The exSILentia reports are dynamically generated in RTF (Rich Text Format). Once you open the report in MSWord select "File" - "Save As" - "Word Document". Once you store the file in the "native" Word format its size will drop drastically (e.g. 80MB to 3MB). Applies to: exSILentia (All versions)  Keywords: Reports

exSILentia has a Parameter Update utility. This utility allows you to change some key parameters for all or a selected set of SIFs in a project. Applies to: exSILentia (All versions)  Keywords: SILver, Change SIF parameter, 61508, 61511

To use exSILentia your system should meet the following minimum requirements
• Microsoft® Windows 2000 or Windows XP (all service packs installed)
• Personal Computer with Pentium 700 MHz or higher processor
• 256 MB of RAM (512 MB recommended)
• 100 MB of free hard disk space
• CD-ROM drive
• Free USB port
• Microsoft® Internet Explorer 6.0 or later
• Minimum screen resolution of 1024 x 768 Applies to: exSILentia Standalone  Keywords: General, System Requirements

User Minimum Requirements:
-Internet Explorer 5.5 with Javascript enabled
-screen resolution of 800x600

User Recommended:
-Internet Explorer 6.0 (or newer)
-screen resolution of 1024x768 or greater

Users must install the Citrix interface agent on his local machine. This may require administrator right access. Citrix ICA client v10 or later should be installed. Applies to: exSILentia Online  Keywords: General, System Requirements

exSILentia Server must be hosted on a Citrix presentation server. Whatever server can run Citrix presentation server 4.0 and up will be suitable to support exSILentia.

In addition Hard Drive Space of at least 1 Gigabytes is recommended

The user requirements are identical to the exSILentia online requirements.
User Minimum Requirements:
-Internet Explorer 5.5 with Javascript enabled
-screen resolution of 800x600

User Recommended:
-Internet Explorer 6.0 (or newer)
-screen resolution of 1024x768 or greater

Users must install the Citrix interface agent on his local machine. This may require administrator right access. Citrix ICA client v10 or later should be installed. Applies to: exSILentia Server  Keywords: System Requirements

Indeed a USB key is needed for the stand-alone version of exSILentia. It is possible however to have the USB key in a server and the software installed on an unlimited number of PCs. When you startup the software, it will look for the USB key, first locally, then on the network. As soon as one user is connected to the key other users will not be able to startup the tool until the first user disconnects. Alternatively you can move the USB key around as you described, both solutions work. Applies to: exSILentia Standalone  Keywords: USB, License

When defining a project within exSILentia users can identify what sub-tools they want to include. If a project only warrants the use of SILver simply deselect the SILect and SIF SRS tool enable checkboxes. Applies to: exSILentia (All versions)  Keywords: SILver, Existing SIL Assessment

We have the option to consider high demand mode for a SIF.
To be more precise we allow you to specify either the demand interval on the SIF, in which case SILver determines the mode the application is in, or define low demand, high demand, or continuous demand.
You define the demand modes on the "Safety Intrumented Function" screen of SILver. Applies to: exSILentia (All versions)  Keywords: SILver, High Demand, Demand Mode

There is a wide variety of equipment available in the exida equipment database. Once you use the SILver tool, you will notice dropdown boxes. All equipment items will be accessible from these dropdown boxes. The equipment database has been published by exida as the Safety Equipment Reliability Handbook (SERH) showing all equipment items that are accessible from the tool, the book is over 500 pages, which will give an indication of the large amount of equipment items available. Applies to: exSILentia (All versions)  Keywords: SILver, Equipment, SERH

The equipment database included in the exSILentia SILver tool contains all the devices found in the Safety Equipment Reliability Handbook (SERH) and all updates. This insures that all SIFs you create will have the most up to date reliability data from exida.

A user can enter custom reliability data by using "MyOwn" devices. At the current time it is not possible to store this data for use in other functions or by other users in the Standalone and Online versions of exSILentia. The Server version of exSILentia can be purchased with the option to have a Custom Equipment Database. The Server version administrator will have the ability to specify additional devices. These devices will then become available for all users.

