3.3 RAMS tools and software modules
3.3.7 System data tools
There are several types of data required for reliability analyses and thus need to be stored in tables or databases of reliability software. RAMS software modules, in general, include parts table for storing the list of system components, general data tables and descriptions, as well as tables for calculation data. The latter one covers the data provided by the company to serve as the basis for reliability calculations, and the calculated or predicted data.
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40 3.3.8 Event tree diagram
The events that may occur in the system can be visually represented as event trees. They can be used to analyse both continually operating and standby systems. The branches of trees represent the success or failure of the components in the system. An event tree consists of
• Initiating event: the very first event (column) that starts the sequence of events in the event tree. In continuously operating systems, it is usually the event that disrupts normal system operation.
• Columns: events in the event tree. By representing an event, a column also represents one step in an event tree sequence.
• Branches: a branch defines the status of an event.
• Consequences: the outcomes expected when a particular sequence of events occurs. In the event tree, consequences are assigned to each terminating branch. The consequences represent what will happen if the event sequence that ends with this terminating event occurs.
• Sequences: the combinations of events that result in the occurrence of a certain set of consequences, e.g. success sequences or failure sequences.
3.3.9 Predictions
The aim of reliability prediction is to define the failure rate for all considerable components in the system and obtain an overall system failure rate. The result is an estimation of overall system failure rate and future probability of failure. The calculation models for various component types are based on test data. With few exceptions, these models assume a constant failure rate with time to address the useful life of components where failures are regarded as random. Reliability predictions can often be represented graphically as the simple graph of the bathtub curve (Fig. 1.5).
Maintainability prediction can help engineers to predict the time requirement to achieve 100%
maintainability. The Author has original contributions to this field (Klemeš et al., 2009b; Sikos and Klemeš, 2009d).
3.3.10 Analytical methods versus simulation
A calculation method is called analytical when results are computed using formulas derived from some kind of mathematical analysis. This algebraic approach obtains the probability density function analytically from the failure distribution of each component using probability theory. It determines a mathematical expression that describes the reliability of system components. In general, analytical methods are accurate and reasonably fast. However, they are feasible only if there are no complex dependencies within the system.
A different method is required when results are computed by considering the dynamic behavior of the system, even through various inputs. It is known as simulation. It generates random failure times from the failure distribution of each component (Fig. 3.5).
In reliability engineering, there is more or less randomness in the system behavior. Thus, to observe this behavior, random numbers are required as input data. Simulation that involves random numbers is the well-known Monte Carlo simulation. Simulation can be used for analysing any kind of system. However, the accuracy of the results depends on the number of iterations and the complexity of the system. Analytical methods based on advanced algorithms are generally quicker and produce more accurate results than simulation. Therefore, if possible, it is better to apply analytical methods. If there is a need to consistently and accurately calculate failure probabilities of less than 10-5, analytical solutions are needed. However, if analytical results are infeasible or too complex, simulation should be used.
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Figure 3.5 Simulation of unreliability in SimuMatic, a Weibull++ extension.
3.4 Software groups
In order to consider the specific features of the scenario to be modelled and optimised, care must be taken to choose the appropriate software packages or tools from the right software group. Sometimes a simple reliability tool is adequate, while at other times it is not enough. However, applying the most complex RAMS packages is not necessarily the best solution in each case. Furthermore, the wide range of features and services might be improved via using packages or tools from various software groups in combination (Sikos and Klemeš, 2009a). In many cases, however, the development of own software is still the best solution.
3.4.1 Availability software
Availability depends on many features, including design, the way of operation, fuel etc. It can be treated together with reliability and life cycle cost modelling as they are influenced by each other. This is a common approach in many modern software packages.
Table 3.2 summarises the main features of some widely used software packages and tools.
Some of them can be purchased individually while others are complex packages, including several modules and embedded tools. Some developers offer several availability software tools or packages. Large companies providing more than one availability tool are often known for reliability and maintainability tools and packages as well. The accessibility of demo versions and the limitations of these versions are important for evaluation purposes. On the website of the developer or software vendor there are descriptions of the features and capabilities of the software tool or package, along with nice brochures. However, they are often encapsulated with business driven advertisements.
Availability software has a long history. Successful applications in industry are already known for decades (e.g. Klemeš and Krus, 1985).
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Table 3.2 Some availability packages and related software tools.
