Attack Tree Analysis Understanding and modelling threats

In today’s increasingly interconnected world, system hazards are more likely than ever to originate from deliberate attacks, such as hacking and malware.

Using the example of how an attacker could gain access to on-board systems in a car by hacking into the entertainment system, this webinar will show how attack tree analysis, a modified form of fault tree analysis, can be used to predict the frequency of a threat due to attacks on a system and the failure of defensive measures.

We will also demonstrate how attack tree analysis can take into account the impact of a successful attack on factors such as cost and safety, as well as the cost and difficulty incurred by the attacker.

Included is a web demonstration where we will address modelling these threats in AttackTree+:

As always please feel free to contact me if you have any questions.

Best Regards, Jeremy

Building a fault tree from a schemtic

Included is our most popular webinar to date, where we will took the included schematic, of a propulsion system, and demonstrated the logic used to represent this schematic in a Fault Tree. Although there is more than one way to skin a cat, our Fault Tree expert created what he sees as the most logical model to represent this system.

For the ambitious I would suggest that you build your own model in FaultTree+ prior to viewing the meeting and see how your model matches up with ours. For those using demonstration versions of the software you can build the model and save the image using “Print Screen”.

**HINT** in this example, the Fault Tree will look much simpler than the schematic. Watch for common cause failures.

Monopropellant propulsion2 (2)

Please let me know if you have any questions about this Webinar, it will be well worth your time. As always this is not a sales focused web meeting it will be an educational webinar focused on the technical aspects of building a Fault Tree.


Best Regards, Jeremy


Availability Workbench; RCMCost, AvSim, ERP portal

Although we post a lot of web demos that cover analytical topics related to the Reliability Workbench let’s remember that the Availability Workbench is probably the most powerful tool of its kind on the market. There is a good chance someone you know is using the Availability Workbench!

Availability Workbench is used to optimise maintenance and spares policies, predict system availability and throughput and estimate life cycle costs. It includes well known modelling methods such as FMECA, Reliability Block Diagram Analysis and Fault Tree Analysis.

The following web demo is a high level overview of the software, if you have any questions or need more information on the software please let me know:

Reliability Workbench FaultTree+ general overview

Following feedback from users, it seems as though we can never post enough FaultTree+ web demonstrations. Included is general overview of our popular FaultTree+ software. In addition to an explanation on how the tool is used we have also added some useful information on import/export, search functions, customising the grid view,  calculation options, approximation methods, Markov….ext.

As always if you have any questions on the web demonstration or need additional informaiton on our software products please feel free to contact me.

Best Regards,



Weibull Analysis 101

For anyone that has spent a bit of time in reliability the term Weibull distribution has probably come up, or should have come up. It is named after Swedish mathematician Waloddi Weibull, who was the first to describe Weibull in length in 1951. Although Waloddi didn’t actually come up with the math for Webiull, the formulas and even an application had been applied years before,  he was the first to describe it and won the honour of having the Weibull distribution named after him.

Weibull Analysis is used to analyse historical failure data and produces failure distributions that we use during a system simulation.

The Weibull Analysis module of Availability Workbench analyses historical failure and repair data by assigning probability distributions which represent the failure or repair characteristics of a given failure mode.

The failure distribution assigned to a given set of times to failure (known as a Weibull set) may be assigned to locations in the RCMCost location hierarchy or failure models in the AvSim module.

The Weibull Analysis Module analyses times-to-failure and time-to-repair data using the following distributions:

Exponential Distribution
1-Parameter Weibull Distribution
2-Parameter Weibull Distribution
3-Parameter Weibull Distribution
Lognormal Distribution
Normal Distribution
Phased Bi-Weibull
Phased Tri-Weibull

I have included a recorded webinar giving a general Webull overview. We of course do not go into detail on the formulas used. If you would like additional information please contact me: 


Best Kept Secret in Isograph’s software

Secret might be the wrong word to use here, it could be a matter of just asking myself or technical support the right questions. Even if you’ve been using Reliability Workbench, Availability Workbench, AttackTree+, or Network Availability Prediction for years, you’re probably still finding new features and tips and tricks to help you out in the software. Maybe one day you discovered a time-saver and thought to your self “what else can this software do to make my day easier?”

