Sci-Dog sorry only just logged on so couldn't post a reply in time to your PM.
However, I think all the useful posts above have given you the right information so hopefully it went well.
Points to consider for anyone else facing the same situation:
There is no nationally agreed prep-rate for the whole delivery
The daily traffic figures for the whole office do not take into account local variances from walk to walk. For instance I had one mailing for every DP on my duty today - the guy next to me did not. So he was prepped and ready to go about 1/2 hour before I was.
The daily traffic figures are also useless when it comes to call rate or attendance rate for the same reason.
The prep-rate (even without a national agreement so not recognised by the CWU) includes time taken to get packet bags,coded bundles, IPs sorted and missort bundles but this is not taken onto account when working out the rate. For instances if you have to walk the furthest from the IPs and DBFs your prep rate is bound to be slightly slower than a duty which is right next to it.
There is an agreed sorting test of (one in downloads) but even then they should not discipline you for failing but counsel you and arrange training to get you up to speed.
Anyway once again apologies but hope it went well, if not there is always the grievance route if they discipline you.
I thought no one is supposed to leave the office before ten? or is that another 'rule' that can be changed at wiill?