Software or package Company
or vendor
Demo accessibility/
restrictions of demo Website
Availability Workbench Isograph Ltd. Demo. Project size and save limitations
AvSim+ Isograph Ltd. Demo. Project size and save
limitations
CAME BQR Reliability Engineering
Ltd. Demo (30 days)
COMPARE Maintenance 2000 No demo.
MEADEP SoHaR Corporation Demo/online demonstration
PLASMA Maintenance 2000 No demo.
RAMP Reliass Demo. Time limit.
3.4.2 Shutdown and turnaround management software
Plant maintenance shutdowns require careful planning, scheduling, and control. Shutdown management software can help this process with multiple shutdown scenarios, shutdown job plans and job steps creation, automatic scheduling, shutdown resource management etc.
Turnaround management software tools are plant-wide information systems for outages and shutdowns. As examples can serve: Cobra, APT-SCHEDULE, ATC Professional, Contractor Cost Tracking System, DataPath, RationPlan, RB.eye, Turnaround Manager.
3.4.3 Reliability software tools
Reliability is one of those design and manufacturing inherent features that are strongly influenced by operating conditions. These parameters can be handled by specific software tools. Reliability software suites contain prediction or analytical modules, or both. They have standardized critical functions and are capable to model complex system scenarios (e.g., parallel, standby, bridge, network), quantify risk and ensure safety, control corrective actions, build FMEAs, and determine optional system parameters for maximum performance. They control all analyses with the centralized navigator, and support database connectivity (Micro-soft Jet Engine, MSDE, Oracle, SQL Server etc.).
Their integration levels are high, containing widely used standards and methodologies to analyse systems or components and increase safety.
Modern reliability analysis tools offer multiple system analysis, project file sharing, results comparison, component or system drag and drop between projects, as well as quick new project creation by reusing components from other systems.
GUIs make it easier and faster to use the components or the whole system, hierarchy trees, charts or graphs, automatic chart generation through a wide variety of powerful wizards. Table 3.3 presents the main features of several software packages.
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Table 3.3 Specific reliability packages and related software tools.
Software/ package Company
or vendor
Demo accessibility/
restrictions of demo Website
Analyst Powertechnic Pty Ltd Cannot save files, maximum
of 10 components.
GoldSim Reliability Module GoldSim Technology Group Demo. Unlimited version, valid for 30 days.
RAMP Reliass Demo.
RAPTOR ARINC Freeware. No restrictions.
RelCalc for Win. T-Cubed Sys., Inc. Demo. Limited capacity.
RELCODE OMDEC Demo. No restrictions.
RiskVu Isograph Ltd. Demo. No project save,
project size limitations.
SAPHIRE Idaho National Laboratory Demo. 60 days trial version.
SIMFIA APSYS Demo. Impossible to save.
SPIDR System Reliability Center Demo. Contains a data
subset representative of the actual data contained in the full version.
An impressive example for reliability software is SAPHIRE, a low-cost probabilistic risk, safety, and reliability tool. Based on fault and event tree logic models, it allows the quantification of system, sequence, and end state outcomes. Unlike many other reliability tools on the market, it has been investigated by scientists (e.g., Faghihi et al., 2008; Smith et al., 2008).
3.4.4 Safety and environmental maintenance software
A wide variety of industrial plants and power generators have one feature in common: they are dependent upon high quality maintenance.
Managing optimum maintenance is a broad, complicated and time-consuming task.
Maintenance software tool track many issues to let maintenance managers know exactly what kind of maintenance is needed and when. With the help of the right software tool it is possible to prevent problems from occurring. Software tools offer additional features as well. They include the database of users and vendors, a built-in invoicing system, or a scheduled task system. Some examples: AMMS, AUDITWorks, CIRSMA, SafePro, Tracker.
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44 3.4.5 Failure analysis software
Failure analysis requires data collection and analyses to determine the failure cause and how to prevent it from happening again. These tools can be used in the development of new products and for the improvement of existing ones. Examples of failure analysis software tools are: AAP606, ASENT FRACAS, CAME-FDA, FaultTree+, FMEA-Pro, Meridium, MKV, QTMS, RDA Utility, Ttree.
