Its reliability and safety modules cover all widely known reliability standards and failure analysis approaches. RAM Commander is indispensable tool for ensuring reliability of sophisticated systems.
RAM Commander is modular software allowing a customer the flexibility of gradual addition of the modules to the package in accordance with the requirements of a project or the budget constraints.
Advanced Specialty Engineering Networked Toolkit (Asent)
See also Advanced Specialty Engineering Networked Toolkit (Asent)
for a Powerful Client/Server alternative
Modules cover:
Reliability Prediction
RAM Commander provides everything necessary for primary reliability prediction based on one of the prediction models for electronic equipment, mechanical and electro-mechanical equipment. Graphical presentation of the projects Product Tree allows visibility and easy data manipulation.
Product Tree Table.
Performing reliability allocation, Pareto analysis, RAM sensitivity analysis producing temperature curves and mission profile are extremely easy with RAM Commander.
Pareto Report. Pareto analysis identifies components or component families that contribute most significantly to system or assembly failure rate – about 80% of total failure rate
Temperature Curve Report. Presents the failure rate or MTBF as a unction of temperature: regular, multi-environment & multi-items on one graph.
Field Failure Rate Module
Reliability Block Diagram (RBD)
RBD module allows performing the functional Reliability and Availability analysis of systems with variety of reliability distributions, and types of redundancy and repair factors. While the basic RAM Commander module provides the reliability calculations and predictions for non-redundant systems, RBD utilizes data defined in the basic module, and performs either analytical calculation or Monte Carlo simulation depending on the type of a reliability configuration of the system.
The analytical technique is used mostly for exponential distributions. For each RBD, a graph of the reliability function R(t) can be drawn and MTBCF (Mean Time Between Critical Failures) can be calculated using numeric integration.
Reliability Block Diagram
MTBCF graph
System Configuration feature of the RBD module is an ingenious answer to the requests of our customers who need to compare the reliability and availability of various system configurations created as the sub-sets of the project product tree. The creation of the unlimited number of system configurations, easy transformation of each configuration into an RBD, MTBCF calculation, synchronised with the product tree changes, and finally a clear and elegant graphical presentation – all this makes the System Configuration feature an invaluable addition to the RAM Commander performance.
System Configuration Table
Monte Carlo simulation with its’ high speed, accuracy, and large number of steps allows to evaluate Reliability and Availability for arbitrary configurations when there is no analytical solution, i.e. complex configurations, including standby, partially loaded and active redundancy; full or restricted repair with non-exponential distribution of time-to-repair; analysis under non-steady, transient state; dependent RBD elements; analysis of periodical inspection policy.
Maintainability
Maintainability Prediction and Analysis in RAM Commander is based on the MIL-HDBK-472, Procedure V, Method A. Maintainability module is used to predict maintainability of systems and equipment of any type, including avionics, ground and shipboard electronics, mechanical equipment, etc., at all levels of maintenance.
Maintainability procedure definition
Maintenance Engineering Analysis report
Spare Parts Analysis & Optimisation:
RAM Commander Spare Parts Analysis and Optimisation is based on two cost optimisation criteria: Total No Shortage Probability & Availability. The module performs Cost-Availability optimisation of repairable and discardable parts for all levels of repair. Spare Parts Analysis and Optimisation module takes into account the variety of mission applications, e.g., when the primary restriction is weight or volume, such as for fly-away kits or when no repair or supply of spare parts is permitted (unsupported mission). Data entry for the module is minimised due to the usage of the data used in the RAM project.
Spare Parts Optimization
RAM Commander’s Markov is a powerful tool with the following features:
- Up-to-date, intuitive and powerful Markov Chain diagram interface with possibilities of full control over the diagram: elements location, colours, styles, zooms etc.
- Convenient ways of diagram printing and simple Copy & Paste transfer to other applications
- Calculation of Steady-State Mode
- Calculation of Time-Dependency Mode
- Calculation of Availability, Unavailability, Failure and Repair rate and frequency, MTBF, MTTF, MTTR, Reliability/Unreliability and other system parameters
- Results output:
- System parameters for selected times as table or graph
- State probabilities for selected times as table or graph
- Steady-State results report
- Transition Matrix report
- States and Transitions data report
- Results export to Excel, Word, HTML formats.
Stress – Strength Analysis
Stress/Strength Analysis – Structural/Mechanical Analysis of Components and Systems Stress/Strength analysis method determines the probability of failure based on the probability of stress exceeding strength.
