This spring there will be a lot of activity in Las Vegas. Some will be calculating their losses from March Madness, others will be finishing Spring Break with a yard of ale on the strip and David Wiseman and I will preparing to present our paper “Monte Carlo Simulation as an Aid to Optimization” at this years Reliability 2.0 conference. Reliability 2.0 Agenda April 7-11, 2014
Monte Carlo simulation techniques allow computer programs to emulate plant behavior and quickly assess the effects of alternative PM policies. In this presentation we will demonstrate how to optimize PM intervals. We will also show how simulators may be used to optimize spare part storage levels – a vital consideration when restocking is subject to long lead times. Such optimization techniques can help to reduce maintenance and spare part storage costs, while taking into account safety, operational and environmental risk.
Isograph will be supporting this years Reliability 2.0 event by presenting 2 papers and exhibiting at the conference.
Howdy, folks! Welcome back to another Tech Tuesday. For our US clients, I hope you enjoyed your President’s Day weekend. I certainly did enjoy spending the day with my new daughter.
I’m back in the office and it’s business as usual, now, so I thought I’d take this time to write about the copy protection used by Isograph.
Isograph’s software uses FlexNet Publisher by Flexera Software. This is a very popular copy protection tool, used by many companies, such as Adobe, to maintain copy control. Most companies, it seems, already have a FlexNet license server set up. Some of our users also remember it when it was called FLEXlm or Flexible License Manager, and was developed by Macrovision. Either way, it’s a very commonly-used tool.
Isograph has used FlexNet licensing in our products since 2004, starting with our Network Availability Program (NAP) v1.0. In 2007, with the release of Availability Workbench 1.0, we switched to what is known as FlexNet trusted storage services. Now, the latest releases of Availability Workbench, Reliability Workbench, and Hazop+ all use trusted storage services via FlexNet 11.
See, the FlexNet that most people are used to uses what is known as certificate-based licensing. In this method—used by our legacy programs, such as NAP and AttackTree+, and older versions of Reliability Workbench, FaultTree+, and AvSim+—a license certificate, typically just a text file with a long code in it, is used to activate the software. This text file is created by Isograph based on some information from the computer that the user intended to have licensed. Many software vendors use the MAC address, or network address, but Isograph’s certificate licenses used the “composite host ID” which was based on several internal components of the computer, including the hard disk and network card. This way, the license file would only activate a single computer—the one it was created for. To activate the computer, the license file just had to be placed in the program’s directory.
The drawback to certificate-based licensing is that it’s difficult to move the license; it’s generated for a specific machine, so to move the software to another machine, you had to contact Isograph for another license. And because this could be abused, we typically asked for a written statement saying that you would delete your old license when you received the new one. We also ran into a few issues in some cases, where changing the computer’s components would result in the license no longer working. For instance, switching from a wireless to a wired network, or plugging a laptop into a docking station would fool the FlexNet service into thinking that it was now on a different computer, one that had not been licensed.
But as I mentioned, starting in 2007, we moved to FlexNet trusted storage licensing. In this method, rather than you giving us an identifying number from your computer, we simply give you a code called an activation ID. To activate your license, you simply copy and paste this code into the software, and it will connect to our license server over the internet and activate your license. Once this initial connection and activation is complete, no further contact with our servers is needed.
The advantages to this are many; you don’t need to wait on us to activate or move a license. If you decide you’d rather move the license to another computer, you can do it yourself very simply. It also works well with upgrades. Previously, if you needed an upgrade license, we would ask for written confirmation that you’d deleted your old licenses. Now, you can just return your licenses over the internet, and we’ll be able to see that you’ve done that. In fact, with the latest version of FlexNet publisher, upgrades can be done automatically. We’ll issue you an upgrade activation ID and when you activate it, your previous-version licenses will be automatically returned.
For users without an internet connection, which is common with servers or secure computers, trusted storage licenses can also be activated via request and response files. Basically, the same information that’s sent via a web connection can also be sent via email. You’ll enter the activation ID into the software, and generate a requestXML file, which you’ll email to us. We use this file to create a responseXML file which we send back to you. You’ll process this response file and the license is activated. Licenses can also be returned and re-hosted using this method.
