RBD (Reliability Block Diagram) is a standard method for assessing the reliability and availability of complex systems.
BQR’s CARE RBD software module is the ultimate tool for reliability allocation (top-down) and calculation (bottom-up), serving Reliability and System Engineers throughout product design cycle.
Benefits
How It Works

Steps for conducting a RBD analysis
Import
- Import the block tree and components from BQR’s FMECA or fiXtress using BQR’s Core Database
User Input
- Define Mission Time
- Add composite blocks of various types: Serial, Parallel, K out of N, Standby, and assign repair policy to each block
- Assign failure distributions and MTTR to leaves (blocks in the block tree that have no children)
- Add network diagrams and Markov chain models if necessary
Analysis
- The software validates the user data. If data is missing, user is notified
- The software analyzes the RBD and calculates Reliability, Availability, MTBCF, MTTCF, and MTTR for all blocks on all levels
- RBD Network analysis
- Embedded Markov chain models
- Monte Carlo simulations
Reports
- Tree report with all input and calculated data
- All reports can be saved as Excel, HTML or Word files
Advanced Modules
Features
- Reliability allocation (top-down) and calculation (bottom-up)
- Import block tree and failure rates from BQR MTBF, FMECA software or Excel
- RBD Network and embedded Markov chain models
- Analytic calculation of Mean Time Between Failures (MTBF), Mean Time To Repair / Replace (MTTR), Mean Time To first Failure (MTTF), Reliability, Availability, and Failure Rate
- Monte Carlo Simulation