The product I'm working on designing simplifies down to a relatively simple three-spring system, which is easily calculated. Unfortunately our company president is weighing in on the design, and doesn't agree with the calculation, and insists the result is something different (based on a fundamentally wrong assumption). I've outlined the problem with a diagram in the attached PDF. At the bottom there are the two different assumptions which were used to come up with the two different results, any assistance into which theory is correct would be greatly appreciated. Thanks.