3.4.6 FMEA/FMECA software
Failure Mode Effects (and Criticality) Analysis are performed as design processes which should eliminate or even reduce failure modes with high probability and severity. This analysis is a complex task, which includes several techniques, e.g. mechanical reliability predictions, determining the effects of system and equipment failures. Examples of FMEA and FMECA software tools are: FMEA-Pro, FMECA Plus, FMECA Processor for Windows, Maintenance Analytics, MEAnalyst, Manifer, Meridium.
3.4.7 Computerized Maintenance Management System (CMMS) software
A CMMS software package (also known as Enterprise Asset Management) maintains a computer database about maintenance operations of companies. This information may be capable to improve the effectiveness of the work of maintenance engineers. It can be also helpful to make well informed decisions and deal with third parties.
CMMS software can keep tracking preventive maintenance schedules, service contracts, problem reports, and material inventories. Managers can allocate people and resources more effectively while workers can eliminate wasted time and effort.
Some examples for CMMS software:
• AIMS is a complete CMMS solution that keeps track of maintenance and repair activities within organizations. It increases labour productivity while aiding efforts to meet certain regulatory requirements.
• AMMS WIN is an easy to use, corrective/preventive maintenance and calibration system with fully integrated inventory, purchasing, labour scheduling, budgeting, graphics, bar-coding and networking features. There is an option for user customisa-tion. It is capable to populate databases, create ad-hoc reports and forms. Imaging option allows viewing and printing scanned drawings, diagrams or procedures for individual equipment and parts on work orders and purchase orders. The system is fully barcodable and networkable. Options are available that provide, among others, an interface to connect other purchasing, financial, predictive maintenance and office products. Maintenance and support, training implementation and software customisa-tion services are also available.
• Assembly Vision is an easy to use maintenance management system and knowledge base for sharing equipment information between the maintenance, production, quality, safety, and engineering departments of companies.
• Asset Controller is maintenance management software that automatically schedules preventive maintenance. It supports work orders trackings and equipment unit purchase.
• Assetintegrity.com allows companies to track their equipment maintenance, spares inventory and warranty details, providing full historical records. Version 3 has the ability to handle equipment requirements over multiple sites. It can be used online for a small monthly fee or leased on for a complete purchase.
• Cedar is the software for maintenance management and productivity improvement designed to match the level of maintenance maturity from execution, planning and
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management. Customers can select and start implementing from entry to advanced level.
• COGZ CMMS integrates preventive maintenance, work orders, inventory control, and purchase order management. COGZ supports building maintenance, facility maintenance, fleet maintenance, vehicle maintenance, plant maintenance, equipment maintenance, and preventative maintenance.
• Cworks is a complete solution for CMMS. Users are able to manage work orders, assets, locations and preventive maintenance with ease and assurance. Full source codes are provided with the full professional version.
• Davision Maintenance relates corrective work orders and preventive maintenance tasks to equipment components. Any combination of parts (stock inventory) is related to equipment, work orders, or predictive maintenance tasks by part group. Management reports accumulate costs and personnel hours in various formats to help organizing and saving personnel time and equipment costs.
• Easy Plant Maintenance schedules workorders, parts, procedures, photos, and keeps detailed records and video of all maintenance actions. Useful software for maintenance improvements.
• Exp – Preventive Maintenance Expert is a simple to use and affordable preventive maintenance software solution for growing companies. Exp aids in the process of servicing equipment and ordering replacement parts.
• Maintenance Assistant is full-featured CMMS software that suits for industrial purposes.
It integrates maintenance management features, and includes an intuitive user interface.
• Mantra is developed for planned maintenance scheduling, job history including planned, unplanned and breakdown, jobsheet issuing, and stock control.
3.4.8 Maintenance audit software
If a maintenance plan is required, the process of performing the routine actions, which keep the device in working order, should be audited. Most maintenance audit software tools are aimed at work order entry, equipment history, and accounting. Some of them may help measuring current productivity, setting productivity goals and tracking the process toward these goals. Examples of such programs are Aware.MPS, Aware.MNT, Easy Audit, infoRouter, ON KEY Auditor, PEMMS, UmtAudit, xmEXEC.
3.4.9 Spare parts analysis and optimisation software
Spare parts (also referred as service parts or spares) are the extra parts available in the proximity of the item of a given system for which they might be used. The analysis and optimisation of spares is the main concept of the strategic service management. It can be used to ensure that right spares are at the appropriate place at the right time. The software tools APT-SPARES, AvSim+, CAME-S2A, CARE, FMEA-Pro, Integrated Spares and Logistics Evaluator, and VMetric can be listed as well-known examples.