Note that exida would like to include any devices that you have reliabilty data for its equipment database, given the data passes our quality requirements. Applies to: exSILentia (All versions)  Keywords: Equipment Data, MyOwn, SERH

the exSILentia tool will enable you to determine a required SIL for a Safety Instrumented Function and calculate the achieved SIL for that Safety Instrumented Function. The calculation of achieved SIL is driven by an equipment database containing failure rates for hundreds of products. In that the exSILentia tool incorporates FMEA techniques used to determine component failure rates and because of the SIF voting selections it incorporates FTA analysis. Applies to: exSILentia (All versions)  Keywords: FMEA, FTA, SILver, SILect

We add new functionality to exSILentia on a regular basis. Minor increments are free of charge for the version of the tool you purchase (1.1, 1.2). Major Increments (new version of the tool 1.x to 2.x) will require an upgrade charge.

We release the Safety Equipment Reliability Handbook database each quarter, and you will be notified of the updates. One (1) year of Safety Equipment Reliability Handbook database updates is included with the purchase of exSILentia. After the first year a yearly maintenance fee of US $645 is required to receive Safety Equipment Reliability Handbook database updates. Applies to: exSILentia (All versions)  Keywords: Updates, SERH

exSILentia has a Parameter Update utility. This utility allows you to change some key parameters for all or a selected set of SIFs in a project. Applies to: exSILentia (All versions)  Keywords: SILver, Change parameter

The user manual is part of the CD-ROM. With the purchase of the exSILentia Standalone tool, you will also receive a printed copy of the manual, you do not have to buy it separately. If you have a good functional safety background the manual will be enough for you to learn to use the tool.

exida offers exSILentia training classes for those who want to get a quick start in using the tool and/or build confidence when using the tool. If you do not have a functional safety background exida recommends you review some of the exida online training classes on SIL verification or attend an exida functional safety training class befoe attending the exSILentia training course. Applies to: exSILentia Standalone  Keywords: User Manual, exSILentia Training

The IEC 61508 certification report is actually included on the exSILentia CD-ROM. You can access it through the tools help menu. It is also available directly from the exSILentia website:
http://www.exsilentia.com/exsilentia/exsil-downloads.asp. Applies to: exSILentia (All versions)  Keywords: Certification, IEC 61508

The list provided pretty much sums up the advantages of the standalone. We would like to add that the user interface of the standalone is also more user friendly than the on-line version simply because of the “dynamic” limitations of the web.

Yes working from home, you’ll need a laptop and the USB key. Note that exida offers discounts if you purchase more than one license at the same time. Applies to: exSILentia (All versions)  Keywords: Tool comparison, USB key

Included with the purchase of the exSILentia tool you get 1 year of equipment database updates. After the first year there is a nominal fee of US $645 per year. Any tool updates within the version e.g. 1.x will be included with your purchase.

The tool does not come with a hardcopy of the Safety Equipment Reliability Handbook. There are however special packages available in the exida online store that include the tool, the book and free shipping. Applies to: exSILentia (All versions)  Keywords: SERH

Indeed equipment database updates are included during the first year after purchase. After the first year exida charges US $745 per year for equipment database updates.

The exSILentia standalone minor revisions / updates are free and available for download via www.exSILentia.com. Any Major revision / new version (1.x to 2.x) will require you to upgrade, if you want to continue receiving software upgrades. There will be a discount / reduced price / upgrade price for existing exSILentia users when a Major revision is released. Applies to: exSILentia Standalone  Keywords: Updates, Equipment Database

While we are working on a modification plan to include relay logic as one of the Safety PLC selection options, we currently do not have that ability (directly). There is a workaround however; instead of selecting a logic solver from the dropdown you should select “MyOwn”. This will allow you to enter your own logic solver.

Workaround:
exida suggests you use the following reliability data for the relay logic solver. The relay logic solver is a relay plus power supply combination (otherwise you will not be able to power field equipment).

