I’m replying to the last article and the formula mentioned for calculating offered traffic only took into consideration No. of Available Cct and Carried Traffic. This formula only works if your offered traffic is less than the total capacity of your trunk group (or whatever is carrying your traffic). To accurately assess offered traffic you need to know how many calls could not complete due to insufficient capacity (e.g. overflows).
I’m going from memory here but if I recall correctly a standard formula is Carried_Traffic / (1 – (overflow/attempts)).