Dear Colleagues,

I have been reading this POE conversation with extreme interest, thank you all for your contributions.

It is ironic that the last entry in the thread had to do with roofing contractors; I had this exact scenario... The roofers drove a nail (a staple actually) and it penetrated a 240 volt branch circuit - resistance heating through the staple ignited the plywood underlay. Don't rule out hypotheses too quickly or casually...

FWIW, the Bilancia Ignition Matrix(tm) was not designed to be complicated, rather it was designed to simplify requirements for documenting fuels, heat sources, and hypotheses; it was designed to meet the NFPA 921 and 1033 requirements that all heat sources and all potential first ignited fuels are considered and documented. ASTM E678-07 requires a documented rationale for ruling a hypothesis in or out:

4.1.3 Evaluation Techniques:
4.1.3.1 Prepare and maintain a logical and traceable record
of analysis and deduction.

I was in the midst of contemplating ritual seppuku after a 10 hour deposition when the epiphany hit on how to address the deposing lawyer's large list of heat sources and fuels could be summarized.

Since then the BIM has been successfully used in trial.

Best Regards,