Relay failure rates:
Safe Detected = 0
Safe Undetected = 9.00E-07 /hr
Dangerous Detected = 0
Dangerous Undetected = 6.00E-07 /hr

Power supply failure rates:
Safe Detected = 0
Safe Undetected = 2.48E-06 /hr
Dangerous Detected = 0
Dangerous Undetected = 3.21E-08 /hr

Combined failure rate data for the MyOwn relay plus power supply combination Logic Solver
Component: Relay + Power Supply
Voting: 1oo1
Failure Rates (1/hr)
* Safe Detected = 0
* Safe Undetected = 3.3779E-06
* Dangerous Detected = 0
* Dangerous Undetected = 6.3213E-07

Architectural Constraint Type: A
Beta (%): 0

There may be several reasons why an equipment item is not listed.

1. If the data is available, the equipment item may not be listed in the equipment database since the data did not meet exida's quality requirements.

2. exida may not be aware that data for a specific equipment item is available. Please let us know and we will add the device once we review the reliability data and confirm the data is adequate for use in functional safety calculations.

Please contact exida at serh@exida.com for more information.

If reliability data is not available for a device, please contact the manufacturer and explain that his equipment is used in functional safety applications where reliability data is required to determine safety integrity level applicability. exida can help the manufacturer perform a Failure Modes, Effects, and Diagnostic Analysis to determine the reliability data for an equipment item.

If you have reliability data that is proprietary you can use this data by selecting a "MyOwn" device and enter the data manually. Applies to: exSILentia (All versions)  Keywords: SILver, MyOwn, Equipment

The limitation of SILver to de-energize-to-trip functions is caused by the reliability data in the equipment database. To be more precise the reliability data for digital equipment. As an example a short on a switch would be considered dangerous in a de-energize-to-trip application whereas the shorting of the switch would initiate the safety function in an energize-to-trip application and therefore would be safe.

Other than the reliability data there is virtually no difference in the reliability calculations, a 1oo2 configuration uses the same Markov model for energize-to-trip as for de-energize-to-trip. The main difference is the way the components will be connected in the process.

You can model energize-to-trip functions; however you need to be careful when selecting equipment from the equipment database. Applies to: exSILentia (All versions)  Keywords: SILver, Energize-to-Trip

To calculate the PFDavg of a single device, select the device in SILver and select "<none>" for all other devices in the group. This will exclude everything except the device you would like to analyze. Applies to: exSILentia (All versions)  Keywords: SILver, PFDavg

How do I model the configuration shown in the accompanying figure?

The easiest way to model this is by considering the three relays part of the sensor (after all they are on the same channels).

A) Define a single sensor group with 1oo3 (assuming 1oo3 voting), diverse technology. For leg 1 and 2 select temperature transmitter with RTD for Sensor and for leg 3 select a Level Switch for sensor. For all three legs select an IS Barrier for Interface Module 1 and a Relay for Interface Module 2.

B) Define a final element group with the final element being a relay.

C) For the logic solver select a "MyOwn" logic solver. Instead of entering the failure rates for a single wire, you also need to consider the power supply needed to power this SIF. Compared to the power supply the wire is negligible; therefore enter the following data for your "MyOwn" logic solver;

Component: Power Supply
Voting: 1oo1
Failure Rates (1/hr)
* Safe Detected = 0
* Safe Undetected = 2.48E-06
* Dangerous Detected = 0
* Dangerous Undetected = 3.21E-08

Architectural Constraint Type: A
Beta (%): 0 Applies to: exSILentia (All versions)  Keywords: SILver, Relay Logic

Yes. We intend to allow the user to specify all detailed failure rates for a Logic Solver in a future version of exSILentia through an advanced user option. We also will continue to support the current option to enter only a single set of failure rates for the Logic Solver.

