First of all - information based on which assumption are being created. We can divide them into 2 main groups: information regarding distribution of the product and rotation. More details are presented on the graph.
After receving all of those information you can either find a similar product and adjust its volume to current assumption accordingly or if there is no predecessor you can try to get data from competitor's products (e.g. based on Nielsen databases).
Finally, calculations can be made. Here is the example.
1. Each of the variable has its weight and price has the biggest (80%), then discount and advertising has 10 each.
2.% differencies are being calculated in colums H5:H7. Price indicatior has reversal sign. Higher price is actually worsed than lower.
3. With help of sumproduct funtion final hitrate is calculated (H8).
4. At the end of process volumes per each channel are multiplied by this hitrate and results are given in cells G11:G26.
This is how your volume is calculated :) For more information don't hesitate to contact me !