Kenexis Effigy™ Fire and Gas Mapping Software is a state-of-the-art fire and gas mapping tool that utilizes consequence-based models to calculate coverage.

Historical Background

Fire and gas system design has historically been a challenge. The design of systems was based on inconsistent rules of thumb that resulted in widely varying requirements. In an effort to standardize the process for the design of fire and gas systems, industry experts, including the pioneers at Kenexis, developed the ISA 84.00.07 Technical Report. This built on the performance-based quantitative approaches of the ISA 84 / IEC 61511 process safety standards. The technical report clarified performance-based methods for the placement of fire and gas detectors.

Since the release of the technical report, process safety management focused companies have incorporated the concept of achieving quantitative coverage targets (performance-based) into their fire and gas design processes. With the advent of fire and gas mapping software, such as Kenexis Effigy™, to analyze for coverage targets using sophisticated computerized tools, process safety has taken another significant step forward.


As part of the original team of experts that developed the techniques described in the ISA 84.00.07 Technical Report, Kenexis was charged with developing the software that would perform calculations based on the metrics that the technical report defined. Through several years of research and extensive validation, Kenexis developed an unparalleled software solution that performs coverage calculations with a degree of sophistication and accuracy unrivaled by any other software or method.

Fire and Gas Coverage Calculation

At the heart of the Effigy fire and gas mapping software is an algorithm for the calculation of the coverage, both geographic and scenario based, that considers the specific application, equipment, and instrumentation used in the facility under study. Consider the following features of the calculation engine:

  • Analyzes fully in three dimensions, including, detector cone-of-vision manipulation, obstruction location, and obstruction shadow orientation
  • Calculates results for any user selected elevation of interest – multiple elevations if required
  • Accurately and specifically models any brand of detector, and separately assesses all documented sensitivity settings of those detectors
  • Includes a database of most common fire and gas detection equipment and associated performance metrics
  • Accurately models cone-of-vision projections as detectors are moved away from the elevation of interest and rotated away from parallel
  • Accurately model different materials of interest for each detector as required (e.g., methane, hexane, methanol)
  • Analyzes modeling of multiple obstruction geometries, including cubes (cuboid), sphere, cylinders, cylindrical vessels (horizontal and vertical), in all rotations and orientations
  • Presents tabular results of areas where 1) no detectors are sighted, 2) one detector is sighted, and 3) two or more detectors are sighted
  • Presents color-coded graphical coverage maps indicating extent of the various coverage areas
  • Limits graphic and tabulated results to the areas of interest as defined in grading maps, in addition to the results of the overall zone
  • Presents multiple and independent results for each of the multiple graded areas of each zone

In addition to the more common geographic coverage, Effigy Fire and Gas Mapping Software also presents scenario coverage maps. These maps provide a geographic risk profile the combines all of the thousands of scenarios that are possible in a zone, and also provides a mitigated risk profile that only maps the scenarios that are not detected by the fire and gas detector array — along with a tabulated calculation of the fraction of the scenarios that are detected. The results of scenario analysis are plotted as color-coded isopleths of constant release frequency.

Comprehensive Integrated Software

The Kenexis Effigy™ Fire and Gas Mapping Software is part of the integrated-online engineering software from Kenexis. Our secure cloud-based model is accessed by any licensed user on any computer or tablet through a standard browser. The unique architecture ensures that your software is always available and up to date with the latest performance metrics and resource databases. Our solution makes it easy for a licensed user to share project information with others including contracts, EPCs, and to leverage Kenexis process safety engineers for project assistance, outsourcing, and verification and certification of your analyses.

  • Compatibility with most browsers in most operating systems
  • Extensive standard and custom equipment databases
  • Detailed technical documentation and help
  • Dedicated help desk and support
  • Reports and graphical results output and export