Tan,
This post should not be diversifying from the subject in hand however I can only presume you work for a healthy passenger airline. Here, we are talking about the rough and tough cargo world.
Sure, I've produced many 'max fuel' computerised flight plans in my career but the systems I worked with only took into consideration aircraft performance and not airfield performance.
It's all very well for an Ops guy to produce such a flight plan but I doubt airfield conditions were taken into consideration, not just the modest runway length but was it contaminated, what was the surface wind, what flap settings were the crew to use etc.
Whether it be via a flight crew notice or a computerised flight plan, the operator would need to notify the Capt. of fuel prices for him to accertain if it was financially beneficial to tanker or not, of course the Capt. would need to take into consideration the RTOW which Ops, at best, would have been only able to second guess at when producing the flight plan.
All your most recent of post does is talk about the flight planning equipment available, I said 3+%, you say 4% so we don't disagree there however I don't believe any Captain should believe a flight plan will tell him EXACTLY how much fuel will be burnt, it'll only do that if it has the winds, payload etc. spot on and those winds may have been forecast some 12 hours previously.
I've never known a Capt. who believes that the flight plan has the fuel burn EXACT! All I said in my original post was that the fuel in YHZ would have to be significantly cheaper to make tankering fuel viable, on your figure of 4% and let's call it a 6 hour leg then it would need to be 25% cheaper to make it viable, I stand by my original post and your writings have not said a single word in dispute of this.