Calculation of Failure Probability (Unreliability) by:
- Distributions of Stress and Strength
- Variation information between Stress and Strength (Factor of Safety n and Variations)
Having distributions of Stress and Strength, we may calculate failure probability (Unreliability):
Having variation information between stress and strength (Factor of Safety n and Variations), we may also calculate the unreliability:
According to ATA, the ATA MSG-3 publication outlines a decision-logic process for determining initial scheduled maintenance requirements for new aircraft and/or power plants. This document presents a means for developing maintenance tasks and intervals acceptable to regulatory authorities, operators and manufacturers. The analysis has the objective to maintain an inherent safety level and to achieve an optimal balance between maintenance costs and reliability.
RAM Commander’s MSG-3 module main features:
- Intuitive step-by-step procedure
- Integration with Reliability and FMECA analysis modules
- Interactive decision diagrams
- Final report generation is MS Word
- Customisable MS Word report template
The MSG-3 module is integrated with RAM Commander Reliability and FMECA modules. It divides the procedure into 7 steps including system definition, maintenance significant items selection, failure effect categorisation, task selection and development and report generation.
It brings user through the decision-making process using interactive decision diagrams taken from the standard:
As an output of the procedure user gets final report generated in MS-Word with all the data inside. Report is generated based on customizable MS Word template; user may change the template design.
Derating
The Derating module is used to analyse the over-stress of components under current temperature conditions. The module provides a tool to define Derating curves and identify overstressed components, i.e., those working under stress exceeding the specified rating value. Rating, or maximum rated stress, is the specified value of temperature, power, voltage or current that define the absolute maximum stress limits. Exceeding these values creates a high probability of part damage/failure.
The maximum rating is specified in the part specifications or in standard for this type of part. It is a well known practice in many companies to define limit values of stress for various components as a function of temperature. These limits, “Derating curves”, are part of the company policy of component usage. A report created by the Derating module includes all components in the selected part of the system, or only the overstressed ones. Derating reports with indication of overstressed parts.
Libraries and Data Import
RAM Commander enables the user to access and use various sources of reliability information: extensive RAM Commander or user-defined component libraries, field data or data imported with the help of Import Wizard.
FMECA
Failure Mode, Effects and Criticality Analysis (FMECA) is a natural continuation, and in many cases inseparable part of the Reliability Analysis. Previously a separate software package, FMECA is now a fully-integrated RAM Commander module. FMECA module uses a product tree previously created by the user for the reliability analysis purposes.
The RAM Commander FMECA module is suitable for both hardware and functional approaches to FMECA, and fully complies with MIL-STD-1629 A, commercial standards, and Good Manufacturing Practice (GMP) requirements.
RAM Commander FMECA module makes the FMEA process easy and visible: the product tree and the corresponding to each item sequence of Failure Modes => Next Higher Effects => End Effects are totally visible in the same window.
Extensive use of the FMECA Libraries facilitates the process even more and contributes to the accuracy of the performed analyses and reports. You can perform both the FMEA and FMECA calculating failure mode ratios, conditional probabilities and item criticality numbers.
Testability Analysis
Testability Analysis sub-module of the FMECA module is intended for in-depth Testability analysis. The main characteristics of Testability – BIT/Detection Coverage and Fault Isolation Resolution – can be calculated for each maintenance level (Organisational, Intermediate, Depot) and for specific detection methods (BIT, BITE, external test equipment, etc.). Test method efficiency and indication are defined for each test method or a group of test methods.
Testability analysis is widely used for the development of necessary supporting documentation: maintenance manuals, troubleshooting procedures and inspection requirements.
The uniqueness of the RAM Commander approach to process/design FMEA is reflected in the graphical presentation of the process flow:
Main window of the RAM Commander Process & Design FMEA
Decompose the system or process into components or sub-processes. For each functional block, define name & function, enter failure mode causes and effects manually or from the libraries. Process & Design FMEA module provides full graphical and textual visibility of the Potential Failure Mode => Cause => Effects chain.
Edit cause dialog contains corrective actions and RPN (risk priority number
Process and Design FMEA produce all the reports required by PFMEA: design FMEA, Process FMEA, Pareto analysis, regular FMEA with all NHE, basic fault tree
Fault Tree Analysis (FTA)
RAM Commander’s FTA (Fault Tree Analysis) software module is the one of the unique features of the RAM Commander. It is simplified FTAnalyzer, fully integrated with RAM Commander product tree,reliability prediction and FMECA. It implements and summarises the first-hand experience gained by the FTA experts in hundreds of projects using RAM Commander and other software tools from our portfolio.
