Hi
I'm a Timber Chain of Custody Consultant and I also conduct certification audits for a CB in the UK.
Because initial audits against the FSC and PEFC standards are audits of your intentions, as you are not able to certify material until you receive your certificate, the audit mainly looks at your procedures and the training given to your employees.
The quickest I have taken a company through the certification process is 5 days. I created some draft procedures based on my knowledge of requirements. I visited them on a Monday to train their key employees and determine the accuracy of the procedures. On Tuesday I carried out some amendments and sent their manual. They received it on Thursday and were assessed by SGS on the Friday of the same week - with not one single non-conformance. SGS is not the CB I audit for incidentally.
Anyone who tells you there is a lot of work involved and it will take up to 3 months is doing so to make money for themselves, and there are a lot of Consultants like that in the UK.
On the issue of the Material Conversion Factor. FSC require the material conversion factor for each of your product groups - not each individual product or job. If you make windows, that is your product group.
You then calculate roughly how much waste you produce at each processing step, or total steps if that is more feasible, and the material in the finished product as a % of the material at the start, is the conversion factor. Most companies are aware of their overall waste %, so use that to start with.
The methodology for calculating it would be something like "The average yield after all sawing planing and other processes have been carried out".
Monitor the conversion factor to ensure it remains accurate.
The purpose of the conversion factor is to consolidate your sales summary with your purchase summary.
If you declare a conversion factor of 80% and buy 10M3 of FSC timber but subsequently claim sales totalling 9M3, FSC (the auditor) would want to know where the additional 1M3 came from, as you would have stated that only 8M3 of the initial 10M3 would be in your finished products.
I hope this helps.