While there are plenty of helpful features in Isograph’s software to make your day easier, perhaps none is so powerful, incredibly useful, and so under-utilized as Plugins and the DLL. These features allow you to extend the power of Reliability Workbench, Availability Workbench, Attack Tree, and NAP tools to absurd heights. From creating macros for accomplishing tedious tasks, to automating fault tree construction, and even adding new features to the software that we haven’t even thought about, the Plugins and DLL can do it.

As always if you have any questions or need additional information on our products please feel free to contact me

Jeremy Hynek
Isograph, Inc.
801 610 0045

Diverse CCF models in FaultTree+, presentation from RAMS 2017

Some of you might have noticed we have introduced a new website. This will allow us many advantages over the old site, however, the blog posts have been delayed a bit.

We recently attended the RAMS symposium in Orlando Florida. Where Joe Belland presented his paper on “Diverse CCF in Fault Trees”.




A full copy of this paper is available:

Diverse CCF in FT -Final

Inside conversation on the SAP portal

SAP can be a great tool for collecting data, however, that data often gets over looked or instances get looked at one by one. Often engineers  wonder what to do with all of that great data collected in SAP? Using the Availability Workbench’s certified SAP portal one can import data regarding PM intervals, spares, labour or any other fields that are applicable to the availability, maintenance or reliability of your system.

I have recorded a recent internal meeting regarding the options and benefits offered by Availability Workbench SAP portal.  As always please let me know if you have any questions or need additional information on the portal,


Isograph is an SMRP Approved Vendor

Isograph is pleased to announce that we have been accepted as a SMRP Approved Provider. If you are not familiar with SMRP (Society of Maintenance and Reliability Professionals), but are interested in maintenance, reliability, availability as well as learning various industry techniques for figuring how to approach your maintenance and reliability. Its worth you time to take a look at this nonprofit professional society. .

Going forward, if you attend either our Availability Workbench RCMCost or Availability Workbench Avsim courses you will receive 8 hours per course towards your CMRP continued education.

For additional information on our training courses: TRAINING

For more information on the CMRP certification: CMRP

The Approved Provider Education Program recognizes continuing education that aligns with the most relevant topics and best practices in the industry according to the SMRP Body of Knowledge and/or the Asset Management Landscape, which is published by the Global Forum on Maintenance and Asset Management (GFMAM).

The program serves as a resource for professionals looking for training and continuing education that is verified by a qualified third party. For Approved Providers, the program offers validation and recognition of their training and educational courses….” (

How To Use Your Settings in Reliability Workbench (FaultTree+)

We have collected commonly asked questions by our 1000′s of users. Some of the questions that we’ll answer along the way include:
Why do my cut sets show gate names with an asterisk next to them?
OK, so I enter a “failure rate.” Is that failures per… hour? Year? Geological epoch? What are the units?
This fault tree takes ages to calculate. Can I speed it up?
Fault tree uses approximation methods for solving the tree? Do I have any control over that?
My computer crashed and I lost 3 hours of work! Can I create automatic backups of my project?
What if I want to see MTTF on my fault tree, instead of Q?
I have a plotter. How do I print the whole tree on one piece of paper?
Can I force scientific notation in the results?
What if I don’t want to delete the inputs to a gate when I delete the gate?
I really love the font Comic Sans. Can I use that in my fault tree?
Also, chartreuse is my favorite color. How do I set that as default?
How do I set default options, so I don’t have to reset these every time I start a new project?

We’ll also look at the useful and often-overlooked Report Options. Did you know that you can force the diagram to be black & white for printouts? Or make the fault tree symbols bigger? Or change the order of the pages?