3.4.10 Tool control software
Tool control software tools track vital assets and tools, providing a detailed audit trail for check in/check out, minima and maxima for ordering, and calibration tracking with detailed history, issue and return functions, inventory and ordering, re-work, kit building etc. Some widely used examples: Automated Tool Inventory Control and Tracking System, collectiveTool Crib, ToolHound, CribMaster Inventory Management System, ToolManager TLC32 Pro.
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46 3.4.11 RAM/RAMS packages
The role of CAPE tools is crucial for the analysis of failure data in Reliability, Availability, Maintainability and Safety (RAMS). In waste management, a wide variety of failures has big influence to the correct consideration of failure data. In addition, scheduled outages such as cleaning, supervision, avoidance of fatigue, although not caused by failures, need to be considered too. Some data are difficult to collect and rather sensitive. Collected data should be analysed in many ways. An efficient CAPE approach in this field is to apply a combination of reliability and waste management software packages for the related analyses, calculations and predictions, considering the specificities of waste management failure data.
Some reliability software tools are capable to solve specific problems only. In contrast, complex RAMS packages integrate various modules providing availability, reliability and maintenance services, including:
• Availability Simulation, availability predictions
• Failure Mode Effects and Criticality Analysis (FMECA)
• Reliability Block Diagram (RBD)
• Fault Tree Analysis (FTA)
• Event Tree Analysis (ETA)
• Markov Analysis (MKV)
• Life Cycle Cost (LCC) Analysis
• Reliability prediction
• Maintainability prediction
Some companies offer their software tools both as integrated modules of RAMS packages and separate software tools that can be purchased individually (e.g. ReliaSoft).
Although there is a wide variety of software on the market, it is recommended to use a complex reliability software package for optimisation problems dealing with large amounts of data. Further benefits of these programs are the capability of modelling via various methods and tools, the high accuracy of results, among the possibility to use other helpful features.
Lots of problems can be solved by most of the complex reliability software packages, but in different ways. The main reason to take a closer look at these products is that they contain different modules. In the following sections, an assessment will be made on some promising software suits.
3.4.11.1 Relex Reliability Studio
One of the most promising reliability software packages is Relex Reliability Studio (Relex Software Corporation, 2009b). An example of the workscreen of this software package is presented in Fig. 3.6.
To become familiar with the modules provided by the program, the user should simply execute it. Modules can be selected in the first modal window that appears before the main working screen of Relex Reliability Studio. These modules are: Event Tree, Fault Tree, FMEA, FRACAS, Human Factors, Life Cycle Cost, Maintainability, Markov, Phase Diagrams, Reliability Prediction, RBD-OpSim, Weibull.
The following integrated modules are also available as standalone products:
• Relex: Availability, Reliability & Maintainability Analysis Software
• Relex Event Tree: Relex Event Tree enables the user to easily create complete event trees and perform fast and accurate calculations. It quickly computes the probabil-ity of all the possible outcomes, as well as for the events leading up to them. Relex Event Tree can display the unavailability, unreliability, frequency, availability, and reliability of the undesired event. It creates customizable reports, showing the complete analysis or specific branch data.
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Figure 3.6 Working screen of Relex Reliability Studio.
• Relex Fault Tree: Relex Fault Tree lets the user easily create customizable fault tree diagrams and perform fast and accurate system safety analyses. It offers both graphical and tabular displays, making it easy to edit specific gate properties. Relex Fault Tree supports numerous gate and event types, common cause failure modelling, time dependent analyses, and includes a Minimal Cut Set engine.
• Relex FMEA/FMECA: Relex FMEA/FMECA can handle Failure Mode, Effects and Criticality Analyses with unsurpassed power and flexibility. It supports the FMEA standards developed by the aerospace, defense, and automotive industries, and enables customization. Relex FMEA/FMECA supports risk priority numbers (RPN), criticality ranks, risk levels, criticality matrices, failure mode probability calculations, and exporting to LSAR compatible formats.
• Relex Life Cycle Cost: Relex LCC is a flexible Life Cycle Cost analysis tool that calculates the cost of any product over its lifetime. By taking inflation factors into
• Relex Life Cycle Cost: Relex LCC is a flexible Life Cycle Cost analysis tool that calculates the cost of any product over its lifetime. By taking inflation factors into