Why I Built ReliabilityCalc
I'm Ajesh BS — a mechanical engineer working in maintenance at a precision forging plant. I built ReliabilityCalc because I was tired of doing MTBF and MTTR calculations on spreadsheets every single day.
The Story Behind This Project
As a Maintenance Engineer at Bansal Precision Forge Pvt Ltd, my daily work involves implementing preventive and predictive maintenance strategies for forging equipment. That means I calculate MTBF, MTTR, and availability numbers regularly — tracking KPIs, building maintenance plans, and keeping IATF documentation in order.
Early on, I realized I was spending too much time plugging numbers into Excel templates and double-checking formulas when I could have been analyzing trends and actually improving equipment uptime. I looked for a simple, free online calculator — and couldn't find one that was both accurate and easy to use.
So I built one. What started as a basic MTTR calculator for my own use grew into ReliabilityCalc — a full platform with 4 reliability calculators (MTBF, MTTR, Availability, OEE) and 7 quality management tools (Pareto charts, fishbone diagrams, control charts, histograms, check sheets, scatter diagrams, and flowcharts).
Every formula and calculation method on this site comes from real engineering practice — the same methods I use on the shop floor. The tool is free because I believe every engineer, student, and quality professional should have access to proper reliability tools without paying for expensive software licenses.
Education & Background
B.E. Mechanical Engineering
Mar Ephraem College of Engineering and Technology
Tamil Nadu, India · 2016–2020
Engineer Trainee — Maintenance
Bansal Precision Forge Pvt Ltd
Preventive & predictive maintenance · IATF documentation · KPI analysis
CAD & Simulation Training
ANSYS Workbench (40hrs) · CATIA (45hrs) · Siemens NX (Coursera)
Certifications
What Makes ReliabilityCalc Different
This isn't a generic calculator app. Every feature was built to solve a real problem I faced on the job.
Built from Practice
The formulas and methods here are the same ones I use for daily maintenance KPI tracking. No textbook-only theory — this is how it works on real equipment.
Actually Free
No trial limits, no signup walls, no premium tiers. All 4 calculators and 7 quality tools are completely free. Your calculation data stays in your browser and is never sent to any server.
Quality-First
As a Six Sigma Black Belt, I built in proper validation, clear formula references, and industry-standard calculation methods. The results match what you'd get doing it by hand.
Who Is This For?
Maintenance Engineers
Quick MTBF/MTTR calculations without opening Excel. Track availability and OEE for your equipment. Export results for your reports.
Quality Professionals
Build Pareto charts, fishbone diagrams, and control charts right in your browser. Useful for IATF 16949 and ISO 9001 documentation.
Engineering Students
Learn reliability engineering concepts with real formulas and worked examples. Understand how these metrics are used in actual manufacturing.
Operations Managers
Get quick equipment performance numbers for management reviews. OEE and availability calculations in seconds, not hours.
Start Calculating
All tools are free, instant, and require no signup. Pick a calculator and get your results in seconds.