And for users with highly-secure computers, from which you can’t remove any files—this is common for top secret government or military contractors—we can still fall back on certificate-based licenses, where you’ll only need to send us the MAC address.
Next week, I’ll talk more about FlexNet license servers, the newest version of the FlexNet publisher server software, and the differences between LMTOOLS and LMADMIN for configuring the server.
We are happy to announce that Dow Chemical will be hosting Isograph’s FaultTree+ IEC 61508 training again this year in Deerpark Texas near Houston on April 29th and 30th, 2014. Last year’s class sold out quickly so be sure to save a spot in this class. Depending on your industry there are several adaptations of the IEC 61508 which include: the ISO 26262 for automotive, the IEC 61511 for SIS in process safety, the IEC 61513 for Nuclear power, IEC 62279 for Rail Software as well as many others. Basically if you are calculating System Integrity Levels (SIL) or Safety Instrumented Systems (SIS) we have you covered.
This two-day course will give users a brief overview of fault tree methodology, then focus on the many features in Reliability Workbench 11.1 designed to assist with safety instrumented system/safety instrumented function analysis according to IEC standard 61508.
Congratulations to our North American Technical Lead, Joe Belland, who is out on paternity leave for a couple weeks. If your curious about what Joe is up to we had him breakdown his week in the fault tree diagram below. Although Joe will be missed for the next few weeks its business as usual here at Isograph North America. Joe and our support team will still be responding to support questions via email email@example.com and Jeremy Hynek will be answering Joe’s phone 949 502 5749.
Joe wasn’t able to write his weekly column before his baby girl was born, but he did put together this Fault Tree explaining why he might be in and out of contact for the next few weeks.
Today I would like to address one of the most commonly asked questions by new users of our FaultTree+ software, which is: Copy and Paste vs. Copy and Paste Special. When used correctly Copy and Paste and Copy and Paste Special can be a huge time saver. If used incorrectly this feature can unintentionally be introducing Common Cause Failures (CCF) which can kill the reliability of a system or create copies of existing events or gates, which were intended to be CCF, making your tree more reliable than it should be.
Copying and Pasting a gate or event will cause the same gate or event to appear in different parts of the tree. Pump1 will be our example, if we Copy and Paste Pump1 from gate GT1 and paste that pump under gate GT3. Pump1 would now be listed under 2 separate OR Gates.
As you can see in the example below the event named Pump1 has been Copied and Pasted under gate GT3. The event Pump1 has the exact same name in both events making Pump1 a CCF. Using Copy and Paste is representing the same event in two different branches of this fault tree.
Copy and Paste Special on the other hand creates a copy of Pump1. This is not the same event but an identical event. As you will see below I have used Copy and Paste Special to add a copy of Pump1 under gate GT1 to gate GT2, the new identical pump is named Pump2 not to be confused with the event Pump1 under gate GT1 and GT3 . Pump2 is an identical in every way to Pump1 but is not the same pump. In this case Pump2 would not create a CCF. Please note that when using Paste Special the software has automatically renamed event Pump1 to Pump2. The new gate or event can use any naming convention you would like as long as it is not the same name as an existing event. When 2 gates or events have the exact same name the software recognizes those gates or events as the same gate or event.
Howdy, folks. This will be the first installment of what we hope will become a regular feature around here. Each Tuesday, look for an article highlighting a technical aspect of our software. This may be a demonstration of a feature, an explanation of the mathematics that power the tools, or some comments on technical support questions that we’re frequently asked.
Today, I’ll be talking about the Grid Control feature of our Availability Workbench and Reliability Workbench tools. If you’ve used our AvSim or FaultTree+ software, you know the power of the tool, and the usefulness of the diagram view to be able to create and edit intricate Fault Tree or Reliability Block Diagrams (RBDs). However, sometimes you may find that you have to do some task, such as text entry, or finding and replacing some information, that can be cumbersome to perform in the diagram view.