Main window of the RAM Commander Fault Tree Analysis Module
Fault Tree Analysis is one of the most widely used methods in system reliability and failure probability analysis. A fault tree is a graphical representation of a logical structure representing undesired events (“failures”) and their causes. You create the logical structure by using gates and represent undesired events by using basic events. Reliability parameters are assigned to the basic events. Widely used in system reliability studies, fault tree analysis offers the ability to focus on an event of importance, such as a highly critical safety issue, and work to minimize its occurrence or consequence. The probability of the top-level event can then be determined by using mathematical techniques. The resulting fault tree diagram is a graphical representation of the chain of events in your system or process, built using events and logical gate configurations.
FTA Basic Event data
Example of FTA Unavailability and MCS Analysis report
Example of FTA Importance and Sensitivity Analysis report
Two types of analysis can be conducted using Fault Trees:
- Qualitative Analysis: performed by means of Minimal Cut Sets (MCS) building
- Quantitative Analysis: calculating the Absolute probabilities, i.e. the probabilities of system failures
Fault Tree Analysis is acknowledged as a key tool for increasing safety. It is unique and indispensable in analysing risks and determining various combinations of hardware, software, and human error failures that result in a specified risk or system failure. Fault tree analysis is useful both in designing new products/services and in dealing with identified problems in existing products/services. In the quality planning process, the analysis can be used to optimise process features and goals and to design for critical factors and human error. As part of process improvement, it can be used to help identify root causes of trouble and to design remedies and countermeasures.
After Unavailability calculation and MCS analysis, Importance and Sensitivity Analysis may be performed. Importance analysis results help to select those fault tree events, which contribute most to the system’s unavailability. Sensitivity analysis helps to choose those events, where a relatively small change will lead to a relatively large system unavailability changes. Calculated values are Fussell-Vesely importance (FV Imp), Risk Decrease Factor (RDF), Fractional Contribution (FC), Risk Increase Factor (RIF) and Sensitivity Value for each Basic or Undeveloped Event.
FTA is used by other RAM Commander modules – the Safety Assessment Software Module (compatible with aviation safety requirements, SAE ARP4761 and other standards) and MMEL (Master Minimum Equipment List analysis for aviation industry).
Event Tree Analysis (ETA)
Event Trees are one of the most widely used methods in system risk analysis. It is an inductive failure analysis performed to determine the consequences of single failure for the overall system risk or reliability. Event Tree Analysis uses similar logic and mathematics as Fault Tree Analysis, but the approach is different – FTA uses deductive approach (from system failure to it’s reasons) and ETA uses the inductive approach (from basic failure to it’s consequences). An event tree itself is a visual representation of single failure sequences, it’s influence on other events and on the whole system.
Main window of the RAM Commander Event Tree Analysis Module
ETA Module Features
- User-friendly and convenient tree building interface (zoom, export to clipboard as metafile, print, etc.)
- Customisable graphical representation (diagram elements colours, styles etc.)
- Events Library
- Event Probability assessment models:
- user-defined
- calculated (repairable/unrepairable/constant mission time/periodical tests)
- linked to product tree element
- linked to FMECA Failure Mode, NHE or End Effect
- linked to Fault Tree basic event
- linked to Fault Tree gate or tree top event
- Different Event logic types:
- Binary logic
- True/False
- Success/Failure
- Multiple alternatives (for events where not only True/False or Success/Failure outcomes are considered)
- Binary logic
- Different Event probability types
- Equal event probabilities in all sequences
- Different event probabilities in different sequences (conditional probabilities)
Safety Assessment – based on SAE ARP4761
The safety assessment process has fundamental importance in establishing appropriate safety objectives for the System Under Analysis (SUA) and determining that the implementation satisfies these objectives. The safety assessment process is iterative by nature; using RAM Commander to support all necessary iterations and to produce all required output is the easy, accurate and time-saving way to do the safety assessment.
