If you do not have a vibration tester it can be really difficult to use other companies’ former data.
Products are so different that you really do not know what critical natural frequencies such a new product may have. If you do not have a vibration table you can sometimes spot some of the natural frequencies by knocking the product hard and listen to the sounds from the product from after vibrations. Otherwise your only possible solution will be to use a public packaging testing laboratory.
Pallets with corrugated or plastic boxes have a high number of natural frequencies because there between the layers are the same spring constant but different loads on top. Practical experiences from many tests demonstrate 4-10 different natural frequencies between 2-20 hz. Unfortunately this is a frequency area in truck, train, ship and airplane transport with many inputs.