Factors:

Test Results
System Efficiency
System Softness
Impact performance of the SE
Observations
Function of the net
Warranty Analysis
Cost of Ownership - CoO

Test Results
System Efficiency testing is performed by dropping a weight onto the jumping surface and precisely measuring the rebound.  Our testing methodology has allowed us to test the efficiency at a number of different weights. The range that we have tested is from 60 to 225 lbs. We believe that we can use our system to well over 300lbs. Setting different weights on the trampoline and measuring mat deflection enables us to determine the system static spring rate, which is related to softness. Testing of this type is performed in a laboratory and often utilizes a variety of weights for a given system.  The benefit of performing these tests is that we can quantify a variety of different types of trampolines and obtain results that can be compared.   In addition to performing tests on trampolines, we also perform a variety of tests on safety enclosures.  A full range of enclosure tests includes impacting the net, poles and door with a large heavy weight to simulate the weight of a jumper doing the same.  

Warranty Analysis
For each of the trampoline systems tested, our rankings focused on six specific components. These consisted of  the frame, enclosure poles, enclosure net, jumping mat, spring elements (including steel coil springs, bands and spring rods), and pads. For each trampoline system we collected the data for the duration of the warranty covering each component area. The a scale for the duration of each component category ranged from no warranty to the longest duration warranty of the testing group, and was interpolated to assign rating values for each model. The overall rating score for each trampoline system was calculated using the equally weighted average of the ratings for each component of that trampoline.
 
Cost of Ownership
It is important to put a dollar value on the annual cost of ownership for any major item such as a trampoline. Like any piece of mechanical equipment subjected to rigorous use and exposed to the elements, many of the components of a trampoline can wear out. Longevity and durability varies greatly between different models, and repair or replacement costs can add up quickly for parts no longer covered by a warranty.

We took the warranty coverage length for each of the six components, and found the total replacement cost for each. Of the total cost, we estimated that for component types such as the frame, enclosure poles, and spring elements parts, only a portion of the total parts would fail and need to be replaced. We estimated the percentage for each component group and, applied that to the total cost of each group. The enclosure net, jumping mat, and pad we assumed would require 100% replacement. Considering that the life expectancy for each component is correlated to the manufacturer’s warranty coverage, it was assumed that on average each would last approximately 3 times the length of its actual coverage. Based on these inputs, the total annual cost of ownership for each trampoline system was calculated.