RAM Commander Safety Assessment Software Module implements tasks of qualitative and quantitative safety assessment required during system development:
• Generation and verification of safety requirements;
• Identification of all relevant failure conditions;
• Consideration of all significant combinations of failures causing failure conditions;
• Generation of output reports starting from the stage of Functional Hazard Analysis (FHA/PHA) and ending by the System Safety Assessment (SSA) verifying that the design meets safety requirements. Reports are generated as MS Word documents using customisable MS Word templates.
• AFO (Russian standard required by AR MAC) support
• System Hazard Assessment and O&SHA according to MIL-STD-882. Reports are generated as MS Word documents using customisable MS Word templates.
Master Minimum Equipment List (MMEL)
The Master Minimum Equipment List (MMEL) is a document which lists the equipment that may temporarily be inoperative, subject to certain conditions, whilst maintaining an acceptable level of safety as intended in the applicable documents. Each MMEL document is specific to an aircraft type.
MMEL analysis is required for all aircraft manufacturers to certify aircraft safety in different aviation authorities such as FAA, EASA etc.
RAM Commander integrated MMEL module supports Master Minimum Equipment List generation using Reliability, FMECA, FHA (Safety) and FTA modules results.
Below is an example of standard MMEL 5-column report as generated by RAM Commander:
RAM Commander’s MMEL module main features:
• Compliance with MMEL requirements
• Integration with aircraft Reliability and Safety analyses modules
• Candidate Item selection
• Calculation(s) of Expected Probability before and after failure
• Automatic identification of the next (first in flight) and second worst failures
• Reports generation:
• Standard MMEL: “Five Column Format” – presents the standard MMEL report
• Detailed Quantitative Analysis – presents results of analysis on which MMEL selection has been made
MMEL module provides several algorithms for MMEL candidate selection:
• Algorithm based on JAA MMEL development guidelines
• Algorithm implementing RRJ – 95/75 guidelines
User may select appropriate algorithm for system analysis.
Please contact us for further information on any of our products and services or if you simply wish to find out how RAM COMMANDER can help your organisation.
Functional Packages
PREDICTOR
- 5 Standard Operating Reliability Prediction Methods
- BOM Builder, Temperature Curves, Mission Profile, and Import Wizard
- Full set of ready-to-print Reliability Reports
- Enhanced Report Generator for user defined reports
RELIABILITY PRO
- 5 Standard Operating Reliability Prediction Methods
- BOM Builder, Temperature Curves, Mission Profile, and Import Wizard
- User Defined Components Reliability Data Module
- Full set of ready-to-print Reliability Reports
- Enhanced Report Generator for user defined reports
- Components Library Module (over 400k components)
- RBD – Reliability Block Diagram
MAINTAINABILITY PRO
- Maintainability Module (according to MIL-STD-472 Procedure 5A)
- Built in libraries for Tasks, Times, STE, Skills, and Materials
- Maintenance Engineering Report (MEA Report)
- Maintenance Task Analysis Report
- Full set of ready-to-print Reliability Reports
- ILS Supprt Fields (user defined)
- BOM Builder, Temperature Curves, Mission Profile & Import Wizard
- Enhanced Report Generator for user defined reports
- RCM/MSG-3 Module
- FMECA Module
FAILURE ANALYSIS & ISOLATION
- BOM Builder, and Import Wizard
- FMECA (covering both Hardware & Functional) Module
- Customizable FMECA Worksheet
- FTA Module
- FMECA Import/Export
- Testability Module
- Full set of FMECA & FTA ready-to-print Reports
- Full set of ready-to-print Testability Reports including graphical trouble shooting, fault isolation, etc.
- FMD-97 Library
- Enhanced Report Generator for user defined reports
SAFETY ASSESSMENT
- SSA supporting IEC 61508 (Safety Standard for Safety Instrumented Systems) and MIL-STD-882D (SHA, O&SHA), SAE, ARP 4754A, and ARP4761
- Customisable FMECA Worksheet
- FTA Module
- RBD Module
- Markov Chains Module
- FMECA Import/Export
- Full set of ready-to-print Safety Reports
- Enhanced Report Generator for user defined reports
AVIATION SAFETY
- SSA & FHA according to SAE, ARP 4754A, ARP4761, and FAR 25 1309b
- FTA including ready-to print reports
- MSG-3 (System, Zonal, and Structural) including ready-to-print reports
- MMEL including ready-to-print 5-column report
- FMECA including ready-to-print FMECA reports, BOM Builder, and Import Wizard
- Enhanced Report Generator for user defined reports
- Report Template Utility for layout customisation