The article deals with methodology of a system failure rate calculation that is based on the adoption of the condition l. t<<1. Assuming that the condition is satisfied. the serial-parallel system failure rate calculation is easier and the results are either the same or worse from a view of system reliability evaluation. https://www.bekindtopets.com/hot-deal-NFL-Denver-Broncos-Super-Bowl-50-Champions-Apple-AirPods-2-Skin-p13681-great-buy/