSION

• Estimate Mission Reliability for a defined duration in hours, days, or weeks
• Use stored MTBF or an explicit availability-only assumption
• Compare Mission Success, Interruption Risk, and any-Component failure probability
• See expected failed Components and the weakest individual contributor
• Distinguish provided, estimated, assumption-based, and mixed data

BUILD AND TEST SYSTEMS

• Assemble Systems from reusable Blocks and ordered Stages
• Use Direct or Full Cross multi-path Handoffs
• Add optional output switches and explicit Ideal Paths
• Simulate Block, Component, and switch failures
• Trace surviving flows in portrait or full-screen landscape

COMPARE AND SHARE

• Compare complete Systems and quantify downtime reduction
• Evaluate a design against a target SLO
• See remaining or exceeded error budget
• Generate and share professional PDF reports
• Export, share, preview, and import editable JSON-based .slosla files
• Edit imported Block Components and recalculate the design

Learn through an expanded Guided Tour, worked examples, formulas, model assumptions, and practical design guidance.

SLO/SLA Calc works entirely offline and stores Device defaults, Blocks, and Systems locally on your device. No account is required. Files leave your device only when you choose to export or share them.

One purchase unlocks the complete app. No ads, analytics, tracking, subscriptions, or in-app purchases.