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RBD - Reliability Block Diagram Software from BQR |
RBD - System reliability analysis for sophisticated and large scale systems
| Improving System's Reliability and Up-Time |
Reliability Block Diagram is a technique and a graphical representation that is used to model and analyze the reliability and availability of large and complex systems, which includes redundancies in non-serial architecture or the blocks with multiple states. The RBD enables analysis of real world scenarios with combination of redundant or various system states.
The RBD Module uses bottom-to-top calculation or top–down requirements allocation providing standard system and sub-system parameters such as reliability, availability, down time, failure rates, and more. BQR's RBD provides a simple way to compare various reliability configurations in an attempt to find the best inclusive system design.
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Key Features
- Assesses the level of failure tolerance achieved
- Performs trade-off scenarios to optimize the reliability and cost within a system
- Quantifies the reliability of a system or subsystem
- Identifies intersystem disconnects as well as areas of incomplete design definition (network model)
- Identifies possible system design matrix
- Provides the real Critical MTBF of a redundant system
- Can combine various Reliability models (basic, Markov and Network) in one project
- Provides results for all reliability parameters in needed to evaluate a system
- Helps to design the correct redundancy to achieve certain availability
| Under the Hood of BQR's RBD |
BQR's RBD calculation program does not use a Monte-Carlo method of statistical simulation. It contains analytical formulas and numerical algorithms providing quick calculations with control for higher accuracy.
The tool’s core engine is based on a Hierarchical Graphical Reliability Architecture Builder and a mathematical solver for the development of Complex Redundant & Maintenance Concepts while minimizing Life-Cycle-Cost. The RBD provides sensitivity analysis utility for the development and guidelines of System designers and managers.
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| Tool for Complex Systems |
The RBD Package is an advanced tool for the analyzing and modeling complex hi-tech systems and sub-systems, such as: telecommunications, semiconductors, satellites, broadband, wired & wire-less, storage, safety systems and others. BQR's RBD provides a full flexibility tool tailored to specific applications. BQR's RBD data may be used in all BQR's Software packages to provide shared data and advanced analysis covering all aspects of Reliability, Availability and Maintainability.
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| The RBD Platform |
The user interface of the RBD provides advanced graphical representation of system hierarchy and easy navigation features. It covers comprehensive and customized reporting capabilities, graphs and users wizard. The user can easily navigate between sub-systems or view and edit any sub-systems. The RBD provides import/export mechanism to other BQR's packages and for a variety of other analysis performed by other CARE software packages.
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| Technical description of the BQR's RBD |
- Supported models: Serial, Parallel, K-out of N (with identical and different sub blocks), Standby, Markov, Network, and any of their combinations in hierarchic tree.
- Types of failure time distributions for lowest components: Exponential, Normal (truncated at 0), Lognormal, Uniform, Pareto, Rayleigh, Weibull, Bathtube.
- For composite blocks (having sub blocks) the failure time distributions are calculated (non-parametric, as Reliability (Density, Hazard rate) – time arrays)
- Available Repair types of a block:
- Replacement of entire block (together with all sub blocks),
- Disassembly, with sub blocks repair or replacement
- No repair
- Available Repair types of sub blocks:
- Cold repair (after the parent block failure and stopping),
- Hot repair (during the parent block operation, if the other redundant sub blocks operate)
- No repair
- Available reliability parameters for each block: Mission Reliability, Availability, Mean Time Between Critical Failures (MTBCF), Mean Time To Failure (MTTR), Average Failure Rate Per Million Hours (FPMH), Down Time during mission due to failures and corrective maintenance.