Workaround:
Combine the failure rates of the individual modules and enter the result as a MyOwn Logic Solver.

exSILentia / SILver currently does not alert you to equipment data changes. However, we are planning on adding this feature in the version 2 release of exSILentia. Applies to: exSILentia (All versions)  Keywords: SILver, Equipment Database

Yes. We intend to add a page to show the contributions that each group makes to the part PFDavg and MTTFS. Note that the group contribution bar graphs are already part of the reports that are generated by the online version of exSILentia. Applies to: exSILentia Online  Keywords: SILver, PFDavg, MTTFS

Yes. We intend on adding a Bill of Materials Report to exSILentia. We are also working together with some Safety PLC manufacturers to automatically generate (part of) the logic solver programming. Applies to: exSILentia (All versions)  Keywords: SILver, Bill of Materials

Yes, we are planning to add additional fields for reviewers in addition to the current fields for analysts. In addition users will be able to specify tool users and user roles, engineer / analyst vs. reviewer. Applies to: exSILentia (All versions)  Keywords: Reviewer

Currently this is not possible. However, we are working on a method of versioning the data in the Safety Equipment Reliability Handbook (SERH) so that it can be saved with the project, and also displayed in the Reports. Applies to: exSILentia (All versions)  Keywords: SILver, Equipment Database

Yes. We are working on a modification plan to include relay logic. If you currently need to include a relay as your logic solver use the workaround described in the modeling issues section of this FAQ. Applies to: exSILentia (All versions)  Keywords: SILver, Relay, Logic Solver

In exSILentia you are already able to identify Groups as reusable. This is intended to be used for groups in different SIFs that represent identical hardware. Once you have identified a group for reuse, you can select that group from a dropdown list when you specify a new SIF. When you make changes to a reused group in any of the SIFs the changes will be applied to all SIFs where the group is used.

exSILentia version 2 will have a group copy functionality that will allow users to copy groups between and within a SIF. Applies to: exSILentia (All versions)  Keywords: SILver, Reuse Groups

Yes. We plan to add these fields to make the Risk Graph more flexible in version 2 of exSILentia. Applies to: exSILentia (All versions)  Keywords: SILect, Risk Graph

You can use a little probability trick to convert a calculated average Probability of Failure on Demand and MTTFS to failure rates for use in a subsequent SIF. Use SILver to generate your PFDavg and MTTFS, then convert that to a dangerous undetected failure rate and a safe undetected failure rate using the following approximation formula FailDU = (2 * PFDavg) / Proof Test Interval and FailSU = 1 / (MTTFS * 8760) respectively [8760 to convert from years to hours].

We are also planning to develop this ability directly into exSILentia, where we will allow you to save the output of a Group or Part as a "MyOwn" device for use in another Group. Applies to: exSILentia (All versions)  Keywords: SILver, Complex voting, MyOwn

We already have a PHA import utility that is currently sold as a separate tool. exSILentia version 2 will include optional modules or plug-ins. The PHA import utility will then be fully integrated with exSILentia.

The PHA import utility works with PHA Pro, PHA Works and CSV files. Applies to: exSILentia (All versions)  Keywords: HAZOP, SIF List

Yes, we plan on expanding the languages of our reports to include German and Portuguese in exSILentia version 2. We also have been expanding the ability of the reports to handle extended characters for use in Korean, Chinese, Japanese and other languages. Applies to: exSILentia (All versions)  Keywords: Reports, Language

We are planning to add an "Error / Compliance" checker utility to exSILentia. The intent is to add the "error / compliance report" to the analysis report but also make it available as a separate report. Applies to: exSILentia (All versions)  Keywords: Error checking, Standard Compliance

exSILentia does not support this directly. You would have to do a Layer of Protection analysis separate and enter the resulting frequency in the Hazard Matrix. We intend to add the ability to associate IPLs with Hazard Matrix and Risk Graph directly. Applies to: exSILentia (All versions)  Keywords: SILect, LOPA, Hazard Matrix, Risk Graph

We are planning to add a "News and hints" feature to exSILentia that will provide updated information about the tool and try to give you helpful hints about using the tools. Applies to: exSILentia Online  Keywords: Hints, News