The useful life of an SSD is governed by three key parameters:

SSD NAND flash technology
capacity of the drive
the application usage model

In general the following life cycle calculator can be used to figure how long the drive will last.

Life [years] = (Endurance [P/E cycles] * Capacity [physical, bytes] * Overprovisioning Factor) / (Write Speed [Bps] * Duty Cycle [cycles] * Write % * WAF) / (36 *24* 3,600)

Parameters:

Endurance, NAND P/E Cycle: 100K SLC, 30K eMLC, 3K MLC
Capacity: Usable capacity of the SSD
Overprovisioning Factor: Over provision NAND percentage
Write Speed: Speed of write in Bytes per second
Duty Cycle: Usage duty cycle
Write %: percentage of writes during SSD usage
WAF: Controller Write Amplification factor computed based on application use case