- Available safety parameters (for the blocks of Safety Related System according to IEC-61508): Safe Failure Ratio, Diagnostic Coverage, Diagnostic Test Interval, Proof Test interval, Safe Failure Fraction, Mean Time Between Dangerous Failures (MTBDF), Safety Function Demand Type, Probability of Failure on Demand (PFD), Probability of Failure per Hour (PFH), Safety Integrity Level (SIL), Failure Damage, Unsafe Failure Probability, Damage Risk
- Available calculation types:
- Reliability and safety parameters calculation bottom-to-top basing on lowest blocks distributions, reliability and maintainability models of all blocks;
- Reliability requirements allocation top-down based on Availability, Reliability and MTBCF requirements for system level and lowest blocks failure rate relation (complexity factors)
- Available import-export capabilities:
- Importing a project from BQR Core Data Base (CDB) and exporting to CDB
- Copy – Paste a project or sub project to another project
- Creating a project from a template
- Help capabilities:
- Sensitive wizard
- Systematic Help menu
- ON-line Help
- Tutorial from Help menu
- Guide
- Status bar and tool tip help
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Key Features
- Calculates bottom to top: Reliability, Availability, Down-Time, MTBCF, MTTR and Failure Rates for the top level and for each assembly in the hierarchy structure
- Top-Down Allocation Algorithm for RAMS requirements - Multi Model
- Basic models are: Serial, Parallel, K-out-of-N and Stand-By with or without repair
- Advanced models are: Network and Markov
- Maintenance policy: Replacement, Disassembly, Hot, Cold & No-Repair
- Calculated Reliability, Density and Failure Rates curves versus time for each block
- Failures and repairs mechanism
- Allows choosing distribution for basic blocks: Exponential, Log-normal, Weibull, Uniform, Pareto, Rayleigh and Bath-tube
- Advanced mathematical algorithms for composite blocks failure time distribution and mean parameters
- Quick and accurate results using analytical & numerical calculations (without slow Monte-Carlo simulation)
- Presents calculation results graphically
- Visual diagramming
- Handles the functional block trees (no limit of blocks and levels)
- Shares data with other CARE®/CAME modules via CORE database
- Builds RBD models automatically from BQR's MTBF, FMECA & FTA
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Technical Specification
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 Configuration Types
- Markov
- Networks
- Series
- Simple
- Parallel
- K out of N identical
- K out of N Different
- Cold/Hot standby
- Redundant
- Bridge
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Component Repair Policies
- Upon system failure
- Immediately after component failure
Analysis Outputs
- Graphical diagram
- Reliability/unreliability vs. time
- Availability/unavailability
- Hazard rate vs. time
- Total downtime during mission
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Repair types
- Replacement
- Disassembly
- No Repair
- Hot
- Cold
Supported Calculations
- Failure Rate
- Failure Density
- MTBF
- MTBCF
- MTTCF
- FPMH
- MTTR
- Availability
- Reliability vs. Time
- Mode Transition Rate
- Downtime
- Steady-state availability
- Cost Analysis
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Data Linkages
- FMEA
- MTBF Prediction
- MTTR
- CAME Package
- FTA
Report Formats
- HTML
- Microsoft Word
- Microsoft Excel
- XML
- RTF
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Distributions Supported
- Exponential
- Normal
- Weibull
- Lognormal
- Uniform
- Pareto
- Bathtub
- Rayleigh
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Databases Supported
- Microsoft SQL Server
- Microsoft Access
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The CARE-RBD Package is provided in three modules |
The RBD- Basic includes the following calculation types: Simple, Serial - The block fails when a sub block fails, Parallel - The block fails when all sub blocks fail. All sub blocks operate simultaneously until failure, K out of N - The block fails, when any K sub blocks fail from N, Stand By - The block fails when all sub blocks fail. Only one sub block operates each moment. The rest are spares or in failure.
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The RBD-Markov is an extension to the Basic version. The Markov extension allows to simulate almost any possible complex states of a system, including the transition drivers, repair times, different states of the sub-blocks, and more.
RDB- Markov model uses states and transitions (State Transition Diagram) of corresponding sub blocks. The entire Markov block fails only if a predefined failure state, in the State Transition Diagram, is reached as a result of random failures in the sub-blocks.
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The RBD-Network is an extension to the RBD-Basic version. The Network extension allows users to simulate complex networks, including multipoints entries and exits to and from the system
RBD – Networks fails only if there are no valid (operational) paths from the Input to the Output. Any network configuration may be build where every sub-block (connection) can be composed from any of the Basic and Markov models. If the network may be split to some sub networks with a few connections between them, each sub block can be replaced by "multipin" block, simplifying the common solution. Each sub-block can also be composed from any of the Basic and Markov models.
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