For instance, suppose you’ve created a large, multi-page Fault Tree, and now you want to add unique IDs and descriptions to all the gates and events, so you can identify what each one represents. To do this in the diagram view, you’d need to locate each item individually, double-click to open the Properties dialog for the gate or event, set the ID and description, click “OK” to close the dialog, find the next item, rinse, and repeat. There’s a lot of back-and-forth between mouse and keyboard, and hunting through the diagram for the items you want.
The Grid control helps with this by providing a tabular format for editing data, similar to what you’d see in Microsoft’s Excel or Access products. Each gate or event appears on one line of the grid, and you can use the cursor keys, or the tab key, to navigate the records and fields. To edit some text, simply highlight a field with the mouse or keyboard and start typing, or press Enter on your keyboard.
From the grid view, you can use the table selector to choose which data you want to display. This might be the Gates, Events, or Failure Models table in FaultTree+ , or the RBD Blocks or Failure Models table in AvSim.
With a given table selected, you can refine which records should be displayed by using the “Filter Grid by Tree Control Selection” option, found in the Grid menu. This mouthful-of-a-name simply means that data will only be displayed in the Grid if it’s relevant to the selection in the tree control on the left hand side. For instance, selecting a particular gate in the Fault Tree hierarchy will only show events under that gate, or selecting a Failure Model group in the AvSim project will only display failure models in that group.
There are plenty more options in the Grid view that allow you to choose what data is displayed. You can use the Grid Layout options to choose what columns should be displayed, and what their order should be; the Grid Filter provides further methods of filtering records; and the Grid Sort allows you to choose how the records are sorted. And any custom grid layout, filtering, or sorting you’ve created can be saved, so you can share it with your colleagues or transfer it to a new computer. You can even copy and paste data directly from the Grid view to a spreadsheet application like Microsoft Excel.
There’s even a Find & Replace feature, for when you need it. The cool part is, when you use Find & Replace, it will only apply to the currently-displayed records. If you use a filter to hide certain rows, they won’t be included in the replacement.
And for those times when you want the Properties dialog, you can just double-click the grey space to the left of a grid row to open the Properties dialog for the item.
Why don’t you take a look at the Grid control, and try it out? I’ve found it to be a great tool to use when quickly building or editing a project.
For those of you working today I thought I would give a little background on Monte Carlo Simulation (MCS). I have to admit that when asked I have tied MCS back to the gambling industry more than once. It sounds like a good story, however, it turns out the name comes from the resemblance to the act of playing and recording your results in a real gambling casino. MCS techniques are often used in physical and mathematical problems and are most useful when it is difficult or impossible to obtain a closed-form expression, or in-feasible to apply a deterministicalgorithm. Monte Carlo methods are mainly used in three distinct problem classes: optimization, numericalintegration and generation of draws from a probabilitydistribution.
The modern version of the Monte Carlo method was invented in the late 1940s by StanislawUlam, while he was working on nuclear weapons projects at the Los Alamos NationalLabs. It was named by NicholasMetropolis, after the Monte Carlo Casino, where Ulam’s uncle often gambled. Immediately after Ulam’s breakthrough, John VonNeumann understood its importance and programmed the ENIAC computer to carry out Monte Carlo calculations.
So although gambling is a reference it’s not the reason for or used in the gaming industry… we at Isograph use MCS techniques to solve problems that cannot be solved using quantitative methods. Optimizing Preventive Maintenance Intervals, deciding the perfect number of spares to have and where to keep them as well as optimizing the configuration of your system are just a few of the problems we can solve with the Availability Workbench using Monte Carlo Simulation. However, we cannot tell you where to place your bets or what number to choose on the Roulette Wheel.
The following is a short demonstration as to how we use MCS together with FMEA’s for RCM analysis or Block Diagrams to model complex systems logic.
For almost 2 decades Isograph has been supporting the RAMS conference in various locations around North America. The week of January 27 Isograph will again be attending RAMS 2014 which will be held at The Broadmoor Hotel in Colorado Springs, Colorado. In addition to the exhibits the conference will offer tutorials, technical presentations, CEUs and certifications such as the ASQ Certification Exams – ASQ Certified Reliability Engineer (CRE), Certified Six Sigma Black Belt (CSSBB) and Certified Six Sigma Green Belt (CSSGB).